Patent Publication Number: US-2022236530-A1

Title: Optical photographing lens assembly, image capturing unit and electronic device

Description:
RELATED APPLICATIONS 
     This application claims priority to Taiwan Application 110102954, filed on Jan. 27, 2021, which is incorporated by reference herein in its entirety. 
     BACKGROUND 
     Technical Field 
     The present disclosure relates to an optical photographing lens assembly, an image capturing unit and an electronic device, more particularly to an optical photographing lens assembly and an image capturing unit applicable to an electronic device. 
     Description of Related Art 
     With the development of semiconductor manufacturing technology, the performance of image sensors has improved, and the pixel size thereof has been scaled down. Therefore, featuring high image quality becomes one of the indispensable features of an optical system nowadays. 
     Furthermore, due to the rapid changes in technology, electronic devices equipped with optical systems are trending towards multi-functionality for various applications, and therefore the functionality requirements for the optical systems have been increasing. However, it is difficult for a conventional optical system to obtain a balance among the requirements such as high image quality, low sensitivity, a proper aperture size, miniaturization and a desirable field of view. 
     SUMMARY 
     According to one aspect of the present disclosure, an optical photographing lens assembly includes five lens elements. The five lens elements are, in order from an object side to an image side along an optical path, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. Each of the five lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. 
     The first lens element has negative refractive power, and the object-side surface of the first lens element is concave in a paraxial region thereof. The five lens elements include at least one freeform lens element, and at least one of the object-side surface and the image-side surface of the at least one freeform lens element is a freeform surface. 
     When a paraxial curvature radius of the object-side surface of the first lens element in a maximum image height direction is R1, and a focal length of the optical photographing lens assembly in the maximum image height direction is f, the following condition is satisfied: 
       −4.5&lt; R 1/ f&lt;− 0.30.
 
     According to another aspect of the present disclosure, an optical photographing lens assembly includes five lens elements. The five lens elements are, in order from an object side to an image side along an optical path, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. Each of the five lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. 
     The object-side surface of the first lens element is concave in a paraxial region thereof. The five lens elements include at least one freeform lens element, and at least one of the object-side surface and the image-side surface of the at least one freeform lens element is a freeform surface. 
     When a focal length of the optical photographing lens assembly in a maximum image height direction is f, and a composite focal length of the fourth lens element and the fifth lens element in the maximum image height direction is f45, the following condition is satisfied: 
       1.9&lt; f 45/ f.    
     According to another aspect of the present disclosure, an optical photographing lens assembly includes five lens elements. The five lens elements are, in order from an object side to an image side along an optical path, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. Each of the five lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. 
     The first lens element has negative refractive power. The second lens element has positive refractive power. The image-side surface of the fifth lens element is concave in a paraxial region thereof. The five lens elements include at least one freeform lens element, and at least one of the object-side surface and the image-side surface of the at least one freeform lens element is a freeform surface. 
     When a central thickness of the first lens element is CT1, and a central thickness of the fourth lens element is CT4, the following condition is satisfied: 
       0.38&lt; CT 1/ CT 4&lt;1.9. 
     According to another aspect of the present disclosure, an image capturing unit includes one of the aforementioned optical photographing lens assemblies and an image sensor, wherein the image sensor is disposed on an image surface of the optical photographing lens assembly. 
     According to another aspect of the present disclosure, an electronic device includes the aforementioned image capturing unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure can be better understood by reading the following detailed description of the embodiments, with reference made to the accompanying drawings as follows: 
         FIG. 1  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 1st embodiment of the present disclosure; 
         FIG. 2  shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 1st embodiment; 
         FIG. 3  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 2nd embodiment of the present disclosure; 
         FIG. 4  shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 2nd embodiment; 
         FIG. 5  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 3rd embodiment of the present disclosure; 
         FIG. 6  shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 3rd embodiment; 
         FIG. 7  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 4th embodiment of the present disclosure; 
         FIG. 8  shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 4th embodiment; 
         FIG. 9  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 5th embodiment of the present disclosure; 
         FIG. 10  shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 5th embodiment; 
         FIG. 11  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 6th embodiment of the present disclosure; 
         FIG. 12  shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 6th embodiment; 
         FIG. 13  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 7th embodiment of the present disclosure; 
         FIG. 14  shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 7th embodiment; 
         FIG. 15  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 8th embodiment of the present disclosure; 
         FIG. 16  shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 8th embodiment; 
         FIG. 17  is a perspective view of an image capturing unit according to the 9th embodiment of the present disclosure; 
         FIG. 18  is one perspective view of an electronic device according to the 10th embodiment of the present disclosure; 
         FIG. 19  is another perspective view of the electronic device in  FIG. 18 ; 
         FIG. 20  is a block diagram of the electronic device in  FIG. 18 ; 
         FIG. 21  is one perspective view of an electronic device according to the 11th embodiment of the present disclosure; 
         FIG. 22  is one perspective view of an electronic device according to the 12th embodiment of the present disclosure; 
         FIG. 23  shows a superposition of ImgHX, ImgHY, ImgHD and surface shapes of the image-side surface of the fifth lens element corresponding to the diagonal direction, a lengthwise direction and a widthwise direction of the photosensitive area of the image sensor according to the 1st embodiment of the present disclosure; 
         FIG. 24  shows an enlarged view of the region AA in  FIG. 23 ; 
         FIG. 25  shows a schematic view of Ymin, CTF, SAG, a cross-sectional view of the fifth lens element corresponding to the widthwise direction of the photosensitive area of the image sensor and a front view of the image-side surface of the fifth lens element according to the 1st embodiment of the present disclosure; 
         FIG. 26  is a data graph of SAG of all positions at a distance of Ymin from the optical axis on the image-side surface of the fifth lens element according to the 1st embodiment of the present disclosure; 
         FIG. 27  is a schematic view of a configuration of the fifth lens element and the image sensor according to the 1st embodiment of the present disclosure; 
         FIG. 28  shows a schematic view of Y11, Y52, and critical points of the first and fifth lens elements according to the 1st embodiment of the present disclosure; 
         FIG. 29  shows a schematic view of an imaging area of the image sensor and ImgHX, ImgHY and ImgHD according to the 1st embodiment of the present disclosure; 
         FIG. 30  shows a schematic view of a configuration of a light-folding element in an optical photographing lens assembly according to one embodiment of the present disclosure; 
         FIG. 31  shows a schematic view of another configuration of a light-folding element in an optical photographing lens assembly according to one embodiment of the present disclosure; and 
         FIG. 32  shows a schematic view of a configuration of two light-folding elements in an optical photographing lens assembly according to one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     An optical photographing lens assembly includes five lens elements. The five lens elements are, in order from an object side to an image side along an optical path, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. Each of the five lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. 
     According to the present disclosure, the five lens elements of the optical photographing lens assembly include at least one freeform lens element, and at least one of the object-side surface and the image-side surface of the at least one freeform lens element is a freeform surface. Therefore, the freeform lens element is favorable for correcting aberrations such as distortion; furthermore, capturing low-distortion images is favorable for the optical photographing lens assembly to be applicable to various applications, especially for wide field-of-view designs. In the present disclosure, a freeform surface (FFS) is a non-axisymmetric aspheric surface. Moreover, at least one of the first lens element and the fifth lens element can be a freeform lens element. Therefore, it is favorable for reducing the influence of non-axisymmetric lens elements on the assembling process, thereby increasing assembling yield rate. Please refer to  FIG. 23  and  FIG. 24 .  FIG. 23  shows a superposition of ImgHX, ImgHY, ImgHD and surface shapes of the image-side surface of the fifth lens element corresponding to a diagonal direction, a lengthwise direction and a widthwise direction of the photosensitive area of the image sensor according to the 1st embodiment of the present disclosure, and  FIG. 24  shows an enlarged view of the region AA in  FIG. 23 .  FIG. 24  shows the difference of the surface shapes DS, XS, YS of the image-side surface  152  of the fifth lens element  150  corresponding to the diagonal direction, the lengthwise direction and the widthwise direction of the photosensitive area of the image sensor  180  at the same distance from an optical axis, which can be exemplary of the non-axisymmetric aspheric surface. 
     According to the present disclosure, a minimum value among distances between the optical axis and a boundary of an optically effective area of one lens surface is Ymin, a displacement in parallel with the optical axis from an intersection point between the lens surface and the optical axis to a position at a distance of Ymin from the optical axis on the lens surface is SAG, a maximum value among all the displacements SAG is SAG_MAX, and a minimum value among all the displacements SAG is SAG_MIN. When an absolute difference between SAG_MAX and SAG_MIN is |dSAG|max, at least one freeform surface of at least one freeform lens element of the optical photographing lens assembly can satisfy the following condition: 0.45 um&lt;|dSAG|max. Therefore, it is favorable for increasing the shape variation of the freeform surface so as to further correct aberrations. Moreover, the following condition can also be satisfied: 0.60 um&lt;|dSAG|max. Moreover, the following condition can also be satisfied: 0.75 um&lt;|dSAG|max. Please refer to  FIG. 25  and  FIG. 26 .  FIG. 25  shows a schematic view of Ymin, SAG, a cross-sectional view of the fifth lens element corresponding to the widthwise direction of the photosensitive area of the image sensor and a front view of the image-side surface of the fifth lens element according to the 1st embodiment of the present disclosure, and  FIG. 26  is a data graph of SAG of all positions at a distance of Ymin from the optical axis on the image-side surface of the fifth lens element according to the 1st embodiment of the present disclosure. When the displacement from the intersection point between one freeform surface and the optical axis to a point at a distance of Ymin from the optical axis on the same surface is facing towards the image side of the optical photographing lens assembly, the value of displacement is positive; when the displacement from the intersection point between the freeform surface and the optical axis to a point at a distance of Ymin from the optical axis on the same surface is facing towards the object side of the optical photographing lens assembly, the value of displacement is negative. In  FIG. 25 , there is a minimum distance Ymin between the optical axis and the boundary of the optically effective area of the image-side surface  152  of the fifth lens element  150  in the direction corresponding to the widthwise direction Y of the photosensitive area of the image sensor.  FIG. 26  shows the values of displacements SAG of all positions at a distance of Ymin from the optical axis on the image-side surface  152  of the fifth lens element  150 , where the horizontal axis represents the angle θ between the positive X-axis and a dotted line as shown in  FIG. 26 , the angle θ is 0 degree as the dotted line is at the positive X-axis, and the angle θ increases as the dotted line rotates counterclockwise about the Z-axis; the vertical axis represents the displacements SAG corresponding to various angles  6 . As seen in  FIG. 25  from the front view of the image-side surface  152  of the fifth lens element  150 , there can be one SAG value at any position in a distance of Ymin from the optical axis on the image-side surface  152  of the fifth lens element  150 . For example, when the angle θ is 0 degree, there is a corresponding SAG value equal to 0.367 mm at the position P 1  at a distance of Ymin from the optical axis on the image-side surface  152  of the fifth lens element  150 ; when the angle θ is 90 degrees, there is a corresponding SAG value equal to 0.382 mm at the position P 2  at a distance of Ymin from the optical axis on the image-side surface  152  of the fifth lens element  150 . As seen in  FIG. 26 , there can be a maximum value SAG_MAX and a minimum value SAG_MIN among all displacements SAG, and the absolute difference between SAG_MAX and SAG_MIN is |dSAG|max. 
     When the absolute difference between SAG_MAX and SAG_MIN is |dSAG|max, and a central thickness of one freeform lens element is CTF, at least one freeform surface of at least one freeform lens element of the optical photographing lens assembly can satisfy the following condition: 1.00E-3&lt;|dSAG|max/CTF. Therefore, it is favorable for increasing the shape variation of the freeform surface so as to further correct aberrations. Please refer to  FIG. 25 , which shows a schematic view of CTF according to the 1st embodiment of the present disclosure. 
     According to the present disclosure, one lens surface of the freeform lens element can have an optically non-effective area at the periphery of freeform lens element and does not overlap the optically effective area. The freeform lens element can have at least one positioning structure at the optically non-effective area. Therefore, it is favorable for the maximum image height direction to correspond to the image sensor during the assembling process. Moreover, the freeform lens element can also have at least two positioning structures at the optically non-effective area. Moreover, the positioning structure can include a flat cut line. Therefore, it is favorable for increasing the recognizability of the positioning structure. Please refer to  FIG. 27 , which is a schematic view of a configuration of the image sensor  180  and the fifth lens element  150  according to the 1st embodiment of the present disclosure. In the 1st embodiment, the fifth lens element  150  is a freeform lens element and has two positioning structures PSR at the region thereof (optically non-effective area) outside its optically effective area OEA, and each of the positioning structures PSR includes a flat cut line. The fifth lens element having positioning structures in  FIG. 27  according to the 1st embodiment is only exemplary. Other freeform lens elements in various embodiments of the present disclosure can also have similar positioning structures. 
     The first lens element can have negative refractive power. Therefore, it is favorable for increasing the field of view. The object-side surface of the first lens element can be concave in a paraxial region thereof. Therefore, it is favorable for increasing the field of view and reducing the size at the object side of the optical photographing lens assembly. The object-side surface of the first lens element can have at least one critical point in an off-axis region thereof and in a maximum image height direction. Therefore, it is favorable for adjusting the incident direction of light rays on the first lens element so as to improve image quality of light rays at wide field of view on an image surface. 
     The second lens element can have positive refractive power. Therefore, it is favorable for reducing the total track length of the optical photographing lens assembly. The object-side surface of the second lens element can be convex in a paraxial region thereof. Therefore, it is favorable for collaborating with the first lens element so as to enlarge the field of view. The image-side surface of the second lens element can be convex in a paraxial region thereof. Therefore, it is favorable for adjusting the travelling direction of light so as to balance the size distribution between the object side and the image side of the optical photographing lens assembly. 
     The image-side surface of the third lens element can be concave in a paraxial region thereof. Therefore, it is favorable for correcting aberrations such as astigmatism. 
     The fourth lens element can have positive refractive power. Therefore, it is favorable for balancing the refractive power distribution of the optical photographing lens assembly so as to reduce sensitivity of the optical photographing lens assembly. The image-side surface of the fourth lens element can be convex in a paraxial region thereof. Therefore, it is favorable for collaborating with the fifth lens element so as to correct off-axis aberrations. 
     The fifth lens element can have negative refractive power. Therefore, it is favorable for balancing the refractive power at the image side of the optical photographing lens assembly so as to correct aberrations such as spherical aberration. The object-side surface of the fifth lens element can be convex in a paraxial region thereof. Therefore, it is favorable for collaborating with the fourth lens element so as to correct aberrations. The object-side surface of the fifth lens element can have at least one critical point in an off-axis region thereof and in the maximum image height direction. Therefore, it is favorable for adjusting the angle of incident light rays on the fifth lens element so as to reduce stray light. The image-side surface of the fifth lens element can be concave in a paraxial region thereof. Therefore, it is favorable for adjusting the back focal length of the optical photographing lens assembly. The image-side surface of the fifth lens element can have at least one critical point in an off-axis region thereof and in the maximum image height direction. Therefore, it is favorable for adjusting the angle of incident light rays on the image surface so as to improve the response efficiency of the image sensor. Please refer to  FIG. 28 , which shows a schematic view of the critical points C of the first lens element  110  and the fifth lens element  150  in the maximum image height direction according to the 1st embodiment of the present disclosure. The critical points of the object-side surface of the first lens element, the object-side surface of the fifth lens element and the image-side surface of the fifth lens element in the maximum image height direction are only exemplary. The object-side surface and the image-side surface of each lens element in various embodiments of the present disclosure can also have one or more critical points in an off-axis region thereof and in the maximum image height direction. Said maximum image height direction is a direction corresponding to a maximum distance between the optical axis and an imaging position on an image sensor. For example, please refer to  FIG. 23  and  FIG. 29 , where  FIG. 23  shows a superposition of ImgHX, ImgHY and ImgHD corresponding to the diagonal direction, the lengthwise direction and the widthwise direction of the photosensitive area of the image sensor according to the 1st embodiment of the present disclosure, and  FIG. 29  shows a schematic view of an imaging area of the image sensor and ImgHX, ImgHY and ImgHD according to the 1st embodiment of the present disclosure. In  FIG. 29 , a direction of light travelling along the optical axis into the image sensor  180  is the positive Z-axis direction, a direction corresponding to the lengthwise direction of the photosensitive area of the image sensor  180  is the X-axis direction, a direction corresponding to the widthwise direction of the photosensitive area of the image sensor  180  is the Y-axis direction, ImgHX is a maximum distance between the optical axis and the imaging position of the optical photographing lens assembly corresponding to the lengthwise direction (i.e., the X-axis direction) of the photosensitive area of the image sensor  180 , ImgHY is a maximum distance between the optical axis and the imaging position of the optical photographing lens assembly corresponding to the widthwise direction (i.e., the Y-axis direction) of the photosensitive area of the image sensor  180 , and ImgHD is a maximum distance between the optical axis and the imaging position of the optical photographing lens assembly corresponding to a diagonal direction of the photosensitive area of the image sensor  180 . In  FIG. 23  and  FIG. 29 , ImgHD is a maximum image height of the optical photographing lens assembly (which can be half of a diagonal length of the effective photosensitive area of the image sensor), so the maximum image height direction can refer to the diagonal direction of the photosensitive area of the image sensor  180 . 
     When a paraxial curvature radius of the object-side surface of the first lens element in the maximum image height direction is R1, and a focal length of the optical photographing lens assembly in the maximum image height direction is f, the following condition can be satisfied: −4.5&lt;R1/f&lt;−0.30. Therefore, it is favorable for adjusting the surface shape and refractive power of the first lens element so as to enlarge the field of view and reduce the size of the optical photographing lens assembly. Moreover, the following condition can also be satisfied: −3.5&lt;R1/f&lt;−0.70. Moreover, the following condition can also be satisfied: −2.5&lt;R1/f&lt;−1.0. 
     When the focal length of the optical photographing lens assembly in the maximum image height direction is f, and a composite focal length of the fourth lens element and the fifth lens element in the maximum image height direction is f45, the following condition can be satisfied: 1.9&lt;f45/f. Therefore, it is favorable for the collaboration between the refractive power of the fourth lens element and that of the fifth lens element so as to correct aberrations. Moreover, the following condition can also be satisfied: 2.1&lt;f45/f&lt;5.0. Moreover, the following condition can also be satisfied: 2.3&lt;f45/f&lt;3.6. 
     When a central thickness of the first lens element is CT1, and a central thickness of the fourth lens element is CT4, the following condition can be satisfied: 0.38&lt;CT1/CT4&lt;1.9. Therefore, it is favorable for adjusting the distribution of lens elements so as to obtain a wide-field-of-view configuration. Moreover, the following condition can also be satisfied: 0.44&lt;CT1/CT4&lt;1.6. Moreover, the following condition can also be satisfied: 0.50&lt;CT1/CT4&lt;1.3. Moreover, the following condition can also be satisfied: 0.56&lt;CT1/CT4&lt;1.0. 
     When an Abbe number of the first lens element is V1, an Abbe number of the second lens element is V2, an Abbe number of the third lens element is V3, an Abbe number of the fourth lens element is V4, an Abbe number of the fifth lens element is V5, an Abbe number of the i-th lens element is Vi, a refractive index of the first lens element is N1, a refractive index of the second lens element is N2, a refractive index of the third lens element is N3, a refractive index of the fourth lens element is N4, a refractive index of the fifth lens element is N5, a refractive index of the i-th lens element is Ni, and a minimum value of Vi/Ni is (Vi/Ni)min, the following condition can be satisfied: 7.50&lt;(Vi/Ni)min&lt;11.0, wherein i=1, 2, 3, 4 or 5. Therefore, it is favorable for adjusting the material distribution of lens elements so as to correct aberrations and reduce the size of the optical photographing lens assembly. 
     When the central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, the central thickness of the fourth lens element is CT4, and a central thickness of the fifth lens element is CT5, the following condition can be satisfied: 2.0&lt;(CT2+CT3+CT4+CT5)/CT1&lt;6.5. Therefore, it is favorable for adjusting the distribution of lens elements so as to obtain a wide-field-of-view configuration. Moreover, the following condition can also be satisfied: 3.0&lt;(CT2+CT3+CT4+CT5)/CT1&lt;5.5. 
     When a maximum distance between the optical axis and a boundary of an optically effective area of the object-side surface of the first lens element is Y11, and a maximum distance between the optical axis and a boundary of an optically effective area of the image-side surface of the fifth lens element is Y52, the following condition can be satisfied: 1.0&lt;Y52/Y11&lt;1.7. Therefore, it is favorable for utilizing the space in the optical photographing lens assembly so as to reduce the object-side pupil diameter of the optical photographing lens assembly in a wide-field-of-view configuration. Please refer to  FIG. 28 , which shows a schematic view of Y11 and Y52 according to the 1st embodiment of the present disclosure. In the embodiments of the present disclosure, the maximum distance between the optical axis and the boundary of the optically effective area of one lens surface is the distance between the optical axis and the boundary of the optically effective area of one lens surface in the diagonal direction of the photosensitive area of the image sensor, but the present disclosure is not limited thereto. 
     When the central thickness of the first lens element is CT1, the central thickness of the second lens element is CT2, the central thickness of the third lens element is CT3, the central thickness of the fourth lens element is CT4, and the central thickness of the fifth lens element is CT5, the following condition can be satisfied: 2.9&lt;(CT1+CT2+CT4)/(CT3+CT5)&lt;6.0. Therefore, it is favorable for adjusting the arrangement of lens elements so as to reduce the size of the optical photographing lens assembly. Moreover, the following condition can also be satisfied: 3.3&lt;(CT1+CT2+CT4)/(CT3+CT5)&lt;5.0. 
     When the Abbe number of the third lens element is V3, and the Abbe number of the fifth lens element is V5, the following condition can be satisfied: 20.0&lt;V3+V5&lt;60.0. Therefore, it is favorable for adjusting the material distribution so as to correct aberrations such as chromatic aberration. Moreover, the following condition can also be satisfied: 24.0&lt;V3+V5&lt;50.0. Moreover, the following condition can also be satisfied: 28.0&lt;V3+V5&lt;40.0. 
     When a paraxial curvature radius of the image-side surface of the fourth lens element in the maximum image height direction is R8, and the focal length of the optical photographing lens assembly in the maximum image height direction is f, the following condition can be satisfied: −2.3&lt;R8/f&lt;−0.43. Therefore, it is favorable for adjusting the surface shape and refractive power of the fourth lens element so as to reduce the size of the optical photographing lens assembly and correct aberrations. Moreover, the following condition can also be satisfied: −1.5&lt;R8/f&lt;−0.51. 
     When the focal length of the optical photographing lens assembly in the maximum image height direction is f, and a composite focal length of the first lens element, the second lens element and the third lens element in the maximum image height direction is f123, the following condition can be satisfied: 1.0&lt;f123/f&lt;2.4. Therefore, it is favorable for the first through third lens elements to collaborate with one another so as to reduce the object-side size of the optical photographing lens assembly. Moreover, the following condition can also be satisfied: 1.5&lt;f123/f&lt;2.0. 
     When an axial distance between the object-side surface of the first lens element and the image surface is TL, and the focal length of the optical photographing lens assembly in the maximum image height direction is f, the following condition can be satisfied: 2.2&lt;TL/f&lt;4.0. Therefore, it is favorable for obtaining a balance between the total track length and the field of view of the optical photographing lens assembly. Moreover, the following condition can also be satisfied: 2.5&lt;TL/f&lt;3.6. 
     When an f-number of the optical photographing lens assembly is Fno, the following condition can be satisfied: 1.6&lt;Fno&lt;2.6. Therefore, it is favorable for balancing the illuminance and depth of field. 
     When the Abbe number of the second lens element is V2, the Abbe number of the third lens element is V3, and the Abbe number of the fourth lens element is V4, the following condition can be satisfied: 4.0&lt;(V2+V4)/V3&lt;8.5. Therefore, it is favorable for the collaboration of materials of the second through fourth lens elements so as to correct aberrations such as chromatic aberration. Moreover, the following condition can also be satisfied: 5.0&lt;(V2+V4)/V3&lt;8.0. Moreover, the following condition can also be satisfied: 6.0&lt;(V2+V4)/V3&lt;7.5. 
     When an axial distance between the second lens element and the third lens element is T23, and an axial distance between the third lens element and the fourth lens element is T34, the following condition can be satisfied: 1.0&lt;T34/T23&lt;6.5. Therefore, it is favorable for adjusting the distribution of the lens elements so as to balance the size distribution between the object side and image side of the optical photographing lens assembly. Moreover, the following condition can also be satisfied: 1.3&lt;T34/T23&lt;5.0. 
     When the axial distance between the object-side surface of the first lens element and the image surface is TL, and a maximum image height of the optical photographing lens assembly is ImgH, the following condition can be satisfied: 1.0&lt;TL/ImgH&lt;2.8. Therefore, it is favorable for obtaining a balance between reducing the total track length and enlarging the image surface, and also favorable for adjusting the field of view. Moreover, the following condition can also be satisfied: 1.2&lt;TL/ImgH&lt;2.2. 
     When half of a maximum field of view of the optical photographing lens assembly is HFOV, the following condition can be satisfied: 47.5 degrees&lt;HFOV&lt;70.0 degrees. Therefore, it is favorable for obtaining a wide angle configuration and preventing aberrations, such as distortion, caused by an overly large field of view. Moreover, the following condition can also be satisfied: 55.0 degrees&lt;HFOV&lt;65.0 degrees. 
     When the paraxial curvature radius of the object-side surface of the first lens element in the maximum image height direction is R1, and a focal length of the first lens element in the maximum image height direction is f1, the following condition can be satisfied: 0.10&lt;R1/f1&lt;1.9. Therefore, it is favorable for adjusting the surface shape and refractive power of the first lens element so as to enlarge the field of view and reduce the size of the optical photographing lens assembly. Moreover, the following condition can also be satisfied: 0.35&lt;R1/f1&lt;1.4. 
     When a focal length of the fourth lens element in a maximum image height direction is f4, and the central thickness of the fourth lens element is CT4, the following condition can be satisfied: 1.9&lt;f4/CT4&lt;5.0. Therefore, it is favorable for adjusting the surface shape and refractive power of the fourth lens element so as to reduce the size of the optical photographing lens assembly. Moreover, the following condition can also be satisfied: 2.1&lt;f4/CT4&lt;3.5. 
     When a paraxial curvature radius of the object-side surface of the fifth lens element in the maximum image height direction is R9, and a paraxial curvature radius of the image-side surface of the fifth lens element in the maximum image height direction is R10, the following condition can be satisfied: 1.6&lt;(R9+R10)/(R9−R10)&lt;5.0. Therefore, it is favorable for adjusting the surface shape of the fifth lens element so as to correct off-axis aberrations. Moreover, the following condition can also be satisfied: 2.2&lt;(R9+R10)/(R9−R10)&lt;4.5. 
     When the focal length of the optical photographing lens assembly in the maximum image height direction is f, and a focal length of the fifth lens element in the maximum image height direction is f5, the following condition can be satisfied: −1.0&lt;f/f5&lt;−0.20. Therefore, it is favorable for adjusting the refractive power of the fifth lens element so as to correct aberrations. 
     According to the present disclosure, the aforementioned features and conditions can be utilized in numerous combinations so as to achieve corresponding effects. 
     According to the present disclosure, the lens elements of the optical photographing lens assembly can be made of either glass or plastic material. When the lens elements are made of glass material, the refractive power distribution of the optical photographing lens assembly may be more flexible, and the influence on imaging caused by external environment temperature change may be reduced. The glass lens element can either be made by grinding or molding. When the lens elements are made of plastic material, the manufacturing costs can be effectively reduced. Furthermore, surfaces of each lens element can be arranged to be spherical or aspheric. Spherical lens elements are simple in manufacture. Aspheric lens element design allows more control variables for eliminating aberrations thereof and reducing the required number of lens elements, and the total track length of the optical photographing lens assembly can therefore be effectively shortened. Additionally, the aspheric surfaces may be formed by plastic injection molding or glass molding. 
     According to the present disclosure, when a lens surface is aspheric, it means that the lens surface has an aspheric shape throughout its optically effective area, or a portion(s) thereof. In addition, unless otherwise stated, the aspheric surface in the embodiments refers to an axisymmetric aspheric surface, and the freeform surface in the embodiments refers to a non-axisymmetric aspheric surface. 
     According to the present disclosure, when the features and parameters, such as the field of view, focal length and curvature radius, with axisymmetric properties or non-axisymmetric properties of the optical photographing lens assembly are not specifically defined, these features and parameters can be determined in the maximum image height direction (which can be the diagonal direction of the effective photosensitive area of the image sensor). 
     According to the present disclosure, one or more of the lens elements&#39; material may optionally include an additive which alters the lens elements&#39; transmittance in a specific range of wavelength for a reduction in unwanted stray light or color deviation. For example, the additive may optionally filter out light in the wavelength range of 600 nm to 800 nm to reduce excessive red light and/or near infrared light; or may optionally filter out light in the wavelength range of 350 nm to 450 nm to reduce excessive blue light and/or near ultraviolet light from interfering the final image. The additive may be homogeneously mixed with a plastic material to be used in manufacturing a mixed-material lens element by injection molding. Moreover, the additive may be coated on the lens surfaces to provide the abovementioned effects. 
     According to the present disclosure, each of an object-side surface and an image-side surface has a paraxial region and an off-axis region. The paraxial region refers to the region of the surface where light rays travel close to the optical axis, and the off-axis region refers to the region of the surface away from the paraxial region. Particularly, unless otherwise stated, when the lens element has a convex surface, it indicates that the surface is convex in the paraxial region thereof; when the lens element has a concave surface, it indicates that the surface is concave in the paraxial region thereof. Moreover, when a region of refractive power or focus of a lens element is not defined, it indicates that the region of refractive power or focus of the lens element is in the paraxial region thereof. 
     According to the present disclosure, a critical point is a non-axial point of the lens surface where its tangent is perpendicular to the optical axis. 
     According to the present disclosure, the image surface of the optical photographing lens assembly, based on the corresponding image sensor, can be flat or curved, especially a curved surface being concave facing towards the object side of the optical photographing lens assembly. 
     According to the present disclosure, an image correction unit, such as a field flattener, can be optionally disposed between the lens element closest to the image side of the optical photographing lens assembly along the optical path and the image surface for correction of aberrations such as field curvature. The optical properties of the image correction unit, such as curvature, thickness, index of refraction, position and surface shape (convex or concave surface with spherical, aspheric, diffractive or Fresnel types), can be adjusted according to the design of the image capturing unit. In general, a preferable image correction unit is, for example, a thin transparent element having a concave object-side surface and a planar image-side surface, and the thin transparent element is disposed near the image surface. 
     According to the present disclosure, at least one light-folding element, such as a prism or a mirror, can be optionally disposed between an imaged object and the image surface on the imaging optical path, such that the optical photographing lens assembly can be more flexible in space arrangement, and therefore the dimensions of an electronic device is not restricted by the total track length of the optical photographing lens assembly. Specifically, please refer to  FIG. 30  and  FIG. 31 .  FIG. 30  shows a schematic view of a configuration of a light-folding element in an optical photographing lens assembly according to one embodiment of the present disclosure, and  FIG. 31  shows a schematic view of another configuration of a light-folding element in an optical photographing lens assembly according to one embodiment of the present disclosure. In  FIG. 30  and  FIG. 31 , the optical photographing lens assembly can have, in order from an imaged object (not shown in the figures) to an image surface IM along an optical path, a first optical axis OA 1 , a light-folding element LF and a second optical axis OA 2 . The light-folding element LF can be disposed between the imaged object and a lens group LG of the optical photographing lens assembly as shown in  FIG. 30  or disposed between a lens group LG of the optical photographing lens assembly and the image surface IM as shown in  FIG. 31 . Furthermore, please refer to  FIG. 32 , which shows a schematic view of a configuration of two light-folding elements in an optical photographing lens assembly according to one embodiment of the present disclosure. In  FIG. 32 , the optical photographing lens assembly can have, in order from an imaged object (not shown in the figure) to an image surface IM along an optical path, a first optical axis OA 1 , a first light-folding element LF 1 , a second optical axis OA 2 , a second light-folding element LF 2  and a third optical axis OA 3 . The first light-folding element LF 1  is disposed between the imaged object and a lens group LG of the optical photographing lens assembly, the second light-folding element LF 2  is disposed between the lens group LG of the optical photographing lens assembly and the image surface IM. The optical photographing lens assembly can be optionally provided with three or more light-folding elements, and the present disclosure is not limited to the type, amount and position of the light-folding elements of the embodiments disclosed in the aforementioned figures. 
     According to the present disclosure, the optical photographing lens assembly can include at least one stop, such as an aperture stop, a glare stop or a field stop. Said glare stop or said field stop is set for eliminating the stray light and thereby improving image quality thereof. 
     According to the present disclosure, an aperture stop can be configured as a front stop or a middle stop. A front stop disposed between an imaged object and the first lens element can provide a longer distance between an exit pupil of the optical photographing lens assembly and the image surface to produce a telecentric effect, and thereby improves the image-sensing efficiency of an image sensor (for example, CCD or CMOS). A middle stop disposed between the first lens element and the image surface is favorable for enlarging the viewing angle of the optical photographing lens assembly and thereby provides a wider field of view for the same. 
     According to the present disclosure, the optical photographing lens assembly can include an aperture control unit. The aperture control unit may be a mechanical component or a light modulator, which can control the size and shape of the aperture through electricity or electrical signals. The mechanical component can include a movable member, such as a blade assembly or a light shielding sheet. The light modulator can include a shielding element, such as a filter, an electrochromic material or a liquid-crystal layer. The aperture control unit controls the amount of incident light or exposure time to enhance the capability of image quality adjustment. In addition, the aperture control unit can be the aperture stop of the present disclosure, which changes the f-number to obtain different image effects, such as the depth of field or lens speed. 
     According to the above description of the present disclosure, the following specific embodiments are provided for further explanation. 
     1st Embodiment 
       FIG. 1  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 1st embodiment of the present disclosure.  FIG. 2  shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 1st embodiment. In  FIG. 1 , the image capturing unit includes the optical photographing lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor  180 . The optical photographing lens assembly includes, in order from an object side to an image side along an optical path, a first lens element  110 , an aperture stop  100 , a second lens element  120 , a third lens element  130 , a fourth lens element  140 , a fifth lens element  150 , a filter  160  and an image surface  170 . The optical photographing lens assembly includes five lens elements ( 110 ,  120 ,  130 ,  140  and  150 ) with no additional lens element disposed between each of the adjacent five lens elements. 
     The first lens element  110  with negative refractive power has an object-side surface  111  being concave in a paraxial region thereof and an image-side surface  112  being concave in a paraxial region thereof. The first lens element  110  is made of plastic material and has the object-side surface  111  being a freeform surface and the image-side surface  112  being aspheric. The object-side surface  111  of the first lens element  110  has one critical point in an off-axis region thereof and in a maximum image height direction. 
     The second lens element  120  with positive refractive power has an object-side surface  121  being convex in a paraxial region thereof and an image-side surface  122  being convex in a paraxial region thereof. The second lens element  120  is made of plastic material and has the object-side surface  121  and the image-side surface  122  being both aspheric. 
     The third lens element  130  with negative refractive power has an object-side surface  131  being concave in a paraxial region thereof and an image-side surface  132  being concave in a paraxial region thereof. The third lens element  130  is made of plastic material and has the object-side surface  131  and the image-side surface  132  being both aspheric. 
     The fourth lens element  140  with positive refractive power has an object-side surface  141  being convex in a paraxial region thereof and an image-side surface  142  being convex in a paraxial region thereof. The fourth lens element  140  is made of plastic material and has the object-side surface  141  and the image-side surface  142  being both aspheric. 
     The fifth lens element  150  with negative refractive power has an object-side surface  151  being convex in a paraxial region thereof and an image-side surface  152  being concave in a paraxial region thereof. The fifth lens element  150  is made of plastic material and has the object-side surface  151  being aspheric and the image-side surface  152  being a freeform surface. The object-side surface  151  of the fifth lens element  150  has one critical point in an off-axis region thereof and in the maximum image height direction. The image-side surface  152  of the fifth lens element  150  has one critical point in an off-axis region thereof and in the maximum image height direction. 
     The filter  160  is made of glass material and located between the fifth lens element  150  and the image surface  170 , and will not affect the focal length of the optical photographing lens assembly. The image sensor  180  is disposed on or near the image surface  170  of the optical photographing lens assembly. 
     In this embodiment, the maximum image height direction corresponds to a diagonal direction D of a photosensitive area of the image sensor  180 , but the present disclosure is not limited thereto. 
     The equation of the (axisymmetric) aspheric surface profiles of the aforementioned aspheric lens elements of the 1st embodiment is expressed as follows: 
     
       
         
           
             
               
                 z 
                 ⁡ 
                 ( 
                 r 
                 ) 
               
               = 
               
                 
                   
                     
                       r 
                       2 
                     
                     R 
                   
                   
                     1 
                     + 
                     
                       
                         1 
                         - 
                         
                           
                             ( 
                             
                               1 
                               + 
                               k 
                             
                             ) 
                           
                           ⁢ 
                           
                             
                               ( 
                               
                                 r 
                                 R 
                               
                               ) 
                             
                             2 
                           
                         
                       
                     
                   
                 
                 + 
                 
                   
                     ∑ 
                     i 
                   
                   
                     
                       ( 
                       
                         A 
                         ⁢ 
                         i 
                       
                       ) 
                     
                     ⁢ 
                     
                       r 
                       i 
                     
                   
                 
               
             
             , 
           
         
       
     
     where, 
     z is a displacement in parallel with an optical axis from an intersection point between the aspheric surface and the optical axis to a point at a distance of r from the optical axis on the aspheric surface; 
     r is a vertical distance from the point on the aspheric surface to the optical axis; 
     R is the curvature radius in a paraxial region of the aspheric surface; 
     k is the conic coefficient; and 
     Ai is the i-th aspheric coefficient, and in the embodiments, i may be, but is not limited to, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24. 
     The equation of the freeform surface profiles of the aforementioned freeform lens elements of the 1st embodiment is expressed as follows: 
     
       
         
           
             
               
                 z 
                 ⁡ 
                 ( 
                 
                   x 
                   , 
                   y 
                 
                 ) 
               
               = 
               
                 
                   
                     
                       
                         x 
                         2 
                       
                       
                         R 
                         ⁢ 
                         x 
                       
                     
                     + 
                     
                       
                         y 
                         2 
                       
                       
                         R 
                         ⁢ 
                         y 
                       
                     
                   
                   
                     1 
                     + 
                     
                       
                         1 
                         - 
                         
                           
                             ( 
                             
                               1 
                               + 
                               kx 
                             
                             ) 
                           
                           ⁢ 
                           
                             
                               ( 
                               
                                 x 
                                 
                                   R 
                                   ⁢ 
                                   x 
                                 
                               
                               ) 
                             
                             2 
                           
                         
                         - 
                         
                           
                             ( 
                             
                               1 
                               + 
                               ky 
                             
                             ) 
                           
                           ⁢ 
                           
                             
                               ( 
                               
                                 y 
                                 
                                   R 
                                   ⁢ 
                                   y 
                                 
                               
                               ) 
                             
                             2 
                           
                         
                       
                     
                   
                 
                 + 
                 
                   
                     ∑ 
                     i 
                   
                   
                     
                       ( 
                       
                         
                           
                             
                               Axi 
                               - 
                               Ayi 
                             
                             2 
                           
                           ⁢ 
                           
                             ( 
                             
                               
                                 2 
                                 ⁢ 
                                 
                                   
                                     x 
                                     2 
                                   
                                   
                                     
                                       x 
                                       2 
                                     
                                     + 
                                     
                                       y 
                                       2 
                                     
                                   
                                 
                               
                               - 
                               1 
                             
                             ) 
                           
                         
                         + 
                         
                           
                             Axi 
                             + 
                             Ayi 
                           
                           2 
                         
                       
                       ) 
                     
                     ⁢ 
                     
                       
                         ( 
                         
                           r 
                           ⁡ 
                           ( 
                           
                             x 
                             , 
                             y 
                           
                           ) 
                         
                         ) 
                       
                       i 
                     
                   
                 
               
             
             , 
           
         
       
     
     where, 
     z is a displacement in parallel with the optical axis from an intersection point between the freeform surface and the optical axis to a point at (x, y) on the freeform surface; 
     r(x, y) is a vertical distance from the point on the freeform surface to the optical axis, and r(x, y)=sqrt(x 2 +y 2 ); 
     x is the x-coordinate of the point on the freeform surface; 
     y is the y-coordinate of the point on the freeform surface; 
     Rx is the paraxial curvature radius of the freeform surface in the X-axis direction; Ry is the paraxial curvature radius of the freeform surface in the Y-axis direction; 
     kx is the conic coefficient in the X-axis direction; 
     ky is the conic coefficient in the Y-axis direction; 
     Axi is the i-th freeform coefficient in the X-axis direction, and in the embodiments, i may be, but is not limited to, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 and 26; and 
     Ayi is the i-th freeform coefficient in the Y-axis direction, and in the embodiments, i may be, but is not limited to, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 and 26. 
     In this and the following embodiments, the equation of the freeform surface profiles applied to the design of the freeform lens elements are not intended to limit the present disclosure. In other configurations, other equations of the freeform surface profiles, such as anamorphic asphere equation, Zernike or x-y polynomials, can also be applied to the design of freeform lens elements according to actual requirements. 
     In this embodiment, a direction of light travelling into the image surface  170  on the optical axis is the positive Z-axis direction, a direction corresponding to a lengthwise direction of the photosensitive area of the image sensor  180  is the X-axis direction, a direction corresponding to a widthwise direction of the photosensitive area of the image sensor  180  is the Y-axis direction, and a direction corresponding to the diagonal direction of the photosensitive area of the image sensor  180  is the D direction, but the present disclosure is not limited thereto. 
     In the optical photographing lens assembly of the image capturing unit according to the 1st embodiment, when a focal length of the optical photographing lens assembly corresponding to the diagonal direction D of the photosensitive area of the image sensor  180  is fD, a focal length of the optical photographing lens assembly corresponding to the lengthwise direction (the X-axis direction) of the photosensitive area of the image sensor  180  is fX, and a focal length of the optical photographing lens assembly corresponding to the widthwise direction (the Y-axis direction) of the photosensitive area of the image sensor  180  is fY, these parameters have the following values: fD=1.76 millimeters (mm), fX=1.76 mm, fY=1.76 mm. 
     When an f-number of the optical photographing lens assembly is Fno, the following condition is satisfied: Fno=2.32. 
     When half of a maximum field of view of the optical photographing lens assembly corresponding to the diagonal direction D of the photosensitive area of the image sensor  180  is HFOVD, half of a maximum field of view of the optical photographing lens assembly corresponding to the lengthwise direction of the photosensitive area of the image sensor  180  is HFOVX, and half of a maximum field of view of the optical photographing lens assembly corresponding to the widthwise direction of the photosensitive area of the image sensor  180  is HFOVY, these parameters have the following values: HFOVD=59.3 degrees (deg.), HFOVX=53.4 deg., HFOVY=44.4 deg. 
     When a maximum distance between the optical axis and the imaging position of the optical photographing lens assembly corresponding to the diagonal direction D of the photosensitive area of the image sensor  180  is ImgHD, a maximum distance between the optical axis and the imaging position of the optical photographing lens assembly corresponding to the lengthwise direction of the photosensitive area of the image sensor  180  is ImgHX, and a maximum distance between the optical axis and the imaging position of the optical photographing lens assembly corresponding to the widthwise direction of the photosensitive area of the image sensor  180  is ImgHY, these parameters have the following values: ImgHD=2.93 mm, ImgHX=2.36 mm, ImgHY=1.75 mm. 
     When an Abbe number of the second lens element  120  is V2, an Abbe number of the third lens element  130  is V3, and an Abbe number of the fourth lens element  140  is V4, the following condition is satisfied: (V2+V4)/V3=6.07. 
     When an Abbe number of the first lens element  110  is V1, the Abbe number of the second lens element  120  is V2, the Abbe number of the third lens element  130  is V3, the Abbe number of the fourth lens element  140  is V4, an Abbe number of the fifth lens element  150  is V5, an Abbe number of the i-th lens element is Vi, a refractive index of the first lens element  110  is N1, a refractive index of the second lens element  120  is N2, a refractive index of the third lens element  130  is N3, a refractive index of the fourth lens element  140  is N4, a refractive index of the fifth lens element  150  is N5, a refractive index of the i-th lens element is Ni, and a minimum value of Vi/Ni is (Vi/Ni)min, the following condition is satisfied: (Vi/Ni)min=10.98, wherein i=1, 2, 3, 4 or 5. In this embodiment, among the first lens element  110  through the fifth lens element  150 , a ratio of the Abbe number to the refractive index of the third lens element  130  and a ratio of the Abbe number to the refractive index of the fifth lens element  150  are the same and both smaller than ratios of Abbe number to refractive index of the other lens elements, and (Vi/Ni)min is equal to the ratio of the Abbe number to the refractive index of the third lens element  130  and the ratio of the Abbe number to the refractive index of the fifth lens element  150 . 
     When the Abbe number of the third lens element  130  is V3, and the Abbe number of the fifth lens element  150  is V5, the following condition is satisfied: V3+V5=36.9. 
     When a central thickness of the first lens element  110  is CT1, a central thickness of the second lens element  120  is CT2, a central thickness of the third lens element  130  is CT3, a central thickness of the fourth lens element  140  is CT4, and a central thickness of the fifth lens element  150  is CT5, the following condition is satisfied: (CT1+CT2+CT4)/(CT3+CT5)=3.95. 
     When the central thickness of the first lens element  110  is CT1, the central thickness of the second lens element  120  is CT2, the central thickness of the third lens element  130  is CT3, the central thickness of the fourth lens element  140  is CT4, and the central thickness of the fifth lens element  150  is CT5, the following condition is satisfied: (CT2+CT3+CT4+CT5)/CT1=3.43. 
     When the central thickness of the first lens element  110  is CT1, and the central thickness of the fourth lens element  140  is CT4, the following condition is satisfied: CT1/CT4=0.86. 
     When an axial distance between the second lens element  120  and the third lens element  130  is T23, and an axial distance between the third lens element  130  and the fourth lens element  140  is T34, the following condition is satisfied: T34/T23=1.57. In this embodiment, an axial distance between two adjacent lens elements is a distance in a paraxial region between two adjacent lens surfaces of the two adjacent lens elements. 
     When an axial distance between the object-side surface  111  of the first lens element  110  and the image surface  170  is TL, and the focal length of the optical photographing lens assembly in the maximum image height direction is f, the following condition is satisfied: TL/f=3.10. In this embodiment, the optical photographing lens assembly has the maximum image height in the diagonal direction D of the photosensitive area of the image sensor  180 , and the focal length of the optical photographing lens assembly in the maximum image height direction (f) refers to the focal length of the optical photographing lens assembly corresponding to the diagonal direction D of the photosensitive area of the image sensor  180  (fD). 
     When the axial distance between the object-side surface  111  of the first lens element  110  and the image surface  170  is TL, and a maximum image height of the optical photographing lens assembly is ImgH, the following condition is satisfied: TL/ImgH=1.86. In this embodiment, the maximum image height of the optical photographing lens assembly (ImgH) refers to the maximum distance between the optical axis and the imaging position of the optical photographing lens assembly corresponding to the diagonal direction D of the photosensitive area of the image sensor  180  (ImgHD). 
     When a paraxial curvature radius of the object-side surface  151  of the fifth lens element  150  in the maximum image height direction is R9, and a paraxial curvature radius of the image-side surface  152  of the fifth lens element  150  in the maximum image height direction is R10, the following condition is satisfied: (R9+R10)/(R9−R10)=2.96. 
     When a paraxial curvature radius of the object-side surface  111  of the first lens element  110  in the maximum image height direction is R1, and the focal length of the optical photographing lens assembly in the maximum image height direction is f, the following condition is satisfied: R1/f=−1.51. 
     When the paraxial curvature radius of the object-side surface  111  of the first lens element  110  in the maximum image height direction is R1, and a focal length of the first lens element  110  in the maximum image height direction is f1, the following condition is satisfied: R1/f1=0.74. 
     When a paraxial curvature radius of the image-side surface  142  of the fourth lens element  140  in the maximum image height direction is R8, and the focal length of the optical photographing lens assembly in the maximum image height direction is f, the following condition is satisfied: R8/f=−0.62. 
     When the focal length of the optical photographing lens assembly in the maximum image height direction is f, and a focal length of the fifth lens element  150  in the maximum image height direction is f5, the following condition is satisfied: f/f5=−0.79. 
     When the focal length of the optical photographing lens assembly in the maximum image height direction is f, and a composite focal length of the first lens element  110 , the second lens element  120  and the third lens element  130  in the maximum image height direction is f123, the following condition is satisfied: f123/f=1.82. 
     When a focal length of the fourth lens element  140  in a maximum image height direction is f4, and the central thickness of the fourth lens element  140  is CT4, the following condition is satisfied: f4/CT4=2.47. 
     When the focal length of the optical photographing lens assembly in the maximum image height direction is f, and a composite focal length of the fourth lens element  140  and the fifth lens element  150  in the maximum image height direction is f45, the following condition is satisfied: f45/f=2.80. 
     When half of a maximum field of view of the optical photographing lens assembly is HFOV, the following condition is satisfied: HFOV=59.3 degrees. In this embodiment, half of the maximum field of view of the optical photographing lens assembly (HFOV) refers to half of the maximum field of view of the optical photographing lens assembly corresponding to the diagonal direction D of the photosensitive area of the image sensor  180  (HFOVD). 
     When a maximum distance between the optical axis and a boundary of an optically effective area of the object-side surface  111  of the first lens element  110  is Y11, and a maximum distance between the optical axis and a boundary of an optically effective area of the image-side surface  152  of the fifth lens element  150  is Y52, the following condition is satisfied: Y52/Y11=1.32. 
     When a minimum value among distances between the optical axis and a boundary of an optically effective area of one lens surface is Ymin, a displacement in parallel with the optical axis from an intersection point between the lens surface and the optical axis to a position at a distance of Ymin from the optical axis on the lens surface is SAG, a maximum value among all the displacements SAG is SAG_MAX, a minimum value among all the displacements SAG is SAG_MIN, and an absolute difference between SAG_MAX and SAG_MIN is |dSAG|max, the object-side surface  111  of the first lens element  110  satisfies the following condition: |dSAG|max=0.88 um; and the image-side surface  152  of the fifth lens element  150  satisfies the following condition: |dSAG|max=14.89 um. 
     When the absolute difference between SAG_MAX and SAG_MIN is |dSAG|max, and a central thickness of one freeform lens element is CTF, the object-side surface  111  of the first lens element  110  satisfies the following condition: |dSAG|max/CTF=1.33E-03, and the image-side surface  152  of the fifth lens element  150  satisfies the following condition: |dSAG|max/CTF=4.46E-02. 
     The detailed optical data of the 1st embodiment are shown in Table 1, the aspheric surface data are shown in Table 2 and the freeform surface data are shown in Table 3 below. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 1st Embodiment 
               
               
                 fD = 1.76 mm, fX = 1.76 mm, fY = 1.76 mm, Fno = 2.32 
               
               
                 HFOVD = 59.3 deg., HFOVX = 53.4 deg., HFOVY = 44.4 deg. 
               
               
                 ImgHD = 2.93 mm, ImgHX = 2.36 mm, ImgHY = 1.75 mm 
               
            
           
           
               
               
               
               
            
               
                   
                 Curvature Radius 
                   
                 Focal Length 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Surface # 
                   
                 (Y-dir.) 
                 (X-dir.) 
                   
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 (Y-dir.) 
                 (X-dir.) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                 Lens 1 
                 −2.6677 
                 −2.6646 
                 (FFS) 
                 0.665 
                 Plastic 
                 1.545 
                 56.1 
                 −3.62 
                 −3.62 
               
               
                 2 
                   
                 8.2534 
                   
                 (ASP) 
                 0.852 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 3 
                 Ape. Stop 
                 Plano 
                 −0.039  
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 4 
                 Lens 2 
                 2.3809 
                   
                 (ASP) 
                 0.907 
                 Plastic 
                 1.544 
                 56.0 
                 1.92 
                   
               
               
                 5 
                   
                 −1.6183 
                   
                 (ASP) 
                 0.216 
               
               
                 6 
                 Lens 3 
                 −212.3142 
                   
                 (ASP) 
                 0.260 
                 Plastic 
                 1.679 
                 18.4 
                 −7.64 
               
               
                 7 
                   
                 5.3227 
                   
                 (ASP) 
                 0.339 
               
               
                 8 
                 Lens 4 
                 17.2830 
                   
                 (ASP) 
                 0.777 
                 Plastic 
                 1.544 
                 56.0 
                 1.92 
               
               
                 9 
                   
                 −1.0921 
                   
                 (ASP) 
                 0.020 
               
               
                 10 
                 Lens 5 
                 1.1901 
                   
                 (ASP) 
                 0.334 
                 Plastic 
                 1.679 
                 18.4 
                 −2.22 
                 −2.22 
               
               
                 11 
                   
                 0.5892 
                 0.5899 
                 (FFS) 
                 0.511 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 12 
                 Filter 
                 Plano 
                 0.210 
                 Glass 
                 1.517 
                 64.2 
                 — 
                   
               
               
                 13 
                   
                 Plano 
                 0.410 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm (d-line). 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 Surface # 
                 2 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k= 
                  6.63346E+00 
                  0.00000E+00 
                  2.24076E−01 
                 −9.90000E+01 
               
               
                 A4= 
                 6.012126E−01 
                 −5.495774E−02 
                 −2.485100E−01 
                 −3.540326E−01  
               
               
                 A6= 
                 −2.349906E+00  
                  6.281119E−01 
                  2.601063E−01 
                 1.063316E−01 
               
               
                 A8= 
                 1.719376E+01 
                 −1.692190E+01 
                 −3.664628E−01 
                 8.873563E−01 
               
               
                 A10= 
                 −7.957765E+01  
                  2.043021E+02 
                 −8.818583E−01 
                 −3.759282E+00  
               
               
                 A12= 
                 2.267024E+02 
                 −1.493594E+03 
                  1.462292E+00 
                 6.853926E+00 
               
               
                 A14= 
                 −3.990882E+02  
                  6.587888E+03 
                  4.630695E−02 
                 −7.680991E+00  
               
               
                 A16= 
                 4.259016E+02 
                 −1.705999E+04 
                 −1.181290E+00 
                 3.551037E+00 
               
               
                 A18= 
                 −2.519085E+02  
                  2.361338E+04 
                 — 
                 — 
               
               
                 A20= 
                 5.790548E+01 
                 −1.337107E+04 
                 — 
                 — 
               
               
                 A22= 
                 1.075882E+01 
                 — 
                 — 
                 — 
               
               
                 A24= 
                 −5.706941E+00  
                 — 
                 — 
                 — 
               
               
                   
               
               
                 Surface # 
                 7 
                 8 
                 9 
                 10 
               
               
                   
               
               
                 k= 
                  4.68789E+00 
                  0.00000E+00 
                  −7.43298E+00 
                  −9.04568E+00 
               
               
                 A4= 
                 −1.022495E−01 
                 3.284378E−01 
                  2.407380E−01 
                 −3.171420E−02 
               
               
                 A6= 
                 −1.639047E−01 
                 −5.800685E−01  
                 −2.999209E−01 
                 −1.649166E−01 
               
               
                 A8= 
                  5.635294E−01 
                 6.362284E−01 
                  2.675461E−01 
                  1.319010E−01 
               
               
                 A10= 
                 −4.590784E−01 
                 −5.176996E−01  
                 −2.208042E−01 
                 −3.354498E−02 
               
               
                 A12= 
                 −2.821177E−01 
                 3.080480E−01 
                  1.357114E−01 
                 −6.440382E−03 
               
               
                 A14= 
                  6.788532E−01 
                 −1.242969E−01  
                 −5.218690E−02 
                  6.752361E−03 
               
               
                 A16= 
                 −3.982331E−01 
                 3.123281E−02 
                  1.188905E−02 
                 −1.993577E−03 
               
               
                 A18= 
                  8.013122E−02 
                 −4.322786E−03  
                 −1.526041E−03 
                  2.996921E−04 
               
               
                 A20= 
                 — 
                 2.450763E−04 
                  9.808104E−05 
                 −2.311243E−05 
               
               
                 A22= 
                 — 
                 — 
                 −2.281799E−06 
                  7.214728E−07 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Freeform Coefficients 
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface # 
                 1 
                 11 
                 Surface # 
                 1 
                 11 
               
               
                   
               
               
                 kx= 
                  0.00000E+00 
                  −4.28887E+00 
                 ky= 
                  −1.02499E−06 
                  −4.23853E+00 
               
               
                 Ax4= 
                  3.215950E−01 
                 −1.317795E−01 
                 Ay4= 
                  3.217278E−01 
                 −1.260829E−01 
               
               
                 Ax6= 
                 −3.275293E−01 
                  1.198981E−01 
                 Ay6= 
                 −3.276646E−01 
                  1.147151E−01 
               
               
                 Ax8= 
                  3.546100E−01 
                 −1.723913E−01 
                 Ay8= 
                  3.547564E−01 
                 −1.649391E−01 
               
               
                 Ax10= 
                 −3.201050E−01 
                  1.758572E−01 
                 Ay10= 
                 −3.202372E−01 
                  1.682552E−01 
               
               
                 Ax12= 
                  2.182247E−01 
                 −1.118793E−01 
                 Ay12= 
                  2.183148E−01 
                 −1.070430E−01 
               
               
                 Ax14= 
                 −1.052810E−01 
                  4.618967E−02 
                 Ay14= 
                 −1.053245E−01 
                  4.419298E−02 
               
               
                 Ax16= 
                  3.430992E−02 
                 −1.274935E−02 
                 Ay16= 
                  3.432409E−02 
                 −1.219822E−02 
               
               
                 Ax18= 
                 −7.134279E−03 
                  2.370854E−03 
                 Ay18= 
                 −7.137225E−03 
                  2.268366E−03 
               
               
                 Ax20= 
                  8.514545E−04 
                 −2.926252E−04 
                 Ay20= 
                  8.518061E−04 
                 −2.799756E−04 
               
               
                 Ax22= 
                 −4.433496E−05 
                  2.291637E−05 
                 Ay22= 
                 −4.435326E−05 
                  2.192574E−05 
               
               
                 Ax24= 
                 — 
                 −1.027625E−06 
                 Ay24= 
                 — 
                 −9.832030E−07 
               
               
                 Ax26= 
                 — 
                  2.002842E−08 
                 Ay26= 
                 — 
                  1.916263E−08 
               
               
                   
               
            
           
         
       
     
     In Table 1, the curvature radius, the thickness and the focal length are shown in millimeters (mm). Surface numbers 0-14 represent the surfaces sequentially arranged from the object side to the image side along the optical axis. The curvature radius and the focal length in the X-axis direction (X-dir.) are given in Table 1 only when the curvature radius and the focal length of the surface in the X-axis direction may be different from that in the Y-axis direction (Y-dir.). In Table 2, k represents the conic coefficient of the equation of the aspheric surface profiles. A4-A24 represent the axisymmetric aspheric coefficients ranging from the 4th order to the 24th order. In Table 3, kx represents the conic coefficient of the equation of the freeform surface profiles in the X-axis direction, and ky represents the conic coefficient of the equation of the freeform surface profiles in the Y-axis direction. Ax4-Ax26 represent the freeform coefficients ranging from the 4th order to the 26th order in the X-axis direction, and Ay4-Ay26 represent the freeform coefficients ranging from the 4th order to the 26th order in the Y-axis direction. The tables presented below for each embodiment are the corresponding schematic parameter and aberration curves, and the definitions of the tables are the same as Table 1, Table 2 and Table 3 of the 1st embodiment. Therefore, an explanation in this regard will not be provided again. 
     2nd Embodiment 
       FIG. 3  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 2nd embodiment of the present disclosure.  FIG. 4  shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 2nd embodiment. In  FIG. 3 , the image capturing unit includes the optical photographing lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor  280 . The optical photographing lens assembly includes, in order from an object side to an image side along an optical path, a first lens element  210 , an aperture stop  200 , a second lens element  220 , a third lens element  230 , a fourth lens element  240 , a fifth lens element  250 , a filter  260  and an image surface  270 . The optical photographing lens assembly includes five lens elements ( 210 ,  220 ,  230 ,  240  and  250 ) with no additional lens element disposed between each of the adjacent five lens elements. 
     The first lens element  210  with negative refractive power has an object-side surface  211  being concave in a paraxial region thereof and an image-side surface  212  being concave in a paraxial region thereof. The first lens element  210  is made of plastic material and has the object-side surface  211  and the image-side surface  212  being both aspheric. The object-side surface  211  of the first lens element  210  has one critical point in an off-axis region thereof and in a maximum image height direction. 
     The second lens element  220  with positive refractive power has an object-side surface  221  being convex in a paraxial region thereof and an image-side surface  222  being convex in a paraxial region thereof. The second lens element  220  is made of plastic material and has the object-side surface  221  and the image-side surface  222  being both aspheric. 
     The third lens element  230  with negative refractive power has an object-side surface  231  being convex in a paraxial region thereof and an image-side surface  232  being concave in a paraxial region thereof. The third lens element  230  is made of plastic material and has the object-side surface  231  and the image-side surface  232  being both aspheric. 
     The fourth lens element  240  with positive refractive power has an object-side surface  241  being convex in a paraxial region thereof and an image-side surface  242  being convex in a paraxial region thereof. The fourth lens element  240  is made of plastic material and has the object-side surface  241  and the image-side surface  242  being both aspheric. 
     The fifth lens element  250  with negative refractive power has an object-side surface  251  being convex in a paraxial region thereof and an image-side surface  252  being concave in a paraxial region thereof. The fifth lens element  250  is made of plastic material and has the object-side surface  251  being aspheric and the image-side surface  252  being a freeform surface. The object-side surface  251  of the fifth lens element  250  has one critical point in an off-axis region thereof and in the maximum image height direction. The image-side surface  252  of the fifth lens element  250  has one critical point in an off-axis region thereof and in the maximum image height direction. 
     The filter  260  is made of glass material and located between the fifth lens element  250  and the image surface  270 , and will not affect the focal length of the optical photographing lens assembly. The image sensor  280  is disposed on or near the image surface  270  of the optical photographing lens assembly. 
     In this embodiment, the maximum image height direction corresponds to a diagonal direction D of a photosensitive area of the image sensor  280 . 
     In this embodiment, the image-side surface  252  of the fifth lens element  250  satisfies the following conditions: |dSAG|max=3.27 um; and |dSAG|max/CTF=1.06E-02. 
     The detailed optical data of the 2nd embodiment are shown in Table 4, the aspheric surface data are shown in Table 5 and the freeform surface data are shown in Table 6 below. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 2nd Embodiment 
               
               
                 fD = 1.80 mm, fX = 1.80 mm, fY = 1.80 mm, Fno = 2.40 
               
               
                 HFOVD = 59.9 deg., HFOVX = 52.6 deg., HFOVY = 44.1 deg. 
               
               
                 ImgHD = 2.93 mm, ImgHX = 2.36 mm, ImgHY = 1.75 mm 
               
            
           
           
               
               
               
               
            
               
                   
                 Curvature Radius 
                   
                 Focal Length 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Surface # 
                   
                 (Y-dir.) 
                 (X-dir.) 
                   
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 (Y-dir.) 
                 (X-dir.) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                 Lens 1 
                 −3.5905 
                   
                 (ASP) 
                 0.532 
                 Plastic 
                 1.545 
                 56.1 
                 −4.11 
                   
               
               
                 2 
                   
                 6.2525 
                   
                 (ASP) 
                 0.892 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 3 
                 Ape. Stop 
                 Plano 
                 −0.002  
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 4 
                 Lens 2 
                 3.6685 
                   
                 (ASP) 
                 0.803 
                 Plastic 
                 1.545 
                 56.1 
                 1.89 
                   
               
               
                 5 
                   
                 −1.3209 
                   
                 (ASP) 
                 0.170 
               
               
                 6 
                 Lens 3 
                 3.8336 
                   
                 (ASP) 
                 0.230 
                 Plastic 
                 1.686 
                 18.4 
                 −6.14 
               
               
                 7 
                   
                 1.9581 
                   
                 (ASP) 
                 0.488 
               
               
                 8 
                 Lens 4 
                 9992.5080 
                   
                 (ASP) 
                 0.690 
                 Plastic 
                 1.545 
                 56.1 
                 2.05 
               
               
                 9 
                   
                 −1.1156 
                   
                 (ASP) 
                 0.030 
               
               
                 10 
                 Lens 5 
                 1.0395 
                   
                 (ASP) 
                 0.310 
                 Plastic 
                 1.660 
                 20.4 
                 −2.62 
                 −2.62 
               
               
                 11 
                   
                 0.5724 
                 0.5724 
                 (FFS) 
                 0.501 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 12 
                 Filter 
                 Plano 
                 0.210 
                 Glass 
                 1.517 
                 64.2 
                 — 
                   
               
               
                 13 
                   
                 Plano 
                 0.435 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm (d-line). 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 5 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface # 
                 1 
                 2 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k= 
                  0.00000E+00 
                  8.64447E+00 
                  −1.66746E+01 
                  5.25344E−01 
                  2.07722E+00 
               
               
                 A4= 
                  3.119563E−01 
                 5.735605E−01 
                 −6.886130E−02 
                 −1.793509E−01 
                 −4.361121E−01 
               
               
                 A6= 
                 −3.016952E−01 
                 −2.050908E+00  
                 −3.393906E−01 
                 −5.792383E−02 
                  7.241191E−01 
               
               
                 A8= 
                  3.297453E−01 
                 1.507263E+01 
                  9.572436E−01 
                  2.015328E+00 
                 −1.742018E+00 
               
               
                 A10= 
                 −3.248170E−01 
                 −7.207347E+01  
                 −5.446880E+00 
                 −1.083423E+01 
                  3.372963E+00 
               
               
                 A12= 
                  2.607876E−01 
                 2.200937E+02 
                  5.380449E+00 
                  2.445338E+01 
                 −4.835859E+00 
               
               
                 A14= 
                 −1.549939E−01 
                 −4.343553E+02  
                 — 
                 −2.705640E+01 
                  3.828648E+00 
               
               
                 A16= 
                  6.355415E−02 
                 5.565740E+02 
                 — 
                  1.129481E+01 
                 −1.152293E+00 
               
               
                 A18= 
                 −1.675296E−02 
                 −4.539848E+02  
                 — 
                 — 
                 — 
               
               
                 A20= 
                  2.533162E−03 
                 2.241443E+02 
                 — 
                 — 
                 — 
               
               
                 A22= 
                 −1.665068E−04 
                 −6.025687E+01  
                 — 
                 — 
                 — 
               
               
                 A24= 
                 — 
                 6.674440E+00 
                 — 
                 — 
                 — 
               
               
                   
               
               
                 Surface # 
                 7 
                 8 
                 9 
                 10 
                 — 
               
               
                   
               
               
                 k= 
                  −4.15055E−01 
                  0.00000E+00 
                 −3.00998E+00 
                  −5.26761E+00 
                 — 
               
               
                 A4= 
                 −3.064752E−01 
                  1.520898E−01 
                 2.493458E−01 
                 −2.024565E−01 
                 — 
               
               
                 A6= 
                  5.112348E−01 
                 −2.657730E−01 
                 −5.159633E−01  
                 −5.788324E−02 
                 — 
               
               
                 A8= 
                 −1.155657E+00 
                  2.181841E−01 
                 6.477284E−01 
                  1.732949E−01 
                 — 
               
               
                 A10= 
                  2.416155E+00 
                 −7.258234E−02 
                 −5.587841E−01  
                 −1.194508E−01 
                 — 
               
               
                 A12= 
                 −3.571478E+00 
                 −1.855467E−02 
                 3.507305E−01 
                  4.583165E−02 
                 — 
               
               
                 A14= 
                  3.220439E+00 
                  3.322445E−02 
                 −1.457786E−01  
                 −1.116481E−02 
                 — 
               
               
                 A16= 
                 −1.570954E+00 
                 −1.753898E−02 
                 3.594056E−02 
                  1.777623E−03 
                 — 
               
               
                 A18= 
                  3.182687E−01 
                  4.617317E−03 
                 −4.606270E−03  
                 −1.798310E−04 
                 — 
               
               
                 A20= 
                 — 
                 −5.156965E−04 
                 2.264949E−04 
                  1.046604E−05 
                 — 
               
               
                 A22= 
                 — 
                 — 
                 — 
                 −2.653693E−07 
                 — 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 Freeform Coefficients 
               
            
           
           
               
               
               
               
            
               
                 Surface # 
                 11 
                 Surface # 
                 11 
               
               
                   
               
               
                 kx= 
                  −3.19296E+00 
                 ky= 
                  −3.19296E+00 
               
               
                 Ax4= 
                 −2.497000E−01 
                 Ay4= 
                 −2.504796E−01 
               
               
                 Ax6= 
                  1.852500E−01 
                 Ay6= 
                  1.852500E−01 
               
               
                 Ax8= 
                 −1.058729E−01 
                 Ay8= 
                 −1.058729E−01 
               
               
                 Ax10= 
                  4.950835E−02 
                 Ay10= 
                  4.950835E−02 
               
               
                 Ax12= 
                 −1.947340E−02 
                 Ay12= 
                 −1.947340E−02 
               
               
                 Ax14= 
                  6.494940E−03 
                 Ay14= 
                  6.494940E−03 
               
               
                 Ax16= 
                 −1.798574E−03 
                 Ay16= 
                 −1.798574E−03 
               
               
                 Ax18= 
                  3.902035E−04 
                 Ay18= 
                  3.902035E−04 
               
               
                 Ax20= 
                 −6.156933E−05 
                 Ay20= 
                 −6.156933E−05 
               
               
                 Ax22= 
                  6.485794E−06 
                 Ay22= 
                  6.485794E−06 
               
               
                 Ax24= 
                 −4.017963E−07 
                 Ay24= 
                 −4.017963E−07 
               
               
                 Ax26= 
                  1.096257E−08 
                 Ay26= 
                  1.096257E−08 
               
               
                   
               
            
           
         
       
     
     In the 2nd embodiment, the equations of the freeform surface profiles and the axisymmetric aspheric surface profiles of the aforementioned lens elements are the same as the equations of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 2nd embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 4, Table 5 and Table 6 as the following values and satisfy the following conditions: 
     
       
         
           
               
             
               
                   
               
               
                 2nd Embodiment 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 fD [mm] 
                 1.80 
                 T34/T23 
                 2.87 
               
               
                 fX [mm] 
                 1.80 
                 TL/f 
                 2.94 
               
               
                 fY [mm] 
                 1.80 
                 TL/ImgH 
                 1.80 
               
               
                 Fno 
                 2.40 
                 (R9 + R10)/(R9 − R10) 
                 3.45 
               
               
                 HFOVD [deg.] 
                 59.9 
                 R1/f 
                 −2.00 
               
               
                 HFOVX [deg.] 
                 52.6 
                 R1/f1 
                 0.87 
               
               
                 HFOVY [deg.] 
                 44.1 
                 R8/f 
                 −0.62 
               
               
                 ImgHD [mm] 
                 2.93 
                 f/f5 
                 −0.69 
               
               
                 ImgHX [mm] 
                 2.36 
                 f123/f 
                 1.82 
               
               
                 ImgHY [mm] 
                 1.75 
                 f4/CT4 
                 2.97 
               
               
                 (V2 + V4)/V3 
                 6.10 
                 f45/f 
                 2.55 
               
               
                 (Vi/Ni) min 
                 10.90 
                 HFOV [deg.] 
                 59.9 
               
               
                 V3 + V5 
                 38.8 
                 Y52/Y11 
                 1.44 
               
               
                 (CT1 + CT2 + CT4)/ 
                 3.75 
                 |dSAG|max [um] 
                 3.27 
               
               
                 (CT3 + CT5) 
               
               
                 (CT2 + CT3 + CT4 + 
                 3.82 
                 |dSAG|max/CTF 
                 1.06E−02 
               
               
                 CT5)/CT1 
               
               
                 CT1/CT4 
                 0.77 
                 — 
                 — 
               
               
                   
               
            
           
         
       
     
     3rd Embodiment 
       FIG. 5  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 3rd embodiment of the present disclosure.  FIG. 6  shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 3rd embodiment. In  FIG. 5 , the image capturing unit includes the optical photographing lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor  380 . The optical photographing lens assembly includes, in order from an object side to an image side along an optical path, a first lens element  310 , an aperture stop  300 , a second lens element  320 , a third lens element  330 , a fourth lens element  340 , a fifth lens element  350 , a filter  360  and an image surface  370 . The optical photographing lens assembly includes five lens elements ( 310 ,  320 ,  330 ,  340  and  350 ) with no additional lens element disposed between each of the adjacent five lens elements. 
     The first lens element  310  with negative refractive power has an object-side surface  311  being concave in a paraxial region thereof and an image-side surface  312  being concave in a paraxial region thereof. The first lens element  310  is made of plastic material and has the object-side surface  311  and the image-side surface  312  being both aspheric. The object-side surface  311  of the first lens element  310  has one critical point in an off-axis region thereof and in a maximum image height direction. 
     The second lens element  320  with positive refractive power has an object-side surface  321  being convex in a paraxial region thereof and an image-side surface  322  being convex in a paraxial region thereof. The second lens element  320  is made of plastic material and has the object-side surface  321  and the image-side surface  322  being both aspheric. 
     The third lens element  330  with negative refractive power has an object-side surface  331  being convex in a paraxial region thereof and an image-side surface  332  being concave in a paraxial region thereof. The third lens element  330  is made of plastic material and has the object-side surface  331  and the image-side surface  332  being both aspheric. 
     The fourth lens element  340  with positive refractive power has an object-side surface  341  being convex in a paraxial region thereof and an image-side surface  342  being convex in a paraxial region thereof. The fourth lens element  340  is made of plastic material and has the object-side surface  341  and the image-side surface  342  being both aspheric. 
     The fifth lens element  350  with negative refractive power has an object-side surface  351  being convex in a paraxial region thereof and an image-side surface  352  being concave in a paraxial region thereof. The fifth lens element  350  is made of plastic material and has the object-side surface  351  being aspheric and the image-side surface  352  being a freeform surface. The object-side surface  351  of the fifth lens element  350  has two critical points in an off-axis region thereof and in the maximum image height direction. The image-side surface  352  of the fifth lens element  350  has one critical point in an off-axis region thereof and in the maximum image height direction. 
     The filter  360  is made of glass material and located between the fifth lens element  350  and the image surface  370 , and will not affect the focal length of the optical photographing lens assembly. The image sensor  380  is disposed on or near the image surface  370  of the optical photographing lens assembly. 
     In this embodiment, the maximum image height direction corresponds to a diagonal direction D of a photosensitive area of the image sensor  380 . 
     In this embodiment, the image-side surface  352  of the fifth lens element  350  satisfies the following conditions: |dSAG|max=3.63 um; and |dSAG|max/CTF=1.17E-02. 
     The detailed optical data of the 3rd embodiment are shown in Table 7, the aspheric surface data are shown in Table 8 and the freeform surface data are shown in Table 9 below. 
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 3rd Embodiment 
               
               
                 fD = 1.73 mm, fX = 1.73 mm, fY = 1.73 mm, Fno = 2.40 
               
               
                 HFOVD = 59.9 deg., HFOVX = 53.5 deg., HFOVY = 45.1 deg. 
               
               
                 ImgHD = 2.93 mm, ImgHX = 2.36 mm, ImgHY = 1.75 mm 
               
            
           
           
               
               
               
               
            
               
                   
                 Curvature Radius 
                   
                 Focal Length 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Surface # 
                   
                 (Y-dir.) 
                 (X-dir.) 
                   
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 (Y-dir.) 
                 (X-dir.) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                 Lens 1 
                 −2.5171 
                   
                 (ASP) 
                 0.627 
                 Plastic 
                 1.545 
                 56.1 
                 −3.51 
                   
               
               
                 2 
                   
                 8.6969 
                   
                 (ASP) 
                 1.114 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 3 
                 Ape. Stop 
                 Plano 
                 −0.026  
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 4 
                 Lens 2 
                 2.4823 
                   
                 (ASP) 
                 0.859 
                 Plastic 
                 1.544 
                 56.0 
                 1.91 
                   
               
               
                 5 
                   
                 −1.5660 
                   
                 (ASP) 
                 0.235 
               
               
                 6 
                 Lens 3 
                 5.0721 
                   
                 (ASP) 
                 0.256 
                 Plastic 
                 1.686 
                 18.4 
                 −6.68 
               
               
                 7 
                   
                 2.3581 
                   
                 (ASP) 
                 0.426 
               
               
                 8 
                 Lens 4 
                 4.3585 
                   
                 (ASP) 
                 0.818 
                 Plastic 
                 1.544 
                 56.0 
                 2.20 
               
               
                 9 
                   
                 −1.5409 
                   
                 (ASP) 
                 0.030 
               
               
                 10 
                 Lens 5 
                 1.3722 
                   
                 (ASP) 
                 0.310 
                 Plastic 
                 1.669 
                 19.5 
                 −2.59 
                 −2.59 
               
               
                 11 
                   
                 0.6963 
                 0.6963 
                 (FFS) 
                 0.501 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 12 
                 Filter 
                 Plano 
                 0.210 
                 Glass 
                 1.517 
                 64.2 
                 — 
                   
               
               
                 13 
                   
                 Plano 
                 0.338 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm (d-line). 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 8 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface # 
                 1 
                 2 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k= 
                  0.00000E+00 
                  −9.90000E+01 
                  0.00000E+00 
                 −2.35496E−01 
                  1.12208E+01 
               
               
                 A4= 
                  3.317200E−01 
                  4.639607E−01 
                 −1.572599E−01 
                 −2.311117E−01  
                 −4.167388E−01 
               
               
                 A6= 
                 −3.184651E−01 
                 −1.860714E−01 
                  1.887085E+00 
                 3.935449E−01 
                  9.398828E−01 
               
               
                 A8= 
                  3.029795E−01 
                 −1.234181E+00 
                 −2.990535E+01 
                 −1.451032E+00  
                 −2.715380E+00 
               
               
                 A10= 
                 −2.297690E−01 
                  9.793065E+00 
                  2.573523E+02 
                 1.613347E+00 
                  4.801935E+00 
               
               
                 A12= 
                  1.303832E−01 
                 −3.713084E+01 
                 −1.388645E+03 
                 5.928340E−02 
                 −5.797452E+00 
               
               
                 A14= 
                 −5.295792E−02 
                  8.720175E+01 
                  4.696526E+03 
                 −1.829621E+00  
                  3.802077E+00 
               
               
                 A16= 
                  1.477598E−02 
                 −1.311793E+02 
                 −9.691122E+03 
                 7.997558E−01 
                 −9.046560E−01 
               
               
                 A18= 
                 −2.672682E−03 
                  1.259341E+02 
                  1.110900E+04 
                 — 
                 — 
               
               
                 A20= 
                  2.810009E−04 
                 −7.415214E+01 
                 −5.433613E+03 
                 — 
                 — 
               
               
                 A22= 
                 −1.300500E−05 
                  2.422164E+01 
                 — 
                 — 
                 — 
               
               
                 A24= 
                 — 
                 −3.340293E+00 
                 — 
                 — 
                 — 
               
               
                   
               
               
                 Surface # 
                 7 
                 8 
                 9 
                 10 
                 — 
               
               
                   
               
               
                 k= 
                  5.12068E−01 
                  0.00000E+00 
                  −3.78525E+00 
                  −9.68438E+00 
                 — 
               
               
                 A4= 
                 −2.746482E−01 
                  6.312785E−02 
                  3.182010E−01 
                 −1.588402E−01 
                 — 
               
               
                 A6= 
                  5.160318E−01 
                 −1.869255E−01 
                 −6.929520E−01 
                 −2.279466E−01 
                 — 
               
               
                 A8= 
                 −8.826743E−01 
                  1.590013E−01 
                  8.313000E−01 
                  3.741619E−01 
                 — 
               
               
                 A10= 
                  1.063814E+00 
                 −4.829475E−02 
                 −6.809738E−01 
                 −2.452937E−01 
                 — 
               
               
                 A12= 
                 −1.008520E+00 
                 −2.787544E−02 
                  3.884911E−01 
                  9.535705E−02 
                 — 
               
               
                 A14= 
                  7.364819E−01 
                  3.750809E−02 
                 −1.466501E−01 
                 −2.390246E−02 
                 — 
               
               
                 A16= 
                 −3.366654E−01 
                 −1.785898E−02 
                  3.505635E−02 
                  3.895635E−03 
                 — 
               
               
                 A18= 
                  6.807971E−02 
                  4.128752E−03 
                 −5.051378E−03 
                 −3.975117E−04 
                 — 
               
               
                 A20= 
                 — 
                 −3.869921E−04 
                  3.984135E−04 
                  2.296127E−05 
                 — 
               
               
                 A22= 
                 — 
                 — 
                 −1.323252E−05 
                 −5.702984E−07 
                 — 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 9 
               
             
            
               
                   
               
               
                 Freeform Coefficients 
               
            
           
           
               
               
               
               
            
               
                 Surface # 
                 11 
                 Surface # 
                 11 
               
               
                   
               
               
                 kx= 
                  −3.95420E+00 
                 ky= 
                  −3.95420E+00 
               
               
                 Ax4= 
                 −2.224000E−01 
                 Ay4= 
                 −2.232337E−01 
               
               
                 Ax6= 
                  1.052594E−01 
                 Ay6= 
                  1.052594E−01 
               
               
                 Ax8= 
                  6.086610E−03 
                 Ay8= 
                  6.086610E−03 
               
               
                 Ax10= 
                 −4.962885E−02 
                 Ay10= 
                 −4.962885E−02 
               
               
                 Ax12= 
                  4.192841E−02 
                 Ay12= 
                  4.192841E−02 
               
               
                 Ax14= 
                 −2.033674E−02 
                 Ay14= 
                 −2.033674E−02 
               
               
                 Ax16= 
                  6.399989E−03 
                 Ay16= 
                  6.399989E−03 
               
               
                 Ax18= 
                 −1.337118E−03 
                 Ay18= 
                 −1.337118E−03 
               
               
                 Ax20= 
                  1.833028E−04 
                 Ay20= 
                  1.833028E−04 
               
               
                 Ax22= 
                 −1.577557E−05 
                 Ay22= 
                 −1.577557E−05 
               
               
                 Ax24= 
                  7.694633E−07 
                 Ay24= 
                  7.694633E−07 
               
               
                 Ax26= 
                 −1.614698E−08 
                 Ay26= 
                 −1.614698E−08 
               
               
                   
               
            
           
         
       
     
     In the 3rd embodiment, the equations of the freeform surface profiles and the axisymmetric aspheric surface profiles of the aforementioned lens elements are the same as the equations of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 3rd embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 7, Table 8 and Table 9 as the following values and satisfy the following conditions: 
     
       
         
           
               
             
               
                   
               
               
                 3rd Embodiment 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 fD [mm] 
                 1.73 
                 T34/T23 
                 1.81 
               
               
                 fX [mm] 
                 1.73 
                 TL/f 
                 3.29 
               
               
                 fY [mm] 
                 1.73 
                 TL/ImgH 
                 1.94 
               
               
                 Fno 
                 2.40 
                 (R9 + R10)/(R9 − R10) 
                 3.06 
               
               
                 HFOVD [deg.] 
                 59.9 
                 R1/f 
                 −1.45 
               
               
                 HFOVX [deg.] 
                 53.5 
                 R1/f1 
                 0.72 
               
               
                 HFOVY [deg.] 
                 45.1 
                 R8/f 
                 −0.89 
               
               
                 ImgHD [mm] 
                 2.93 
                 f/f5 
                 −0.67 
               
               
                 ImgHX [mm] 
                 2.36 
                 f123/f 
                 1.72 
               
               
                 ImgHY [mm] 
                 1.75 
                 T4/CT4 
                 2.69 
               
               
                 (V2 + V4)/V3 
                 6.09 
                 f45/f 
                 3.20 
               
               
                 (Vi/Ni) min 
                 10.90 
                 HFOV [deg.] 
                 59.9 
               
               
                 V3 + V5 
                 37.8 
                 Y52/Y11 
                 1.28 
               
               
                 (CT1 + CT2 + CT4)/ 
                 4.07 
                 |dSAG|max [um] 
                 3.63 
               
               
                 (CT3 + CT5) 
               
               
                 (CT2 + CT3 + CT4 + 
                 3.58 
                 |dSAG|max/CTF 
                 1.17E−02 
               
               
                 CT5)/CT1 
               
               
                 CT1/CT4 
                 0.77 
                 — 
                 — 
               
               
                   
               
            
           
         
       
     
     4th Embodiment 
       FIG. 7  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 4th embodiment of the present disclosure.  FIG. 8  shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 4th embodiment. In  FIG. 7 , the image capturing unit includes the optical photographing lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor  480 . The optical photographing lens assembly includes, in order from an object side to an image side along an optical path, a first lens element  410 , an aperture stop  400 , a second lens element  420 , a third lens element  430 , a fourth lens element  440 , a fifth lens element  450 , a filter  460  and an image surface  470 . The optical photographing lens assembly includes five lens elements ( 410 ,  420 ,  430 ,  440  and  450 ) with no additional lens element disposed between each of the adjacent five lens elements. 
     The first lens element  410  with negative refractive power has an object-side surface  411  being concave in a paraxial region thereof and an image-side surface  412  being concave in a paraxial region thereof. The first lens element  410  is made of plastic material and has the object-side surface  411  and the image-side surface  412  being both aspheric. The object-side surface  411  of the first lens element  410  has one critical point in an off-axis region thereof and in a maximum image height direction. 
     The second lens element  420  with positive refractive power has an object-side surface  421  being convex in a paraxial region thereof and an image-side surface  422  being convex in a paraxial region thereof. The second lens element  420  is made of plastic material and has the object-side surface  421  and the image-side surface  422  being both aspheric. 
     The third lens element  430  with negative refractive power has an object-side surface  431  being convex in a paraxial region thereof and an image-side surface  432  being concave in a paraxial region thereof. The third lens element  430  is made of plastic material and has the object-side surface  431  and the image-side surface  432  being both aspheric. 
     The fourth lens element  440  with positive refractive power has an object-side surface  441  being convex in a paraxial region thereof and an image-side surface  442  being convex in a paraxial region thereof. The fourth lens element  440  is made of plastic material and has the object-side surface  441  and the image-side surface  442  being both aspheric. 
     The fifth lens element  450  with negative refractive power has an object-side surface  451  being convex in a paraxial region thereof and an image-side surface  452  being concave in a paraxial region thereof. The fifth lens element  450  is made of plastic material and has the object-side surface  451  being aspheric and the image-side surface  452  being a freeform surface. The object-side surface  451  of the fifth lens element  450  has two critical points in an off-axis region thereof and in the maximum image height direction. The image-side surface  452  of the fifth lens element  450  has one critical point in an off-axis region thereof and in the maximum image height direction. 
     The filter  460  is made of glass material and located between the fifth lens element  450  and the image surface  470 , and will not affect the focal length of the optical photographing lens assembly. The image sensor  480  is disposed on or near the image surface  470  of the optical photographing lens assembly. 
     In this embodiment, the maximum image height direction corresponds to a diagonal direction D of a photosensitive area of the image sensor  480 . 
     In this embodiment, the image-side surface  452  of the fifth lens element  450  satisfies the following conditions: |dSAG|max=2.43 um; and |dSAG|max/CTF=7.27E-03. 
     The detailed optical data of the 4th embodiment are shown in Table 10, the aspheric surface data are shown in Table 11 and the freeform surface data are shown in Table 12 below. 
     
       
         
           
               
             
               
                 TABLE 10 
               
             
            
               
                   
               
               
                 4th Embodiment 
               
               
                 fD = 1.73 mm, fX = 1.73 mm, fY = 1.73 mm, Fno = 2.45 
               
               
                 HFOVD = 60.0 deg., HFOVX = 53.9 deg., HFOVY = 45.6 deg. 
               
               
                 ImgHD = 2.93 mm, ImgHX = 2.36 mm, ImgHY = 1.75 mm 
               
            
           
           
               
               
               
               
            
               
                   
                 Curvature Radius 
                   
                 Focal Length 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Surface # 
                   
                 (Y-dir.) 
                 (X-dir.) 
                   
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 (Y-dir.) 
                 (X-dir.) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                 Lens 1 
                 −2.4927 
                   
                 (ASP) 
                 0.618 
                 Plastic 
                 1.545 
                 56.1 
                 −3.26 
                   
               
               
                 2 
                   
                 6.7378 
                   
                 (ASP) 
                 1.097 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 3 
                 Ape. Stop 
                 Plano 
                 −0.035  
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 4 
                 Lens 2 
                 2.3206 
                   
                 (ASP) 
                 0.854 
                 Plastic 
                 1.544 
                 55.9 
                 1.85 
                   
               
               
                 5 
                   
                 −1.5411 
                   
                 (ASP) 
                 0.227 
               
               
                 6 
                 Lens 3 
                 11.4707 
                   
                 (ASP) 
                 0.280 
                 Plastic 
                 1.686 
                 18.4 
                 −5.94 
               
               
                 7 
                   
                 2.9789 
                   
                 (ASP) 
                 0.421 
               
               
                 8 
                 Lens 4 
                 3.5524 
                   
                 (ASP) 
                 0.893 
                 Plastic 
                 1.544 
                 56.0 
                 2.20 
               
               
                 9 
                   
                 −1.6468 
                   
                 (ASP) 
                 0.030 
               
               
                 10 
                 Lens 5 
                 1.6041 
                   
                 (ASP) 
                 0.334 
                 Plastic 
                 1.669 
                 19.5 
                 −2.61 
                 −2.61 
               
               
                 11 
                   
                 0.7661 
                 0.7661 
                 (FFS) 
                 0.501 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 12 
                 Filter 
                 Plano 
                 0.210 
                 Glass 
                 1.517 
                 64.2 
                 — 
                   
               
               
                 13 
                   
                 Plano 
                 0.309 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm (d-line). 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 11 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface # 
                 1 
                 2 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k= 
                  0.00000E+00 
                  −1.63731E+00 
                  0.00000E+00 
                  7.78926E−01 
                  0.00000E+00 
               
               
                 A4= 
                  3.544997E−01 
                  5.144102E−01 
                 −1.490725E−01 
                 −1.914971E−01 
                 −4.380798E−01 
               
               
                 A6= 
                 −3.781391E−01 
                 −6.706461E−01 
                  2.188311E+00 
                 −8.284806E−02 
                  9.559503E−01 
               
               
                 A8= 
                  3.990181E−01 
                  1.531983E+00 
                 −4.414427E+01 
                  1.469697E+00 
                 −3.061981E+00 
               
               
                 A10= 
                 −3.288203E−01 
                 −1.638423E−01 
                  4.717446E+02 
                 −7.005894E+00 
                  7.541145E+00 
               
               
                 A12= 
                  1.973882E−01 
                 −1.392987E+01 
                 −3.088569E+03 
                  1.315522E+01 
                 −1.436159E+01 
               
               
                 A14= 
                 −8.299840E−02 
                  5.282976E+01 
                  1.240849E+04 
                 −1.120124E+01 
                  1.729490E+01 
               
               
                 A16= 
                  2.361303E−02 
                 −1.003733E+02 
                 −2.960345E+04 
                  2.771709E+00 
                 −1.210253E+01 
               
               
                 A18= 
                 −4.311689E−03 
                  1.117219E+02 
                  3.795658E+04 
                 — 
                  3.959319E+00 
               
               
                 A20= 
                  4.547277E−04 
                 −7.324240E+01 
                 −1.987276E+04 
                 — 
                 — 
               
               
                 A22= 
                 −2.101965E−05 
                  2.603468E+01 
                 — 
                 — 
                 — 
               
               
                 A24= 
                 — 
                 −3.850952E+00 
                 — 
                 — 
                 — 
               
               
                   
               
               
                 Surface # 
                 7 
                 8 
                 9 
                 10 
                 — 
               
               
                   
               
               
                 k= 
                  1.94725E+00 
                  0.00000E+00 
                  −4.13754E+00 
                  −1.05479E+01 
                 — 
               
               
                 A4= 
                 −3.122086E−01 
                  2.195764E−02 
                  2.907242E−01 
                 −1.561697E−01 
                 — 
               
               
                 A6= 
                  7.684803E−01 
                 −1.133388E−01 
                 −5.637653E−01 
                 −9.419651E−02 
                 — 
               
               
                 A8= 
                 −1.903167E+00 
                  1.281946E−01 
                  6.502476E−01 
                  1.365287E−01 
                 — 
               
               
                 A10= 
                  3.816249E+00 
                 −1.012802E−01 
                 −5.313673E−01 
                 −6.140264E−02 
                 — 
               
               
                 A12= 
                 −5.402367E+00 
                  5.204451E−02 
                  2.990998E−01 
                  1.461734E−02 
                 — 
               
               
                 A14= 
                  4.793163E+00 
                 −1.268639E−02 
                 −1.097100E−01 
                 −2.010020E−03 
                 — 
               
               
                 A16= 
                 −2.353668E+00 
                 −5.726188E−04 
                  2.537874E−02 
                  1.565781E−04 
                 — 
               
               
                 A18= 
                  4.872208E−01 
                  9.325946E−04 
                 −3.553225E−03 
                 −5.990540E−06 
                 — 
               
               
                 A20= 
                 — 
                 −1.357145E−04 
                  2.741743E−04 
                  4.928632E−08 
                 — 
               
               
                 A22= 
                 — 
                 — 
                 −8.932435E−06 
                  1.899624E−09 
                 — 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 12 
               
             
            
               
                   
               
               
                 Freeform Coefficients 
               
            
           
           
               
               
               
               
            
               
                 Surface # 
                 11 
                 Surface # 
                 11 
               
               
                   
               
               
                 kx= 
                  −3.95420E+00 
                 ky= 
                  −3.95420E+00 
               
               
                 Ax4= 
                 −2.136000E−01 
                 Ay4= 
                 −2.141343E−01 
               
               
                 Ax6= 
                  1.593006E−01 
                 Ay6= 
                  1.593006E−01 
               
               
                 Ax8= 
                 −1.182388E−01 
                 Ay8= 
                 −1.182388E−01 
               
               
                 Ax10= 
                  7.597406E−02 
                 Ay10= 
                  7.597406E−02 
               
               
                 Ax12= 
                 −3.451926E−02 
                 Ay12= 
                 −3.451926E−02 
               
               
                 Ax14= 
                  1.046755E−02 
                 Ay14= 
                  1.046755E−02 
               
               
                 Ax16= 
                 −2.087469E−03 
                 Ay16= 
                 −2.087469E−03 
               
               
                 Ax18= 
                  2.666226E−04 
                 Ay18= 
                  2.666226E−04 
               
               
                 Ax20= 
                 −2.039884E−05 
                 Ay20= 
                 −2.039884E−05 
               
               
                 Ax22= 
                  7.785033E−07 
                 Ay22= 
                  7.785033E−07 
               
               
                 Ax24= 
                 −4.492214E−09 
                 Ay24= 
                 −4.492214E−09 
               
               
                 Ax26= 
                 −3.947682E−10 
                 Ay26= 
                 −3.947682E−10 
               
               
                   
               
            
           
         
       
     
     In the 4th embodiment, the equations of the freeform surface profiles and the axisymmetric aspheric surface profiles of the aforementioned lens elements are the same as the equations of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 4th embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 10, Table 11 and Table 12 as the following values and satisfy the following conditions: 
     
       
         
           
               
             
               
                   
               
               
                 4th Embodiment 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 fD [mm] 
                 1.73 
                 T34/T23 
                 1.85 
               
               
                 fX [mm] 
                 1.73 
                 TL/f 
                 3.33 
               
               
                 fY [mm] 
                 1.73 
                 TL/ImgH 
                 1.96 
               
               
                 Fno 
                 2.45 
                 (R9 + R10)/(R9 − R10) 
                 2.83 
               
               
                 HFOVD [deg.] 
                 60.0 
                 R1/f 
                 −1.44 
               
               
                 HFOVX [deg.] 
                 53.9 
                 R1/f1 
                 0.76 
               
               
                 HFOVY [deg.] 
                 45.6 
                 R8/f 
                 −0.95 
               
               
                 ImgHD [mm] 
                 2.93 
                 f/f5 
                 −0.66 
               
               
                 ImgHX [mm] 
                 2.36 
                 f123/f 
                 1.80 
               
               
                 ImgHY [mm] 
                 1.75 
                 f4/CT4 
                 2.47 
               
               
                 (V2 + V4)/V3 
                 6.09 
                 f45/f 
                 3.06 
               
               
                 (Vi/Ni) min 
                 10.90 
                 HFOV [deg.] 
                 60.0 
               
               
                 V3 + V5 
                 37.8 
                 Y52/Y11 
                 1.28 
               
               
                 (CT1 + CT2 + CT4)/ 
                 3.85 
                 |dSAG|max [um] 
                 2.43 
               
               
                 (CT3 + CT5) 
               
               
                 (CT2 + CT3 + CT4 + 
                 3.82 
                 |dSAG|max/CTF 
                 7.27E−03 
               
               
                 CT5)/CT1 
               
               
                 CT1/CT4 
                 0.69 
                 — 
                 — 
               
               
                   
               
            
           
         
       
     
     5th Embodiment 
       FIG. 9  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 5th embodiment of the present disclosure.  FIG. 10  shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 5th embodiment. In  FIG. 9 , the image capturing unit includes the optical photographing lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor  580 . The optical photographing lens assembly includes, in order from an object side to an image side along an optical path, a first lens element  510 , an aperture stop  500 , a second lens element  520 , a third lens element  530 , a fourth lens element  540 , a fifth lens element  550 , a filter  560  and an image surface  570 . The optical photographing lens assembly includes five lens elements ( 510 ,  520 ,  530 ,  540  and  550 ) with no additional lens element disposed between each of the adjacent five lens elements. 
     The first lens element  510  with negative refractive power has an object-side surface  511  being concave in a paraxial region thereof and an image-side surface  512  being convex in a paraxial region thereof. The first lens element  510  is made of plastic material and has the object-side surface  511  and the image-side surface  512  being both aspheric. The object-side surface  511  of the first lens element  510  has one critical point in an off-axis region thereof and in a maximum image height direction. 
     The second lens element  520  with positive refractive power has an object-side surface  521  being convex in a paraxial region thereof and an image-side surface  522  being convex in a paraxial region thereof. The second lens element  520  is made of glass material and has the object-side surface  521  and the image-side surface  522  being both aspheric. 
     The third lens element  530  with negative refractive power has an object-side surface  531  being convex in a paraxial region thereof and an image-side surface  532  being concave in a paraxial region thereof. The third lens element  530  is made of plastic material and has the object-side surface  531  and the image-side surface  532  being both aspheric. 
     The fourth lens element  540  with positive refractive power has an object-side surface  541  being concave in a paraxial region thereof and an image-side surface  542  being convex in a paraxial region thereof. The fourth lens element  540  is made of plastic material and has the object-side surface  541  and the image-side surface  542  being both aspheric. 
     The fifth lens element  550  with negative refractive power has an object-side surface  551  being convex in a paraxial region thereof and an image-side surface  552  being concave in a paraxial region thereof. The fifth lens element  550  is made of plastic material and has the object-side surface  551  and the image-side surface  552  being both freeform surfaces. The object-side surface  551  of the fifth lens element  550  has one critical point in an off-axis region thereof and in the maximum image height direction. The image-side surface  552  of the fifth lens element  550  has one critical point in an off-axis region thereof and in the maximum image height direction. 
     The filter  560  is made of glass material and located between the fifth lens element  550  and the image surface  570 , and will not affect the focal length of the optical photographing lens assembly. The image sensor  580  is disposed on or near the image surface  570  of the optical photographing lens assembly. 
     In this embodiment, the maximum image height direction corresponds to a diagonal direction D of a photosensitive area of the image sensor  580 . 
     In this embodiment, the object-side surface  551  of the fifth lens element  550  satisfies the following conditions: |dSAG|max=0.50 um; and |dSAG|max/CTF=1.63E-03. The image-side surface  552  of the fifth lens element  550  satisfies the following conditions: |dSAG|max=4.72 um; and |dSAG|max/CTF=1.55E-02. 
     The detailed optical data of the 5th embodiment are shown in Table 13, the aspheric surface data are shown in Table 14 and the freeform surface data are shown in Table 15 below. 
     
       
         
           
               
             
               
                 TABLE 13 
               
             
            
               
                   
               
               
                 5th Embodiment 
               
               
                 fD = 1.96 mm, fX = 1.96 mm, fY = 1.97 mm, Fno = 2.29 
               
               
                 HFOVD = 57.8 deg., HFOVX = 50.2 deg., HFOVY = 41.5 deg. 
               
               
                 ImgHD = 2.93 mm, ImgHX = 2.36 mm, ImgHY = 1.75 mm 
               
            
           
           
               
               
               
               
            
               
                   
                 Curvature Radius 
                   
                 Focal Length 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Surface # 
                   
                 (Y-dir.) 
                 (X-dir.) 
                   
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 (Y-dir.) 
                 (X-dir.) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                 Lens 1 
                 −2.6117 
                   
                 (ASP) 
                 0.437 
                 Plastic 
                 1.545 
                 56.1 
                 −5.16 
                   
               
               
                 2 
                   
                 −39.1901 
                   
                 (ASP) 
                 0.950 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 3 
                 Ape. Stop 
                 Plano 
                 −0.010  
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 4 
                 Lens 2 
                 3.6938 
                   
                 (ASP) 
                 0.845 
                 Glass 
                 1.522 
                 62.2 
                 2.11 
                   
               
               
                 5 
                   
                 −1.4440 
                   
                 (ASP) 
                 0.201 
               
               
                 6 
                 Lens 3 
                 2.5184 
                   
                 (ASP) 
                 0.210 
                 Plastic 
                 1.679 
                 18.4 
                 −7.49 
               
               
                 7 
                   
                 1.6274 
                   
                 (ASP) 
                 0.538 
               
               
                 8 
                 Lens 4 
                 −31.0126 
                   
                 (ASP) 
                 0.703 
                 Plastic 
                 1.544 
                 56.0 
                 2.02 
               
               
                 9 
                   
                 −1.0709 
                   
                 (ASP) 
                 0.028 
               
               
                 10 
                 Lens 5 
                 1.0218 
                 1.0192 
                 (FFS) 
                 0.304 
                 Plastic 
                 1.639 
                 23.5 
                 −2.36 
                 −2.37 
               
               
                 11 
                   
                 0.5379 
                 0.5385 
                 (FFS) 
                 0.491 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 12 
                 Filter 
                 Plano 
                 0.110 
                 Glass 
                 1.517 
                 64.2 
                 — 
                   
               
               
                 13 
                   
                 Plano 
                 0.528 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm (d-line). 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 14 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 Surface # 
                 1 
                 2 
                 4 
                 5 
               
               
                   
               
               
                 k= 
                  0.00000E+00 
                  9.90000E+01 
                  −1.02274E+01 
                  1.91316E−01 
               
               
                 A4= 
                  3.753221E−01 
                 5.699621E−01 
                 −4.868427E−02 
                 −1.276070E−01  
               
               
                 A6= 
                 −3.885027E−01 
                 −1.924936E+00  
                 −6.653931E−02 
                 9.160295E−02 
               
               
                 A8= 
                  4.707322E−01 
                 1.266866E+01 
                 −5.504547E−01 
                 3.041977E−01 
               
               
                 A10= 
                 −5.284323E−01 
                 −5.496349E+01  
                  7.644855E−01 
                 −2.570987E+00  
               
               
                 A12= 
                  4.794019E−01 
                 1.509540E+02 
                 −1.058244E+00 
                 4.915425E+00 
               
               
                 A14= 
                 −3.144586E−01 
                 −2.667605E+02  
                 — 
                 −4.230142E+00  
               
               
                 A16= 
                  1.391658E−01 
                 3.057568E+02 
                 — 
                 1.225836E+00 
               
               
                 A18= 
                 −3.893818E−02 
                 −2.237412E+02  
                 — 
                 — 
               
               
                 A20= 
                  6.177219E−03 
                 9.973070E+01 
                 — 
                 — 
               
               
                 A22= 
                 −4.219770E−04 
                 −2.438936E+01  
                 — 
                 — 
               
               
                 A24= 
                 — 
                 2.476513E+00 
                 — 
                 — 
               
               
                   
               
               
                 Surface # 
                 6 
                   
                 8 
                 9 
               
               
                   
               
               
                 k= 
                  5.35522E−01 
                  −8.99042E−01 
                  0.00000E+00 
                 −2.97568E+00 
               
               
                 A4= 
                 −3.683840E−01 
                 −2.819725E−01 
                 2.073319E−01 
                 3.004373E−01 
               
               
                 A6= 
                  5.831867E−01 
                  3.255215E−01 
                 −4.931480E−01  
                 −7.217323E−01  
               
               
                 A8= 
                 −1.214822E+00 
                 −3.701527E−01 
                 7.224755E−01 
                 9.550508E−01 
               
               
                 A10= 
                  1.906484E+00 
                  3.997090E−01 
                 −7.463333E−01  
                 −8.046116E−01  
               
               
                 A12= 
                 −2.135826E+00 
                 −4.432073E−01 
                 5.414727E−01 
                 4.648828E−01 
               
               
                 A14= 
                  1.280423E+00 
                  3.518085E−01 
                 −2.575266E−01  
                 −1.775893E−01  
               
               
                 A16= 
                 −2.852201E−01 
                 −1.514022E−01 
                 7.301606E−02 
                 4.149930E−02 
               
               
                 A18= 
                 — 
                  2.654649E−02 
                 −1.044730E−02  
                 −5.268304E−03  
               
               
                 A20= 
                 — 
                 — 
                 4.467766E−04 
                 2.739487E−04 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 15 
               
             
            
               
                   
               
               
                 Freeform Coefficients 
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface # 
                 10 
                 11 
                 Surface # 
                 10 
                 11 
               
               
                   
               
               
                 kx= 
                  −5.53988E+00 
                  −3.16916E+00 
                 ky= 
                  −5.47249E+00 
                  −3.20650E+00 
               
               
                 Ax4= 
                 −2.659258E−01 
                 −3.048863E−01 
                 Ay4= 
                 −2.673403E−01 
                 −2.977381E−01 
               
               
                 Ax6= 
                 −2.615247E−02 
                  2.785501E−01 
                 Ay6= 
                 −2.629158E−02 
                  2.720193E−01 
               
               
                 Ax8= 
                  1.705845E−01 
                 −2.090656E−01 
                 Ay8= 
                  1.714918E−01 
                 −2.041640E−01 
               
               
                 Ax10= 
                 −1.139787E−01 
                  1.253465E−01 
                 Ay10= 
                 −1.145849E−01 
                  1.224077E−01 
               
               
                 Ax12= 
                  3.524981E−02 
                 −5.636180E−02 
                 Ay12= 
                  3.543731E−02 
                 −5.504036E−02 
               
               
                 Ax14= 
                 −4.485714E−03 
                  1.809683E−02 
                 Ay14= 
                 −4.509574E−03 
                  1.767254E−02 
               
               
                 Ax16= 
                 −3.055007E−04 
                 −4.007058E−03 
                 Ay16= 
                 −3.071257E−04 
                 −3.913111E−03 
               
               
                 Ax18= 
                  1.706327E−04 
                  5.878699E−04 
                 Ay18= 
                  1.715403E−04 
                  5.740870E−04 
               
               
                 Ax20= 
                 −1.995290E−05 
                 −5.338912E−05 
                 Ay20= 
                 −2.005904E−05 
                 −5.213738E−05 
               
               
                 Ax22= 
                  7.989230E−07 
                  2.580700E−06 
                 Ay22= 
                  8.031726E−07 
                  2.520194E−06 
               
               
                 Ax24= 
                 — 
                 −3.672096E−08 
                 Ay24= 
                 — 
                 −3.586002E−08 
               
               
                 Ax26= 
                 — 
                 −9.904603E−10 
                 Ay26= 
                 — 
                 −9.672385E−10 
               
               
                   
               
            
           
         
       
     
     In the 5th embodiment, the equations of the freeform surface profiles and the axisymmetric aspheric surface profiles of the aforementioned lens elements are the same as the equations of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 5th embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 13, Table 14 and Table 15 as the following values and satisfy the following conditions: 
     
       
         
           
               
             
               
                   
               
               
                 5th Embodiment 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 fD [mm] 
                 1.96 
                 T34/T23 
                 2.68 
               
               
                 fX [mm] 
                 1.96 
                 TL/f 
                 2.72 
               
               
                 fY [mm] 
                 1.97 
                 TL/ImgH 
                 1.82 
               
               
                 Fno 
                 2.29 
                 (R9 + R10)/(R9 − R10) 
                 3.24 
               
               
                 HFOVD [deg.] 
                 57.8 
                 R1/f 
                 −1.33 
               
               
                 HFOVX [deg.] 
                 50.2 
                 R1/f1 
                 0.51 
               
               
                 HFOVY [deg.] 
                 41.5 
                 R8/f 
                 −0.55 
               
               
                 ImgHD [mm] 
                 2.93 
                 f/f5 
                 −0.83 
               
               
                 ImgHX [mm] 
                 2.36 
                 f123/f 
                 1.69 
               
               
                 ImgHY [mm] 
                 1.75 
                 f4/CT4 
                 2.88 
               
               
                 (V2 + V4)/V3 
                 6.41 
                 f45/f 
                 2.78 
               
               
                 (Vi/Ni) min 
                 10.98 
                 HFOV [deg.] 
                 57.8 
               
               
                 V3 + V5 
                 41.9 
                 Y52/Y11 
                 1.43 
               
               
                 (CT1 + CT2 + CT4)/ 
                 3.86 
                 |dSAG|max [um] 
                 0.50; 4.72 
               
               
                 (CT3 + CT5) 
               
               
                 (CT2 + CT3 + CT4 + 
                 4.72 
                 |dSAG|max/CTF 
                 1.63E−03; 
               
               
                 CT5)/CT1 
                   
                   
                 1.55E−02  
               
               
                 CT1/CT4 
                 0.62 
                 — 
                 — 
               
               
                   
               
            
           
         
       
     
     6th Embodiment 
       FIG. 11  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 6th embodiment of the present disclosure.  FIG. 12  shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 6th embodiment. In  FIG. 11 , the image capturing unit includes the optical photographing lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor  680 . The optical photographing lens assembly includes, in order from an object side to an image side along an optical path, a first lens element  610 , an aperture stop  600 , a second lens element  620 , a third lens element  630 , a fourth lens element  640 , a fifth lens element  650 , a filter  660  and an image surface  670 . The optical photographing lens assembly includes five lens elements ( 610 ,  620 ,  630 ,  640  and  650 ) with no additional lens element disposed between each of the adjacent five lens elements. 
     The first lens element  610  with negative refractive power has an object-side surface  611  being concave in a paraxial region thereof and an image-side surface  612  being concave in a paraxial region thereof. The first lens element  610  is made of plastic material and has the object-side surface  611  and the image-side surface  612  being both freeform surfaces. The object-side surface  611  of the first lens element  610  has one critical point in an off-axis region thereof and in a maximum image height direction. 
     The second lens element  620  with positive refractive power has an object-side surface  621  being convex in a paraxial region thereof and an image-side surface  622  being convex in a paraxial region thereof. The second lens element  620  is made of plastic material and has the object-side surface  621  and the image-side surface  622  being both aspheric. 
     The third lens element  630  with positive refractive power has an object-side surface  631  being convex in a paraxial region thereof and an image-side surface  632  being concave in a paraxial region thereof. The third lens element  630  is made of plastic material and has the object-side surface  631  and the image-side surface  632  being both aspheric. 
     The fourth lens element  640  with positive refractive power has an object-side surface  641  being concave in a paraxial region thereof and an image-side surface  642  being convex in a paraxial region thereof. The fourth lens element  640  is made of plastic material and has the object-side surface  641  and the image-side surface  642  being both aspheric. 
     The fifth lens element  650  with negative refractive power has an object-side surface  651  being convex in a paraxial region thereof and an image-side surface  652  being concave in a paraxial region thereof. The fifth lens element  650  is made of plastic material and has the object-side surface  651  and the image-side surface  652  being both freeform surfaces. The object-side surface  651  of the fifth lens element  650  has one critical point in an off-axis region thereof and in the maximum image height direction. The image-side surface  652  of the fifth lens element  650  has one critical point in an off-axis region thereof and in the maximum image height direction. 
     The filter  660  is made of glass material and located between the fifth lens element  650  and the image surface  670 , and will not affect the focal length of the optical photographing lens assembly. The image sensor  695  is disposed on or near the image surface  670  of the optical photographing lens assembly. 
     In this embodiment, the maximum image height direction corresponds to a diagonal direction D of a photosensitive area of the image sensor  680 . 
     In this embodiment, the object-side surface  611  of the first lens element  610  satisfies the following conditions: |dSAG|max=0.60 um; and |dSAG|max/CTF=1.04E-03. The image-side surface  612  of the first lens element  610  satisfies the following conditions: |dSAG|max=0.48 urn; and |dSAG|max/CTF=8.34E-04. The object-side surface  651  of the fifth lens element  650  satisfies the following conditions: |dSAG|max=1.92 um; and |dSAG|max/CTF=5.19E-03. The image-side surface  652  of the fifth lens element  650  satisfies the following conditions: |dSAG|max=3.64 um; and |dSAG|max/CTF=9.83E-03. 
     The detailed optical data of the 6th embodiment are shown in Table 16, the aspheric surface data are shown in Table 17 and the freeform surface data are shown in Table 18 below. 
     
       
         
           
               
             
               
                 TABLE 16 
               
             
            
               
                   
               
               
                 6th Embodiment 
               
               
                 fD = 1.76 mm, fX = 1.76 mm, fY = 1.76 mm, Fno = 2.35 
               
               
                 HFOVD = 60.0 deg., HFOVX = 53.2 deg., HFOVY = 44.8 deg. 
               
               
                 ImgHD = 2.93 mm, ImgHX = 2.36 mm, ImgHY = 1.75 mm 
               
            
           
           
               
               
               
               
            
               
                   
                 Curvature Radius 
                   
                 Focal Length 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Surface # 
                   
                 (Y-dir.) 
                 (X-dir.) 
                   
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 (Y-dir.) 
                 (X-dir.) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                 Lens 1 
                 −3.2390 
                 −3.2418 
                 (FFS) 
                 0.572 
                 Plastic 
                 1.545 
                 56.1 
                 −3.87 
                 −3.87 
               
               
                 2 
                   
                 6.3999 
                 6.4263 
                 (FFS) 
                 0.761 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 3 
                 Ape. Stop 
                 Plano 
                 −0.017  
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 4 
                 Lens 2 
                 2.9123 
                   
                 (ASP) 
                 1.024 
                 Plastic 
                 1.544 
                 56.0 
                 2.90 
                   
               
               
                 5 
                   
                 −3.0057 
                   
                 (ASP) 
                 0.110 
               
               
                 6 
                 Lens 3 
                 1.7678 
                   
                 (ASP) 
                 0.210 
                 Plastic 
                 1.679 
                 18.4 
                 11.79 
               
               
                 7 
                   
                 2.1598 
                   
                 (ASP) 
                 0.322 
               
               
                 8 
                 Lens 4 
                 −37.1546 
                   
                 (ASP) 
                 0.837 
                 Plastic 
                 1.544 
                 56.0 
                 2.06 
               
               
                 9 
                   
                 −1.0988 
                   
                 (ASP) 
                 0.052 
               
               
                 10 
                 Lens 5 
                 1.2188 
                 1.2153 
                 (FFS) 
                 0.370 
                 Plastic 
                 1.669 
                 19.5 
                 −2.36 
                 −2.37 
               
               
                 11 
                   
                 0.6047 
                 0.6039 
                 (FFS) 
                 0.503 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 12 
                 Filter 
                 Plano 
                 0.145 
                 Glass 
                 1.517 
                 64.2 
                 — 
                   
               
               
                 13 
                   
                 Plano 
                 0.450 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm (d-line). 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 17 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Surface # 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k= 
                  −1.79449E+00 
                  2.92122E+00 
                 −2.02168E+01 
               
               
                 A4= 
                 −3.667368E−02 
                 −9.497570E−01  
                 −5.179238E−01  
               
               
                 A6= 
                 −2.929026E−01 
                 2.266038E+00 
                 3.069720E−01 
               
               
                 A8= 
                  7.880423E−01 
                 −4.761287E+00  
                 2.213953E−01 
               
               
                 A10= 
                 −3.289009E+00 
                 5.401242E+00 
                 −9.352031E−01  
               
               
                 A12= 
                  3.243497E+00 
                 −2.893552E+00  
                 5.170242E−01 
               
               
                 A14= 
                 — 
                 1.343134E−01 
                 −2.083082E−01  
               
               
                 A16= 
                 — 
                 2.104508E−01 
                 2.364709E−01 
               
               
                   
               
               
                 Surface # 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 k= 
                  −1.61651E+00 
                  0.00000E+00 
                 −3.00792E+00 
               
               
                 A4= 
                 −1.127813E−01 
                 4.198403E−01 
                 3.879409E−01 
               
               
                 A6= 
                 −9.522000E−01 
                 −1.105394E+00  
                 −9.495992E−01  
               
               
                 A8= 
                  3.555270E+00 
                 1.788292E+00 
                 1.279971E+00 
               
               
                 A10= 
                 −6.560436E+00 
                 −1.992334E+00  
                 −1.112410E+00  
               
               
                 A12= 
                  7.145479E+00 
                 1.538192E+00 
                 6.457292E−01 
               
               
                 A14= 
                 −4.668021E+00 
                 −7.929365E−01  
                 −2.397497E−01  
               
               
                 A16= 
                  1.700405E+00 
                 2.557512E−01 
                 5.290740E−02 
               
               
                 A18= 
                 −2.658507E−01 
                 −4.584922E−02  
                 −6.113765E−03  
               
               
                 A20= 
                 — 
                 3.370164E−03 
                 2.690291E−04 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 18 
               
               
                   
               
               
                 Freeform Coefficients 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface # 
                 1 
                 2 
                 Surface # 
                 1 
                 2 
               
               
                   
               
               
                 kx= 
                  0.00000E+00 
                  2.62227E−01 
                 ky= 
                  −6.04712E−07 
                  2.63457E−01 
               
               
                 Ax4= 
                  3.392984E−01 
                 6.320502E−01 
                 Ay4= 
                  3.391093E−01 
                 6.327905E−01 
               
               
                 Ax6= 
                 −3.289979E−01 
                 −2.578349E+00  
                 Ay6= 
                 −3.288146E−01 
                 −2.581369E+00  
               
               
                 Ax8= 
                  3.247016E−01 
                 2.218705E+01 
                 Ay8= 
                  3.245207E−01 
                 2.221304E+01 
               
               
                 Ax10= 
                 −2.741898E−01 
                 −1.223514E+02  
                 Ay10= 
                 −2.740369E−01 
                 −1.224947E+02  
               
               
                 Ax12= 
                  1.873229E−01 
                 4.196108E+02 
                 Ay12= 
                  1.872185E−01 
                 4.201023E+02 
               
               
                 Ax14= 
                 −9.516491E−02 
                 −9.184398E+02  
                 Ay14= 
                 −9.511187E−02 
                 −9.195155E+02  
               
               
                 Ax16= 
                  3.345427E−02 
                 1.299684E+03 
                 Ay16= 
                  3.343563E−02 
                 1.301206E+03 
               
               
                 Ax18= 
                 −7.564433E−03 
                 −1.173092E+03  
                 Ay18= 
                 −7.560217E−03 
                 −1.174466E+03  
               
               
                 Ax20= 
                  9.853132E−04 
                 6.447844E+02 
                 Ay20= 
                  9.847640E−04 
                 6.455396E+02 
               
               
                 Ax22= 
                 −5.698137E−05 
                 −1.943995E+02  
                 Ay22= 
                 −5.694961E−05 
                 −1.946271E+02  
               
               
                 Ax24= 
                 — 
                 2.434760E+01 
                 Ay24= 
                 — 
                 2.437612E+01 
               
               
                   
               
               
                 Surface # 
                 10 
                 11 
                 Surface # 
                 10 
                 11 
               
               
                   
               
               
                 kx= 
                 −5.44103E+00 
                  −3.85370E+00 
                 ky= 
                 −5.41662E+00 
                  −3.87359E+00 
               
               
                 Ax4= 
                 −2.956542E−01  
                 −2.707073E−01 
                 Ay4= 
                 −2.942804E−01  
                 −2.721480E−01 
               
               
                 Ax6= 
                 5.403643E−02 
                  2.824278E−01 
                 Ay6= 
                 5.378534E−02 
                  2.839309E−01 
               
               
                 Ax8= 
                 4.400365E−02 
                 −2.486729E−01 
                 Ay8= 
                 4.379918E−02 
                 −2.499963E−01 
               
               
                 Ax10= 
                 8.046954E−03 
                  1.715371E−01 
                 Ay10= 
                 8.009563E−03 
                  1.724500E−01 
               
               
                 Ax12= 
                 −3.706149E−02  
                 −8.686965E−02 
                 Ay12= 
                 −3.688928E−02  
                 −8.733197E−02 
               
               
                 Ax14= 
                 2.235342E−02 
                  3.140517E−02 
                 Ay14= 
                 2.224955E−02 
                  3.157231E−02 
               
               
                 Ax16= 
                 −6.566510E−03  
                 −8.007907E−03 
                 Ay16= 
                 −6.535998E−03  
                 −8.050525E−03 
               
               
                 Ax18= 
                 1.061092E−03 
                  1.419718E−03 
                 Ay18= 
                 1.056161E−03 
                  1.427273E−03 
               
               
                 Ax20= 
                 −9.026357E−05  
                 −1.703766E−04 
                 Ay20= 
                 −8.984415E−05  
                 −1.712833E−04 
               
               
                 Ax22= 
                 3.147198E−06 
                  1.314325E−05 
                 Ay22= 
                 3.132574E−06 
                  1.321320E−05 
               
               
                 Ax24= 
                 — 
                 −5.859787E−07 
                 Ay24= 
                 — 
                 −5.890972E−07 
               
               
                 Ax26= 
                 — 
                  1.143771E−08 
                 Ay26= 
                 — 
                  1.149858E−08 
               
               
                   
               
            
           
         
       
     
     In the 6th embodiment, the equations of the freeform surface profiles and the axisymmetric aspheric surface profiles of the aforementioned lens elements are the same as the equations of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 6th embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 16, Table 17 and Table 18 as the following values and satisfy the following conditions: 
     
       
         
           
               
             
               
                   
               
               
                 6th Embodiment 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 fD [mm] 
                 1.76 
                 T34/T23 
                 2.93 
               
               
                 fX [mm] 
                 1.76 
                 TL/f 
                 3.04 
               
               
                 fY [mm] 
                 1.76 
                 TL/ImgH 
                 1.82 
               
               
                 Fno 
                 2.35 
                 (R9 + R10)/(R9 − R10) 
                 2.97 
               
               
                 HFOVD [deg.] 
                 60.0 
                 R1/f 
                 −1.85 
               
               
                 HFOVX [deg.] 
                 53.2 
                 R1/f1 
                 0.84 
               
               
                 HFOVY [deg.] 
                 44.8 
                 R8/f 
                 −0.63 
               
               
                 ImgHD [mm] 
                 2.93 
                 f/f5 
                 −0.74 
               
               
                 ImgHX [mm] 
                 2.36 
                 f123/f 
                 1.78 
               
               
                 ImgHY [mm] 
                 1.75 
                 14/CT4 
                 2.47 
               
               
                 (V2 + V4)/V3 
                 6.07 
                 f45/f 
                 3.02 
               
               
                 (Vi/Ni) min 
                 10.98 
                 HFOV [deg.] 
                 60.0 
               
               
                 V3 + V5 
                 37.9 
                 Y52/Y11 
                 1.41 
               
               
                 (CT1 + CT2 + CT4)/ 
                 4.19 
                 |dSAG|max [um] 
                 0.60; 0.48; 
               
               
                 (CT3 + CT5) 
                   
                   
                 1.92; 3.64  
               
               
                 (CT2 + CT3 + CT4 + 
                 4.27 
                 |dSAG|max/CTF 
                 1.04E−03; 
               
               
                 CT5)/CT1 
                   
                   
                 8.34E−04; 
               
               
                   
                   
                   
                 5.19E−03; 
               
               
                   
                   
                   
                 9.83E−03  
               
               
                 CT1/CT4 
                 0.68 
                 — 
                 — 
               
               
                   
               
            
           
         
       
     
     7th Embodiment 
       FIG. 13  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 7th embodiment of the present disclosure.  FIG. 14  shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 7th embodiment. In  FIG. 13 , the image capturing unit includes the optical photographing lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor  780 . The optical photographing lens assembly includes, in order from an object side to an image side along an optical path, a first lens element  710 , an aperture stop  700 , a second lens element  720 , a third lens element  730 , a fourth lens element  740 , a fifth lens element  750 , a filter  760  and an image surface  770 . The optical photographing lens assembly includes five lens elements ( 710 ,  720 ,  730 ,  740  and  750 ) with no additional lens element disposed between each of the adjacent five lens elements. 
     The first lens element  710  with negative refractive power has an object-side surface  711  being concave in a paraxial region thereof and an image-side surface  712  being concave in a paraxial region thereof. The first lens element  710  is made of plastic material and has the object-side surface  711  and the image-side surface  712  being both freeform surfaces. The object-side surface  711  of the first lens element  710  has one critical point in an off-axis region thereof and in a maximum image height direction. 
     The second lens element  720  with positive refractive power has an object-side surface  721  being convex in a paraxial region thereof and an image-side surface  722  being convex in a paraxial region thereof. The second lens element  720  is made of plastic material and has the object-side surface  721  and the image-side surface  722  being both aspheric. 
     The third lens element  730  with positive refractive power has an object-side surface  731  being convex in a paraxial region thereof and an image-side surface  732  being concave in a paraxial region thereof. The third lens element  730  is made of plastic material and has the object-side surface  731  and the image-side surface  732  being both aspheric. 
     The fourth lens element  740  with positive refractive power has an object-side surface  741  being convex in a paraxial region thereof and an image-side surface  742  being convex in a paraxial region thereof. The fourth lens element  740  is made of plastic material and has the object-side surface  741  and the image-side surface  742  being both aspheric. 
     The fifth lens element  750  with negative refractive power has an object-side surface  751  being convex in a paraxial region thereof and an image-side surface  752  being concave in a paraxial region thereof. The fifth lens element  750  is made of plastic material and has the object-side surface  751  and the image-side surface  752  being both aspheric. The object-side surface  751  of the fifth lens element  750  has one critical point in an off-axis region thereof and in the maximum image height direction. The image-side surface  752  of the fifth lens element  750  has one critical point in an off-axis region thereof and in the maximum image height direction. 
     The filter  760  is made of glass material and located between the fifth lens element  750  and the image surface  770 , and will not affect the focal length of the optical photographing lens assembly. The image sensor  780  is disposed on or near the image surface  770  of the optical photographing lens assembly. 
     In this embodiment, the maximum image height direction corresponds to a diagonal direction D of a photosensitive area of the image sensor  780 . 
     In this embodiment, the object-side surface  711  of the first lens element  710  satisfies the following conditions: |dSAG|max=0.67 um; and |dSAG|max/CTF=1.22E-03. The image-side surface  712  of the first lens element  710  satisfies the following conditions: |dSAG|max=0.77 um; and |dSAG|max/CTF=1.40E-03. 
     The detailed optical data of the 7th embodiment are shown in Table 19, the aspheric surface data are shown in Table 20 and the freeform surface data are shown in Table 21 below. 
     
       
         
           
               
             
               
                 TABLE 19 
               
             
            
               
                   
               
               
                 7th Embodiment 
               
               
                 fD = 1.77 mm, fX = 1.77 mm, fY = 1.77 mm, Fno = 2.37 
               
               
                 HFOVD = 60.0 deg., HFOVX = 53.1 deg., HFOVY = 44.5 deg. 
               
               
                 ImgHD = 2.93 mm, ImgHX = 2.36 mm, ImgHY = 1.75 mm 
               
            
           
           
               
               
               
               
            
               
                   
                 Curvature Radius 
                   
                 Focal Length 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Surface # 
                   
                 (Y-dir.) 
                 (X-dir.) 
                   
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 (Y-dir.) 
                 (X-dir.) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                 Lens 1 
                 −3.3504 
                 −3.3469 
                 (FFS) 
                 0.550 
                 Plastic 
                 1.545 
                 56.1 
                 −3.92 
                 −3.91 
               
               
                 2 
                   
                 6.2523 
                 6.2190 
                 (FFS) 
                 0.807 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 3 
                 Ape. Stop 
                 Plano 
                 −0.013  
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 4 
                 Lens 2 
                 3.1254 
                   
                 (ASP) 
                 1.008 
                 Plastic 
                 1.544 
                 56.0 
                 2.74 
                   
               
               
                 5 
                   
                 −2.5334 
                   
                 (ASP) 
                 0.115 
               
               
                 6 
                 Lens 3 
                 1.7586 
                   
                 (ASP) 
                 0.210 
                 Plastic 
                 1.686 
                 18.4 
                 16.48 
               
               
                 7 
                   
                 1.9812 
                   
                 (ASP) 
                 0.391 
               
               
                 8 
                 Lens 4 
                 111.0982 
                   
                 (ASP) 
                 0.797 
                 Plastic 
                 1.544 
                 56.0 
                 2.21 
               
               
                 9 
                   
                 −1.2150 
                   
                 (ASP) 
                 0.041 
               
               
                 10 
                 Lens 5 
                 1.0855 
                   
                 (ASP) 
                 0.344 
                 Plastic 
                 1.669 
                 19.5 
                 −2.58 
               
               
                 11 
                   
                 0.5818 
                   
                 (ASP) 
                 0.545 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 12 
                 Filter 
                 Plano 
                 0.210 
                 Glass 
                 1.517 
                 64.2 
                 — 
                   
               
               
                 13 
                   
                 Plano 
                 0.364 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm (d-line). 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 20 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 Surface # 
                 4 
                 5 
                 6 
                 7 
               
               
                   
               
               
                 k= 
                  −8.90474E+00 
                  2.12164E+00 
                  −1.22783E+01 
                  −1.46285E+00 
               
               
                 A4= 
                 −3.400840E−02 
                 −8.070886E−01 
                 −6.006626E−01 
                 −1.787146E−01 
               
               
                 A6= 
                 −1.977790E−01 
                  1.669408E+00 
                  1.213336E+00 
                 −3.395621E−01 
               
               
                 A8= 
                 −6.516948E−02 
                 −3.170313E+00 
                 −3.847671E+00 
                  1.240727E+00 
               
               
                 A10= 
                 −5.420333E−01 
                  2.942922E+00 
                  8.721966E+00 
                 −1.887365E+00 
               
               
                 A12= 
                 −3.693910E−02 
                 −7.089547E−01 
                 −1.228330E+01 
                  1.574488E+00 
               
               
                 A14= 
                 — 
                 −8.907479E−01 
                  8.968838E+00 
                 −7.198113E−01 
               
               
                 A16= 
                 — 
                  4.018270E−01 
                 −2.532072E+00 
                  1.600667E−01 
               
               
                 A18= 
                 — 
                 — 
                 — 
                 −1.073377E−02 
               
               
                   
               
               
                 Surface # 
                 8 
                 9 
                 10 
                 11 
               
               
                   
               
               
                 k= 
                  0.00000E+00 
                 −2.84290E+00 
                  −5.42960E+00 
                  −3.56687E+00 
               
               
                 A4= 
                 2.908436E−01 
                 3.640175E−01 
                 −2.707182E−01 
                 −2.837953E−01 
               
               
                 A6= 
                 −7.068783E−01  
                 −8.598820E−01  
                  1.548704E−02 
                  2.913627E−01 
               
               
                 A8= 
                 1.017378E+00 
                 1.110561E+00 
                  9.153551E−02 
                 −2.411785E−01 
               
               
                 A10= 
                 −9.907189E−01  
                 −9.280479E−01  
                 −3.898111E−02 
                  1.541401E−01 
               
               
                 A12= 
                 6.731674E−01 
                 5.311251E−01 
                 −6.268229E−03 
                 −7.256439E−02 
               
               
                 A14= 
                 −3.102320E−01  
                 −1.995056E−01  
                  9.760303E−03 
                  2.448857E−02 
               
               
                 A16= 
                 9.086540E−02 
                 4.551198E−02 
                 −3.389450E−03 
                 −5.834637E−03 
               
               
                 A18= 
                 −1.505522E−02  
                 −5.585180E−03  
                  5.815054E−04 
                  9.651628E−04 
               
               
                 A20= 
                 1.037014E−03 
                 2.755482E−04 
                 −5.068046E−05 
                 −1.078281E−04 
               
               
                 A22= 
                 — 
                 — 
                  1.780658E−06 
                  7.734380E−06 
               
               
                 A24= 
                 — 
                 — 
                 — 
                 −3.213099E−07 
               
               
                 A26= 
                 — 
                 — 
                 — 
                  5.893861E−09 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 21 
               
             
            
               
                   
               
               
                 Freeform Coefficients 
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface # 
                 1 
                 2 
                 Surface # 
                 1 
                 2 
               
               
                   
               
               
                 kx= 
                  0.00000E+00 
                  2.26662E+01 
                 ky= 
                  −8.68665E−07 
                  2.25300E+01 
               
               
                 Ax4= 
                  3.164081E−01 
                  4.441002E−01 
                 Ay4= 
                  3.165979E−01 
                  4.436628E−01 
               
               
                 Ax6= 
                 −2.718875E−01 
                 −4.160441E−01 
                 Ay6= 
                 −2.720506E−01 
                 −4.156344E−01 
               
               
                 Ax8= 
                  2.403377E−01 
                  3.961233E+00 
                 Ay8= 
                  2.404819E−01 
                  3.957331E+00 
               
               
                 Ax10= 
                 −1.952757E−01 
                 −2.496569E+01 
                 Ay10= 
                 −1.953928E−01 
                 −2.494110E+01 
               
               
                 Ax12= 
                  1.409030E−01 
                  8.351660E+01 
                 Ay12= 
                  1.409875E−01 
                  8.343434E+01 
               
               
                 Ax14= 
                 −7.944048E−02 
                 −1.565976E+02 
                 Ay14= 
                 −7.948813E−02 
                 −1.564433E+02 
               
               
                 Ax16= 
                  3.135748E−02 
                  1.599240E+02 
                 Ay16= 
                  3.137629E−02 
                  1.597665E+02 
               
               
                 Ax18= 
                 −7.938500E−03 
                 −6.458571E+01 
                 Ay18= 
                 −7.943261E−03 
                 −6.452209E+01 
               
               
                 Ax20= 
                  1.148276E−03 
                 −2.579676E+01 
                 Ay20= 
                  1.148964E−03 
                 −2.577135E+01 
               
               
                 Ax22= 
                 −7.256498E−05 
                  3.374000E+01 
                 Ay22= 
                 −7.260850E−05 
                  3.370676E+01 
               
               
                 Ax24= 
                 — 
                 −8.873807E+00 
                 Ay24= 
                 — 
                 −8.865067E+00 
               
               
                   
               
            
           
         
       
     
     In the 7th embodiment, the equations of the freeform surface profiles and the axisymmetric aspheric surface profiles of the aforementioned lens elements are the same as the equations of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 7th embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 19, Table 20 and Table 21 as the following values and satisfy the following conditions: 
     
       
         
           
               
             
               
                   
               
               
                 7th Embodiment 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 fD [mm] 
                 1.77 
                 T34/T23 
                 3.40 
               
               
                 fX [mm] 
                 1.77 
                 TL/f 
                 3.04 
               
               
                 fY [mm] 
                 1.77 
                 TL/ImgH 
                 1.83 
               
               
                 Fno 
                 2.37 
                 (R9 + R10)/(R9 − R10) 
                 3.31 
               
               
                 HFOVD [deg.] 
                 60.0 
                 R1/f 
                 −1.89 
               
               
                 HFOVX [deg.] 
                 53.1 
                 R1/f1 
                 0.85 
               
               
                 HFOVY [deg.] 
                 44.5 
                 R8/f 
                 −0.69 
               
               
                 ImgHD [mm] 
                 2.93 
                 f/f5 
                 −0.68 
               
               
                 ImgHX [mm] 
                 2.36 
                 f 123/f 
                 1.73 
               
               
                 ImgHY [mm] 
                 1.75 
                 f4/CT4 
                 2.78 
               
               
                 (V2 + V4)/V3 
                 6.09 
                 f45/f 
                 3.16 
               
               
                 (Vi/Ni) min 
                 10.90 
                 HFOV [deg.] 
                 60.0 
               
               
                 V3 + V5 
                 37.8 
                 Y52/Y11 
                 1.44 
               
               
                 (CT1 + CT2 + CT4)/ 
                 4.25 
                 |dSAG|max [um] 
                 0.67; 0.77 
               
               
                 (CT3 + CT5) 
               
               
                 (CT2 + CT3 + CT4 + 
                 4.29 
                 |dSAG|max/CTF 
                 1.22E−03; 
               
               
                 CT5)/CT1 
                   
                   
                 1.40E−03  
               
               
                 CT1/CT4 
                 0.69 
                 — 
                 — 
               
               
                   
               
            
           
         
       
     
     8th Embodiment 
       FIG. 15  is a cross-sectional view of an image capturing unit corresponding to a diagonal direction of a photosensitive area of an image sensor according to the 8th embodiment of the present disclosure.  FIG. 16  shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 8th embodiment. In  FIG. 15 , the image capturing unit includes the optical photographing lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor  880 . The optical photographing lens assembly includes, in order from an object side to an image side along an optical path, a first lens element  810 , an aperture stop  800 , a second lens element  820 , a third lens element  830 , a fourth lens element  840 , a fifth lens element  850 , a filter  860  and an image surface  870 . The optical photographing lens assembly includes five lens elements ( 810 ,  820 ,  830 ,  840  and  850 ) with no additional lens element disposed between each of the adjacent five lens elements. 
     The first lens element  810  with negative refractive power has an object-side surface  811  being concave in a paraxial region thereof and an image-side surface  812  being convex in a paraxial region thereof. The first lens element  810  is made of plastic material and has the object-side surface  811  being a freeform surface and the image-side surface  812  being aspheric. The object-side surface  811  of the first lens element  810  has one critical point in an off-axis region thereof and in a maximum image height direction. 
     The second lens element  820  with positive refractive power has an object-side surface  821  being convex in a paraxial region thereof and an image-side surface  822  being convex in a paraxial region thereof. The second lens element  820  is made of plastic material and has the object-side surface  821  and the image-side surface  822  being both aspheric. 
     The third lens element  830  with negative refractive power has an object-side surface  831  being concave in a paraxial region thereof and an image-side surface  832  being concave in a paraxial region thereof. The third lens element  830  is made of plastic material and has the object-side surface  831  and the image-side surface  832  being both aspheric. 
     The fourth lens element  840  with positive refractive power has an object-side surface  841  being convex in a paraxial region thereof and an image-side surface  842  being convex in a paraxial region thereof. The fourth lens element  840  is made of plastic material and has the object-side surface  841  and the image-side surface  842  being both aspheric. 
     The fifth lens element  850  with negative refractive power has an object-side surface  851  being convex in a paraxial region thereof and an image-side surface  852  being concave in a paraxial region thereof. The fifth lens element  850  is made of plastic material and has the object-side surface  851  and the image-side surface  852  being both aspheric. The object-side surface  851  of the fifth lens element  850  has two critical points in an off-axis region thereof and in the maximum image height direction. The image-side surface  852  of the fifth lens element  850  has one critical point in an off-axis region thereof and in the maximum image height direction. 
     The filter  860  is made of glass material and located between the fifth lens element  850  and the image surface  870 , and will not affect the focal length of the optical photographing lens assembly. The image sensor  880  is disposed on or near the image surface  870  of the optical photographing lens assembly. 
     In this embodiment, the maximum image height direction corresponds to a diagonal direction D of a photosensitive area of the image sensor  880 . 
     In this embodiment, the object-side surface  811  of the first lens element  810  satisfies the following conditions: |dSAG|max=0.92 um; and |dSAG|max/CTF=1.41 E-03. 
     The detailed optical data of the 8th embodiment are shown in Table 22, the aspheric surface data are shown in Table 23 and the freeform surface data are shown in Table 24 below. 
     
       
         
           
               
             
               
                 TABLE 22 
               
             
            
               
                   
               
               
                 8th Embodiment 
               
               
                 fD = 1.89 mm, fX = 1.89 mm, fY = 1.89 mm, Fno = 2.49 
               
               
                 HFOVD = 57.2 deg., HFOVX = 51.2 deg., HFOVY = 43.0 deg. 
               
               
                 ImgHD = 2.93 mm, ImgHX = 2.36 mm, ImgHY = 1.75 mm 
               
            
           
           
               
               
               
               
            
               
                   
                 Curvature Radius 
                   
                 Focal Length 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Surface # 
                   
                 (Y-dir.) 
                 (X-dir.) 
                   
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 (Y-dir.) 
                 (X-dir.) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                 Lens 1 
                 −2.4599 
                 −2.4622 
                 (FFS) 
                 0.655 
                 Plastic 
                 1.529 
                 58.0 
                 −4.71 
                 −4.72 
               
               
                 2 
                   
                 −200.0000 
                   
                 (ASP) 
                 0.900 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 3 
                 Ape. Stop 
                 Plano 
                 −0.030  
                   
                   
                   
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 4 
                 Lens 2 
                 2.6932 
                   
                 (ASP) 
                 0.874 
                 Plastic 
                 1.562 
                 44.6 
                 2.08 
                   
               
               
                 5 
                   
                 −1.8190 
                   
                 (ASP) 
                 0.213 
               
               
                 6 
                 Lens 3 
                 −200.0000 
                   
                 (ASP) 
                 0.250 
                 Plastic 
                 1.701 
                 14.8 
                 −7.90 
               
               
                 7 
                   
                 5.6999 
                   
                 (ASP) 
                 0.363 
               
               
                 8 
                 Lens 4 
                 4.8299 
                   
                 (ASP) 
                 0.773 
                 Plastic 
                 1.529 
                 58.0 
                 2.21 
               
               
                 9 
                   
                 −1.4531 
                   
                 (ASP) 
                 0.020 
               
               
                 10 
                 Lens 5 
                 1.2388 
                   
                 (ASP) 
                 0.334 
                 Plastic 
                 1.669 
                 19.5 
                 −2.46 
               
               
                 11 
                   
                 0.6307 
                   
                 (ASP) 
                 0.511 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 12 
                 Filter 
                 Plano 
                 0.210 
                 Glass 
                 1.517 
                 64.2 
                 — 
                   
               
               
                 13 
                   
                 Plano 
                 0.397 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm (d-line). 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 23 
               
               
                   
               
               
                 Aspheric Coefficients 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface # 
                 2 
                 4 
                 5 
                 6 
                 7 
               
               
                   
               
               
                 k= 
                  9.90000E+01 
                  0.00000E+00 
                  2.53398E−01 
                  −9.90000E+01 
                  7.48817E+00 
               
               
                 A4= 
                 4.648345E−01 
                 −9.304066E−02 
                 −2.461612E−01 
                 −3.638513E−01 
                 −1.906423E−01 
               
               
                 A6= 
                 −5.302735E−01  
                  1.493272E+00 
                  5.678366E−01 
                  8.772600E−01 
                  3.572417E−01 
               
               
                 A8= 
                 6.238317E−01 
                 −3.108028E+01 
                 −2.510941E+00 
                 −1.468467E+00 
                 −1.720837E−01 
               
               
                 A10= 
                 3.911197E+00 
                  3.519352E+02 
                  5.357138E+00 
                 −1.854609E−01 
                 −5.108095E−01 
               
               
                 A12= 
                 −2.798571E+01  
                 −2.485256E+03 
                 −7.984179E+00 
                  3.478371E+00 
                  9.489200E−01 
               
               
                 A14= 
                 8.676022E+01 
                  1.088275E+04 
                  7.276800E+00 
                 −5.117859E+00 
                 −7.292914E−01 
               
               
                 A16= 
                 −1.545439E+02  
                 −2.856701E+04 
                 −3.255665E+00 
                  2.479149E+00 
                  2.858036E−01 
               
               
                 A18= 
                 1.669491E+02 
                  4.075735E+04 
                 — 
                 — 
                 −4.732189E−02 
               
               
                 A20= 
                 −1.074984E+02  
                 −2.404562E+04 
                 — 
                 — 
                 — 
               
               
                 A22= 
                 3.774452E+01 
                 — 
                 — 
                 — 
                 — 
               
               
                 A24= 
                 −5.536324E+00  
                 — 
                 — 
                 — 
                 — 
               
               
                   
               
               
                 Surface # 
                 8 
                 9 
                 10 
                 11 
                 — 
               
               
                   
               
               
                 k= 
                  0.00000E+00 
                  −9.34502E+00 
                  −7.57345E+00 
                  −4.02670E+00 
                 — 
               
               
                 A4= 
                 2.166773E−01 
                  3.878815E−01 
                 −1.176440E−01 
                 −2.006742E−01 
                 — 
               
               
                 A6= 
                 −4.467608E−01  
                 −5.755821E−01 
                 −9.573180E−02 
                  1.715284E−01 
                 — 
               
               
                 A8= 
                 4.842987E−01 
                  4.722054E−01 
                  8.925726E−02 
                 −1.746883E−01 
                 — 
               
               
                 A10= 
                 −3.532668E−01  
                 −2.798040E−01 
                 −1.889275E−02 
                  1.476445E−01 
                 — 
               
               
                 A12= 
                 1.764496E−01 
                  1.271686E−01 
                 −3.623223E−03 
                 −8.648609E−02 
                 — 
               
               
                 A14= 
                 −5.773122E−02  
                 −4.151107E−02 
                  2.610406E−03 
                  3.441112E−02 
                 — 
               
               
                 A16= 
                 1.118832E−02 
                  9.034741E−03 
                 −5.727229E−04 
                 −9.333916E−03 
                 — 
               
               
                 A18= 
                 −1.014863E−03  
                 −1.230768E−03 
                  6.459343E−05 
                  1.719432E−03 
                 — 
               
               
                 A20= 
                 1.181830E−05 
                  9.499572E−05 
                 −3.775073E−06 
                 −2.109000E−04 
                 — 
               
               
                 A22= 
                 — 
                 −3.181332E−06 
                  9.039513E−08 
                  1.643633E−05 
                 — 
               
               
                 A24= 
                 — 
                 — 
                 — 
                 −7.341567E−07 
                 — 
               
               
                 A26= 
                 — 
                 — 
                 — 
                  1.426450E−08 
                 — 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 24 
               
             
            
               
                   
               
               
                 Freeform Coefficients 
               
            
           
           
               
               
               
               
            
               
                 Surface # 
                 1 
                 Surface # 
                 1 
               
               
                   
               
               
                 kx= 
                  0.00000E+00 
                 ky= 
                  −6.67649E−07 
               
               
                 Ax4= 
                  3.180910E−01 
                 Ay4= 
                  3.179380E−01 
               
               
                 Ax6= 
                 −3.148118E−01 
                 Ay6= 
                 −3.146603E−01 
               
               
                 Ax8= 
                  3.258397E−01 
                 Ay8= 
                  3.256829E−01 
               
               
                 Ax10= 
                 −2.724487E−01 
                 Ay10= 
                 −2.723177E−01 
               
               
                 Ax12= 
                  1.704985E−01 
                 Ay12= 
                  1.704165E−01 
               
               
                 Ax14= 
                 −7.582088E−02 
                 Ay14= 
                 −7.578439E−02 
               
               
                 Ax16= 
                  2.298780E−02 
                 Ay16= 
                  2.297674E−02 
               
               
                 Ax18= 
                 −4.491561E−03 
                 Ay18= 
                 −4.489399E−03 
               
               
                 Ax20= 
                  5.084768E−04 
                 Ay20= 
                  5.082322E−04 
               
               
                 Ax22= 
                 −2.534988E−05 
                 Ay22= 
                 −2.533768E−05 
               
               
                   
               
            
           
         
       
     
     In the 8th embodiment, the equations of the freeform surface profiles and the axisymmetric aspheric surface profiles of the aforementioned lens elements are the same as the equations of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 8th embodiment, so an explanation in this regard will not be provided again. 
     Moreover, these parameters can be calculated from Table 22, Table 23 and Table 24 as the following values and satisfy the following conditions: 
     
       
         
           
               
             
               
                   
               
               
                 8th Embodiment 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 fD [mm] 
                 1.89 
                 T34/T23 
                 1.70 
               
               
                 fX [mm] 
                 1.89 
                 TL/f 
                 2.89 
               
               
                 fY [mm] 
                 1.89 
                 TL/ImgH 
                 1.86 
               
               
                 Fno 
                 2.49 
                 (R9 + R10)/(R9 − R10) 
                 3.07 
               
               
                 HFOVD [deg.] 
                 57.2 
                 R1/f 
                 −1.30 
               
               
                 HFOVX [deg.] 
                 51.2 
                 R1/f1 
                 0.52 
               
               
                 HFOVY [deg.] 
                 43.0 
                 R8/f 
                 −0.77 
               
               
                 ImgHD [mm] 
                 2.93 
                 f/f5 
                 −0.77 
               
               
                 ImgHX [mm] 
                 2.36 
                 f123/f 
                 1.75 
               
               
                 ImgHY [mm] 
                 1.75 
                 f4/CT4 
                 2.85 
               
               
                 (V2 + V4)/V3 
                 6.93 
                 f45/f 
                 3.11 
               
               
                 (Vi/Ni) min 
                 8.70 
                 HFOV [deg.] 
                 57.2 
               
               
                 V3 + V5 
                 34.3 
                 Y52/Y11 
                 1.30 
               
               
                 (CT1 + CT2 + CT4)/ 
                 3.94 
                 |dSAG|max [um] 
                 0.92 
               
               
                 (CT3 + CT5) 
               
               
                 (CT2 + CT3 + CT4 + 
                 3.41 
                 |dSAG|max/CTF 
                 1.41E−03 
               
               
                 CT5)/CT1 
               
               
                 CT1/CT4 
                 0.85 
                 — 
                 — 
               
               
                   
               
            
           
         
       
     
     9th Embodiment 
       FIG. 17  is a perspective view of an image capturing unit according to the 9th embodiment of the present disclosure. In this embodiment, an image capturing unit is a camera module including a lens unit  11 , a driving device  12 , an image sensor  13  and an image stabilizer  14 . The lens unit  11  includes the optical photographing lens assembly disclosed in the 1st embodiment, a barrel and a holder member (their reference numerals are omitted) for holding the optical photographing lens assembly. However, the lens unit  11  may alternatively be provided with the optical photographing lens assembly disclosed in other embodiments of the present disclosure, and the present disclosure is not limited thereto. The imaging light converges in the lens unit  11  of the image capturing unit to generate an image with the driving device  12  utilized for image focusing on the image sensor  13 , and the generated image is then digitally transmitted to other electronic component for further processing. 
     The driving device  12  can have auto focusing functionality, and different driving configurations can be obtained through the usages of voice coil motors (VCM), micro electro-mechanical systems (MEMS), piezoelectric systems, or shape memory alloy materials. The driving device  12  is favorable for obtaining a better imaging position of the lens unit  11 , so that a clear image of the imaged object can be captured by the lens unit  11  with different object distances. The image sensor  13  (for example, CCD or CMOS), which can feature high photosensitivity and low noise, is disposed on the image surface of the optical photographing lens assembly to provide higher image quality. 
     The image stabilizer  14 , such as an accelerometer, a gyro sensor and a Hall Effect sensor, is configured to work with the driving device  12  to provide optical image stabilization (OIS). The driving device  12  working with the image stabilizer  14  is favorable for compensating for pan and tilt of the lens unit  11  to reduce blurring associated with motion during exposure. In some cases, the compensation can be provided by electronic image stabilization (EIS) with image processing software, thereby improving image quality while in motion or low-light conditions. 
     10th Embodiment 
       FIG. 18  is one perspective view of an electronic device according to the 10th embodiment of the present disclosure.  FIG. 19  is another perspective view of the electronic device in  FIG. 18 .  FIG. 20  is a block diagram of the electronic device in  FIG. 18 . 
     In this embodiment, an electronic device  20  is a smartphone including the image capturing unit  10  disclosed in the 9th embodiment, an image capturing unit  10   a , an image capturing unit  10   b , an image capturing unit  10   c , an image capturing unit  10   d , a flash module  21 , a focus assist module  22 , an image signal processor  23 , a display module  24  and an image software processor  25 . The image capturing unit  10  and the image capturing unit  10   a  are disposed on the same side of the electronic device  20  and each of the image capturing units  10  and  10   a  has a single focal point. The image capturing unit  10   b , the image capturing unit  10   c , the image capturing unit  10   d  and the display module  24  are disposed on the opposite side of the electronic device  20 , and the display module  24  can be a user interface, such that the image capturing units  10   b ,  10   c ,  10   d  can be front-facing cameras of the electronic device  20  for taking selfies, but the present disclosure is not limited thereto. Furthermore, each of the image capturing units  10   a ,  10   b ,  10   c  and  10   d  can include the optical photographing lens assembly of the present disclosure and can have a configuration similar to that of the image capturing unit  10 . In detail, each of the image capturing units  10   a ,  10   b ,  10   c  and  10   d  can include a lens unit, a driving device, an image sensor and an image stabilizer, and each of the lens unit can include an optical lens assembly such as the optical photographing lens assembly of the present disclosure, a barrel and a holder member for holding the optical lens assembly. 
     The image capturing unit  10  is a wide-angle image capturing unit, the image capturing unit  10   a  is an ultra-wide-angle image capturing unit, the image capturing unit  10   b  is a wide-angle image capturing unit, the image capturing unit  10   c  is an ultra-wide-angle image capturing unit, and the image capturing unit  10   d  is a ToF (time of flight) image capturing unit. In this embodiment, the image capturing units  10 ,  10   a ,  10   b  and  10   c  have different fields of view, such that the electronic device can have various magnification ratios so as to meet the requirement of optical zoom functionality. In addition, the image capturing unit  10   d  can determine depth information of the imaged object. In this embodiment, the electronic device  20  includes multiple image capturing units  10 ,  10   a ,  10   b ,  10   c  and  10   d , but the present disclosure is not limited to the number and arrangement of image capturing units. 
     When a user captures images of an object  26 , the light rays converge in the image capturing unit  10  or the image capturing unit  10   a  to generate images, and the flash module  21  is activated for light supplement. The focus assist module  22  detects the object distance of the imaged object  26  to achieve fast auto focusing. 
     The image signal processor  23  is configured to optimize the captured image to improve image quality. The light beam emitted from the focus assist module  22  can be either conventional infrared or laser. In addition, the light rays may converge in the image capturing unit  10   b ,  10   c  or  10   d  to generate images. The display module  24  can include a touch screen, and the user is able to interact with the display module  24  and the image software processor  25  having multiple functions to capture images and complete image processing. Alternatively, the user may capture images via a physical button. The image processed by the image software processor  25  can be displayed on the display module  24 . 
     11th Embodiment 
       FIG. 21  is one perspective view of an electronic device according to the 11th embodiment of the present disclosure. 
     In this embodiment, an electronic device  30  is a smartphone including the image capturing unit  10  disclosed in the 9th embodiment, an image capturing unit  10   e , an image capturing unit  10   f , a flash module  31 , a focus assist module, an image signal processor, a display module and an image software processor (not shown). The image capturing unit  10 , the image capturing unit  10   e  and the image capturing unit  10   f  are disposed on the same side of the electronic device  30 , while the display module is disposed on the opposite side of the electronic device  30 . Furthermore, each of the image capturing units  10   e  and  10   f  can include the optical photographing lens assembly of the present disclosure and can have a configuration similar to that of the image capturing unit  10 , and the details in this regard will not be provided again. 
     The image capturing unit  10  is a wide-angle image capturing unit, the image capturing unit  10   e  is a telephoto image capturing unit, and the image capturing unit  10   f  is an ultra-wide-angle image capturing unit. In this embodiment, the image capturing units  10 ,  10   e  and  10   f  have different fields of view, such that the electronic device  30  can have various magnification ratios so as to meet the requirement of optical zoom functionality. Moreover, the image capturing unit  10   e  can be a telephoto image capturing unit having a light-folding element configuration, such that the total track length of the image capturing unit  10   e  is not limited by the thickness of the electronic device  30 . Moreover, the light-folding element configuration of the image capturing unit  10   e  can be similar to, for example, one of the structures shown in  FIG. 30  to  FIG. 32 , which can be referred to foregoing descriptions corresponding to  FIG. 30  to  FIG. 32 , and the details in this regard will not be provided again. In this embodiment, the electronic device  30  includes multiple image capturing units  10 ,  10   e  and  10   f , but the present disclosure is not limited to the number and arrangement of image capturing units. When a user captures images of an object, light rays converge in the image capturing unit  10 ,  10   e  or  10   f  to generate images, and the flash module  31  is activated for light supplement. Further, the subsequent processes are performed in a manner similar to the abovementioned embodiment, so the details in this regard will not be provided again. 
     12th Embodiment 
       FIG. 22  is one perspective view of an electronic device according to the 12th embodiment of the present disclosure. 
     In this embodiment, an electronic device  40  is a smartphone including the image capturing unit  10  disclosed in the 9th embodiment, an image capturing unit  10   g , an image capturing unit  10   h , an image capturing unit  10   i , an image capturing unit  10   j , an image capturing unit  10   k , an image capturing unit  10   m , an image capturing unit  10   n , an image capturing unit  10   p , a flash module  41 , a focus assist module, an image signal processor, a display module and an image software processor (not shown). The image capturing units  10 ,  10   g ,  10   h ,  10   i ,  10   j ,  10   k ,  10   m ,  10   n  and  10   p  are disposed on the same side of the electronic device  40 , while the display module is disposed on the opposite side of the electronic device  40 . 
     Furthermore, each of the image capturing units  10   g ,  10   h ,  10   i ,  10   j ,  10   k ,  10   m ,  10   n  and  10   p  can include the optical photographing lens assembly of the present disclosure and can have a configuration similar to that of the image capturing unit  10 , and the details in this regard will not be provided again. 
     The image capturing unit  10  is a wide-angle image capturing unit, the image capturing unit  10   g  is a telephoto image capturing unit, the image capturing unit  10   h  is a telephoto image capturing unit, the image capturing unit  10   i  is a wide-angle image capturing unit, the image capturing unit  10   j  is an ultra-wide-angle image capturing unit, the image capturing unit  10   k  is an ultra-wide-angle image capturing unit, the image capturing unit  10   m  is a telephoto image capturing unit, the image capturing unit  10   n  is a telephoto image capturing unit, and the image capturing unit  10   p  is a ToF image capturing unit. In this embodiment, the image capturing units  10 ,  10   g ,  10   h ,  10   i ,  10   j ,  10   k ,  10   m  and  10   n  have different fields of view, such that the electronic device  40  can have various magnification ratios so as to meet the requirement of optical zoom functionality. Moreover, each of the image capturing units  10   g  and  10   h  can be a telephoto image capturing unit having a light-folding element configuration. Moreover, the light-folding element configuration of each of the image capturing unit  10   g  and  10   h  can be similar to, for example, one of the structures shown in  FIG. 30  to  FIG. 32 , which can be referred to foregoing descriptions corresponding to  FIG. 30  to  FIG. 32 , and the details in this regard will not be provided again. In addition, the image capturing unit  10   p  can determine depth information of the imaged object. In this embodiment, the electronic device  40  includes multiple image capturing units  10 ,  10   g ,  10   h ,  10   i ,  10   j ,  10   k ,  10   m ,  10   n  and  10   p , but the present disclosure is not limited to the number and arrangement of image capturing units. When a user captures images of an object, the light rays converge in the image capturing unit  10 ,  10   g ,  10   h ,  10   i ,  10   j ,  10   k ,  10   m ,  10   n  or  10   p  to generate images, and the flash module  41  is activated for light supplement. Further, the subsequent processes are performed in a manner similar to the abovementioned embodiments, and the details in this regard will not be provided again. 
     The smartphone in this embodiment is only exemplary for showing the image capturing unit  10  of the present disclosure installed in an electronic device, and the present disclosure is not limited thereto. The image capturing unit  10  can be optionally applied to optical systems with a movable focus. Furthermore, the optical photographing lens assembly of the image capturing unit  10  features good capability in aberration corrections and high image quality, and can be applied to 3D (three-dimensional) image capturing applications, in products such as digital cameras, mobile devices, digital tablets, smart televisions, network surveillance devices, dashboard cameras, vehicle backup cameras, multi-camera devices, image recognition systems, motion sensing input devices, wearable devices and other electronic imaging devices. 
     The foregoing description, for the purpose of explanation, has been described with reference to specific embodiments. It is to be noted that TABLES 1-24 show different data of the different embodiments; however, the data of the different embodiments are obtained from experiments. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, to thereby enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated. The embodiments depicted above and the appended drawings are exemplary and are not intended to be exhaustive or to limit the scope of the present disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings.