Patent Publication Number: US-9841538-B2

Title: Anamorphic objective zoom lens

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation in part of copending application Ser. No. 14/683,297 filed Apr. 10, 2015, which is a continuation is part of copending application Ser. No. 14/218,064, filed Mar. 18, 2014, which application claims the benefit under 37 CFR §119(e) of U.S. Provisional Application No. 61/808,343 filed Apr. 4, 2013, the contents of which are incorporated herein their entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     REFERENCE TO A “SEQUENCE LISTING”, A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON COMPACT DISC 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to anamorphic objective zoom lenses, and more particularly to a range of different focal length anamorphic objective zoom lenses with zoom ratios that provide imaging over wide to narrow fields of view and provide traditional anamorphic imaging characteristics, and potentially compact diameter by having an arrangement of five lens groups with spherical, anamorphic and spherical powers, in which one of the spherical lens groups following the anamorphic lens group has variable power and an optical stop located inside the last spherical lens group. 
     2. Description of Prior Art Including Information Disclosed Under 37 CFR 1.97 and 1.98 
     Contemporary anamorphic objective zoom lenses normally have an optical axis and are commonly based on a rear anamorphic lens group or a front anamorphic lens group. Anamorphic objective zoom lenses having a rear anamorphic lens group are typically more commonplace than anamorphic objective zoom lenses having a front anamorphic lens group. 
     Anamorphic objective zoom lenses having a rear anamorphic lens group have a rear lens group with Y cylinder refractive optical surfaces and a front spherical lens group with an optical stop in the front spherical lens group in the form of a variable aperture diameter iris or diaphragm. 
     This anamorphic objective zoom lens arrangement produces images having spherical out of focus objects commonly referred to as the bokeh as compared to the oval or elliptically shaped out of focus objects produced by fixed focal length (commonly referred to as prime) anamorphic objective lenses. The oval or elliptically shaped bokeh of out of focus objects are desired by cinematographers because they produce a distinctive artistic look that is different from spherical objective lenses. Another common drawback with this anamorphic objective zoom lens arrangement is that the full aperture may be relatively slow as compared to that of anamorphic prime lenses. 
     Anamorphic objective zoom lenses having a front anamorphic lens group have a front lens group with X cylinder refractive optical surfaces and a rear spherical lens group with an optical stop in the rear spherical lens group in the form of a variable aperture diameter iris or diaphragm. 
     This anamorphic objective zoom lens arrangement produces images having oval or elliptically shaped out of focus objects commonly referred to as the bokeh which is desired by cinematographers for the reasons previously given however these lenses normally provide only small zoom ratios of 2× or 3×, where the smaller zoom ratio provides the widest field of view, and they tend be large in diameter with corresponding potentially higher weight and cost. They may also exhibit some breathing when focusing where the breathing is characterized by the field of view or focal length of the lens changing size as the lens is focused from distant to close objects or vice versa. In addition they may also produce a thermally induced focus shift with change of temperature where the focus shift is not constant over wide to narrow fields of view and the image is characterized by having residual astigmatism. Nevertheless the front anamorphic objective zoom lens arrangements produce images having numerous residual optical aberrations and characteristics most of which are desired by cinematographers because they produce an artistic look that is different from spherical objective lenses. 
     Many of the less desired residual optical aberrations and characteristics of these front and rear anamorphic objective zoom lens arrangements were accepted by cinematographers with film based cameras but with the advent and adoption of electronic sensor based digital cameras some of them have become less acceptable. In particular the amount of residual chromatic aberration has become less tolerable whereas some field curvature combined with some residual astigmatism is still acceptable. 
     As well as the oval or elliptically shaped bokeh another characteristic that is desired because of the distinctive artistic look produced is the depth of field being different in the vertical azimuth direction of the field versus the horizontal azimuth direction of the field. In the case of an anamorphic objective zoom lens that squeezes the horizontal field of view by substantially two times as compared to the vertical field of view, the depth of field in the horizontal azimuth direction of the field is substantially two times greater than the depth of field in the vertical azimuth direction of the field. 
     Improving the optical aberrations and characteristics of anamorphic objective zoom lenses of this arrangement may involve increasing optical surface shape complexity and hence manufacturing cost including adding aspherical and free-form shaped optical surfaces. 
     Thus, to address the artistic need of cinematographers and maximize the imaging potential of both film and digital cameras a compact diameter anamorphic objective zoom lens arrangement that provides a useful zoom range going from wide to narrow fields of view during zooming with a suitable blend of residual optical aberration correction and characteristics needs to be achieved. 
     Lenses of this type tend to be sensitive to changes in temperature and will go out of focus without some means of compensating for temperature shifts. Accordingly, there is a need for including some means of providing thermal compensation to maintain the focus over the temperature range in which the lens will operate. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention relates to an anamorphic objective zoom lens including, along an optical axis and in order from an object space to an image space, at least a negative (−) power spherical first lens group: an anamorphic second lens group, a spherical third lens group preferably having a positive (+) power, a variable power spherical zoom fourth lens group and a positive (+) power spherical fifth lens group wherein an aperture stop is located before, after or preferably within the spherical fifth power lens group. The anamorphic second lens group has at least one cylindrical surface in a first direction and at least one other cylindrical surface in a substantially perpendicular direction to the first direction to enable a high degree of aberration correction over the whole image, whereby the residual longitudinal chromatic aberration and the residual lateral chromatic aberration are substantially reduced. The variable power spherical fourth lens group has at least two lens sub groups that are axially movable to provide zooming. The negative power spherical first lens group may provide focusing by movement of at least one of the lens elements contained therein and may exhibit low breathing in the focus range. Lens elements of the spherical third and fifth lens groups are independently axially movable by active or passive or active and passive means while preferably maintaining the overall length of the anamorphic objective zoom lens to provide thermal compensation of defocus which is consistently small and has little astigmatism through focusing and zooming. The lens is a complete assembly that forms a real image. 
     The anamorphic second lens group provides a squeeze of the field of view so that the focal lengths in the X and Y directions are different by a ratio of about two times which is typical for traditional anamorphic optical systems. The positive power spherical fifth lens group adjacent the image space delivers the radiation passing through the optical system on to the image sensor with nearly telecentric light paths and suitably high relative illumination, thereby increasing the efficiency of many electronic sensors. 
     The variable power spherical zoom fourth lens group which provides zooming uses at least two axially movable lens sub groups. The variable power spherical zoom fourth lens group is located between object space and the optical stop thus providing a substantially near constant aperture through zoom. 
     The lens elements of the spherical third and fifth lens groups which provide thermal compensation of defocus through focusing and zooming can be independently axially moved by active means employing motors or passive means utilizing materials exhibiting suitable thermal expansion coefficients in the mechanical support of the lens elements or a combination of both means. The thermal compensation of defocus by active, passive or combined means has the additional advantage of not requiring the operator of the lens to refocus the lens and the associated loss of focus scale calibration. The thermal compensation of defocus by passive means has the additional advantage of not requiring the complexity of a power source for motors. 
     In accordance with one aspect of the present invention, an anamorphic objective zoom lens is provided including, along an optical axis and in order from an object space to an image space, a negative (−) power spherical first lens group; an anamorphic second lens group, a spherical third lens group preferably having a positive (+) power, a variable power spherical zoom fourth lens group and a positive (+) power spherical fifth lens group and an aperture stop. The aperture stop is located in a position either before, after and within the spherical fifth lens group. At least one lens element of said spherical third lens group and at least one lens element of said spherical fifth lens group are independently axially adjustable to compensate for thermal defocus in image space for at least two focal lengths within the focal length range. 
     Preferably, the lens elements of the spherical third lens group are moveable together, the lens elements of the spherical fifth lens group are moveable together, and the spherical third lens group and the spherical fifth lens group are independently axially adjustable to compensate for thermal defocus in image space for at least two focal lengths within the focal length range. 
     Preferably, the aperture stop is located within the positive (+) power spherical fifth lens group. 
     The negative (−) power spherical first lens group is configured to provide focusing. 
     The anamorphic objective zoom lens has an optical axis. The first, second, third, fourth and fifth lens groups are situated along the optical axis. The anamorphic objective zoom lens is adapted for use between an object space and an image space. The optical axis extends between the object space and the image space. 
     The fifth lens group has at least one cylindrical surface in a first direction and at least one cylindrical surface in a direction substantially perpendicular to the first direction. 
     The fifth lens group has focal lengths in the X and Y directions which differ and together with the other lens group focal lengths produce focal lengths in X and Y directions which differ by a ratio of about two times. 
     The anamorphic objective zoom lens preferably has a focal length within the range of from at least 35 mm to 140 mm and preferably 40 mm to 125 mm in the Y direction. 
     The anamorphic objective zoom lens provides low residual chromatic aberration, a traditional oval bokeh shape, and different depths of field in the vertical and horizontal azimuth directions of the field. 
     The anamorphic objective zoom lens has a medium fast full aperture, moderately wide angle field of view to a moderately narrow angle field of view throughout its zoom lens range. 
     The lens groups of the anamorphic objective zoom lens are fabricated of lens elements made of glass. 
     The spherical lens groups include a lens element with a rotationally symmetrical surface shape about the optical axis. 
     The lens group with anamorphic powers includes a lens element with a non-rotationally symmetrical surface about the optical axis. 
     The anamorphic objective zoom lens preferably operates at an aperture of f/3.1 and over a waveband of 455-656 nm. 
     The anamorphic second lens group has seven cylindrically surfaced lens elements with eight Y cylinders, five X cylinders and one plano surface shapes. 
     The spherical first lens group includes five lens elements, three of which are axially moveable relative to the other. 
     The spherical third lens group includes four lens elements. 
     The spherical zoom fourth lens group includes five lens elements, three of which form a first zoom sub group and two of which form a second zoom sub group, both of which are axially movable. 
     The spherical fifth lens group includes nine lens elements. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF DRAWINGS 
       To these and to such other objects that may hereinafter appear, the present invention relates to an anamorphic objective zoom lens as described in detail in the following specification and recited in the annexed claims, taken together with the accompanying drawings, in which like numerals refer to like parts and in which: 
         FIG. 1  is a lens plot in the YZ elevation (side view) and XZ elevation (plan view) on an optical axis Ø where the Y direction focal length is 51.00 mm and the X direction focal length is 26.21 mm. In the YZ elevation, three fields are shown at zero, top and bottom of the field of view. In the XZ elevation, three fields are shown at zero and both sides of the field of view. In the YZ elevation and in the XZ elevation diagrams an intermediate focus distance arrangement is shown; 
         FIG. 2  is a lens plot in the YZ elevation (side view) on an optical axis Ø where the Y direction focal lengths are 40.01 mm, 67.98 mm and 125.01 mm with three fields shown at zero, top and bottom of the field of view and the top to bottom diagrams showing far, intermediate and close focus distance arrangements; and 
         FIG. 3  is a lens plot in the XZ elevation (plan view) on an optical axis Ø where the X direction focal length are 20.57 mm, 34.94 mm and 64.27 mm with three fields shown at zero and both sides of the field of view and the top to bottom diagrams showing far, intermediate and close focus distance arrangements. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention relates to anamorphic objective zoom lenses, and in particular to a range of different focal length anamorphic objective zoom lenses covering at least a focal length range from 35 mm to 140 mm and preferably 40 mm to 125 mm in the Y direction and providing low residual chromatic aberration, a traditional oval bokeh shape and different depths of field in the vertical and horizontal azimuth directions of the field. 
     The term “lens group” as used in connection with the anamorphic objective zoom lens disclosed herein means one or more individual lens elements. Also, the terms “optical stop” and “stop” are equivalent terms that can be used interchangeably. 
     The example provided herein is a preferred embodiment of the invention in which the first (front) lens group is negatively powered, the third lens group is positively powered, the fourth lens group is variable powered and the last (rear) lens group is positively powered. Those lens groups are paired with an anamorphic second lens group to work in unison and match the preferred optical interface characteristics of sensors, where near telecentric radiation beams approach the sensor. 
     The preferred embodiment discussed below is a medium fast full aperture moderately wide angle field of view to moderately narrow angle field of view anamorphic objective lens of the zoom. 
     In the preferred embodiment, all of the lens elements are made from glasses. The lens element optical surface shapes in the first, third, fourth and fifth spherical lens groups are all rotationally symmetrical about the optical axis such as spherical and in the anamorphic second lens group at least one lens element surface shape is non-rotationally symmetrical about the optical axis such as cylindrical. 
     In addition to providing these kinds of features and others like low breathing and (near) telecentric radiation output at the sensor, the preferred embodiment is capable of achieving suitable levels of various performance including image quality resolution and contrast (usually measured as MTF), high relative illumination for low shading and efficient optical throughput at the sensor via near telecentric radiation output at the sensor, which telecentric radiation output is less than 10 degrees. 
     The preferred embodiment of the present invention will now be described by way of a design example with accompanying figures and tables. Referring first to  FIG. 1 , each lens element is identified by a numeral from  1  through  30  and the general configuration of each lens element is depicted, but the actual radius of each lens surface is set forth below in a table. The lens surfaces are identified by the letter “S” followed by a numeral from S 1  through S 58 . 
     Each lens element has its opposite surfaces identified by a separate but consecutive surface number as, for example, lens element  1  has lens surfaces S 2  and S 3 , lens element  11  has lens surfaces S 21  and S 22  and so forth, as shown in  FIG. 1 , except that for doublet lens element pairs  3 ,  4  and  14 ,  15  and  18 ,  19  and  23 ,  24  the coincident facing lens surfaces are given a single surface number. For example, doublet lens element pair  3 ,  4  is comprised of lens element  3  having a front lens surface S 6  and a rear lens surface S 7  and lens element  4  having a front lens surface S 7  (coincidental) and a rear lens surface S 8 . The location of the object to be photographed, particularly as it relates to focus distance, is identified by a vertical line and numeral “S 1 ” on the optical axis, and the real image surface is identified by the numeral S 59 . All of the spherical lens surfaces have a finite radius of curvature except S 10  which is piano and all the cylindrically surfaced lens elements have a finite radius of curvature in X or Y directions except for S 14  which is piano. 
     Before describing the detailed characteristics of the lens elements, a broad description of the lens groups and their axial positions and movement will be given for the anamorphic objective zoom lens system of the present invention, generally designated  50 . Beginning from the end facing the object S 1  to be photographed. i.e. the left end in  FIG. 1 , the spherical first lens group G 1  comprises lens elements  1  and  2  and a lens sub group SG 11  comprised of lens elements  3 ,  4  and  5 . The anamorphic second lens group G 2  comprises lens elements  6 ,  7 ,  8 ,  9 ,  10 ,  11  and  12 . The spherical third lens group G 3  includes lens elements  13 ,  14 ,  15  and  16 . The variable power spherical zoom fourth lens group G 4  includes, from left to right in  FIG. 1 , lens sub group SG 41  including lens elements  17 ,  18 , and  19 , and lens sub group SG 42  including lens elements  20  and  21 . The spherical fifth lens group G 5  closest to the image space includes lens elements  22 ,  23 ,  24 ,  25 ,  26 ,  27 ,  28 ,  29  and  30 . 
     The images of  FIG. 2  illustrate in the Y direction the movement of lens sub group G 11  in both directions along the optical axis for focusing at three focus positions and the movement of lens sub groups SG 41  and SG 42  in both directions along the optical axis for zooming at three positions. 
     The images of  FIG. 3  illustrate in the X direction the movement of lens sub group G 11  in both directions along the optical axis for focusing at three focus positions and the movement of lens sub groups SG 41  and SG 42  in both directions along the optical axis for zooming at three positions. 
     In  FIGS. 2 and 3  the auxiliary lens fifth group G 5  remains stationary and at a fixed distance from the real image surface S 59 . 
     While only the lens elements are physically shown in  FIG. 1 , it is to be understood that conventional mechanical devices and mechanisms are provided for supporting the lens elements and for causing axial movement of the movable lens groups in a conventional lens housing or barrel. 
     The Optical Prescription data for the above described anamorphic zoom lens system  50  is set forth below in TABLE 1, which is extracted from data produced by CODE V® optical design software that is commercially available from Synopsis Optical Research Associates, Inc. Pasadena, Calif., U.S.A., which was also used for producing the optical diagrams. All of the data in TABLE 1 is given at a temperature of 25° C. (77° F.) and standard atmospheric pressure (760 mm Hg). 
     Throughout this specification, including the Tables, all measurements are in millimeters (mm) or as otherwise shown. In TABLE 1, the first column “ITEM” identifies each optical element and each location, i.e. object plane, etc., with the same numeral or label as used in  FIG. 1 . The second and third columns identify the “Group” and “Subgroup”, respectively, to which that optical element (lens) belongs with the same numerals used in  FIG. 1 . The fourth column “Surface” is a list of the surface numbers and the fifth column “Shape” is the surface shape. 
     The sixth and seventh columns “Focus Position” and “Zoom Position”, respectively, identify the typical focus positions of the spherical lens group and the typical positions of the lens elements in the variable power spherical zoom fourth lens group wherein there are changes in the distance (separation) between some of the surfaces listed in the “Separation” column which is the axial distance between that surface (fourth column) and the next surface, for example, the distance between surface S 2  to surface S 3  is 5.579 mm. 
     The columns headed by the legends “Y Radius of Curvature” and “X Radius of Curvature” list the optical surface radius of curvature for each surface in the Y and X plane, respectively, with a minus sign (−) meaning the center of the radius of curvature is to the left of the surface, as viewed in  FIG. 1 , and “Flat” meaning an optically flat surface described as “Plano” in column  5 . 
     The next four columns,  11  to  14 , of TABLE 1 relate to the “Material” between that surface and the next surface to the right in  FIG. 1 , with the eleventh column “Type” indicating whether there is a lens (Glass) or empty space (Air) between those two surfaces. All of the lenses are glass and the column titled “Code” identifies the optical glass. The column marked “Supplier” identifies the source of the lens and the column marked “Name” lists the Supplier&#39;s identification for each glass type, but it is to be understood that any equivalent or adequate glass may be used. 
     The last column of TABLE 1 headed “Aperture Half Diameter” provides the maximum aperture half diameter for each surface through which the light rays pass. 
     The novel configuration of having a negatively powered spherical first lens group, an anamorphic second lens group followed by a spherical third lens group preferably with a positive power, a variable power spherical fourth lens group and a positively powered spherical fifth lens group containing an optical stop may produce some residual distortion, astigmatism and field curvature aberrations but those aberrations to a tolerable extent contribute to the anamorphic look as desired by many cinematographers. In addition, a balanced blend of the afore-described lens characteristics may aid in cost reduction of manufacture. With the advent and adoption of digital cameras employing electronic sensors a large back focal length which was once required for film cameras having a reflex mirror may be less necessary but is still provided for in the novel anamorphic objective zoom lens. 
     The preferred embodiment operates at an aperture of f/3.1 and over a waveband of 455-656 nm and this waveband is what was used in the MTF Table 3. A faster or slower aperture may be required and an extended waveband may be required. The aperture may be increased or reduced and the waveband expanded and the optical designs re-optimized to maximize image quality over such apertures and wavebands without departing from the invention. Also, during such re-optimization alternate glass types may be used without departing from the spirit and scope of the disclosure. Furthermore, more complex optical surface shapes such as aspherical and free-form surfaces may be introduced for expanded performance but at the likely effect of increased manufacturing cost. 
     Referring to  FIGS. 1-3 , those figures relate to the preferred embodiment in which the focal length in the Y directions are 40.01 mm, 67.98 mm and 125.01 mm and in the X directions are 20.57 mm, 34.94 mm and 64.27 mm. The overall length is 477 mm from the first refractive surface vertex of the lens to the image surface vertex, the front diameter clear aperture is 114.00 mm, the back focal length from the rear refractive surface vertex to the image vertex is 37.17 mm and the close focus distance from the object to the image is 1165 mm. The focal lengths of the spherical first lens group are −116.86 mm, −118.72 mm and −120.67 mm for the far, intermediate and close focus distances. The focal lengths of the anamorphic second lens group are +306.23 mm in the Y direction and −284.96 mm in the X direction. The focal length of the spherical third lens group is 107.33 mm. The focal lengths of the spherical fourth lens group with zooming are −90.88 mm, −100.10 mm and −70.74 mm for the short, medium and long focal length positions. The focal length of the spherical fifth lens group is 86.52 mm. The focal lengths of the focusing sub group and the zooming sub groups respectively are −265.40 mm, −46.15 mm and 190.83 mm. 
       FIGS. 2 and 3  show the locus of axial movement of the focusing sub group with a long dashed curve and the locus of axial movements of the zooming sub groups with short dashed curves where the closest approach of the zooming sub group nearest image space to the adjacent stationary lens element lies between zoom positions three (Z 3 ) and five (Z 5 ), of which the axial airspace distance of closest approach is given approximately by the data for zoom position Z 4  in Table 1 which accompanies this specification. 
     The focal lengths of the seven anamorphic lens elements containing at least one cylindrical surface are in order from an object space to an image space −75.75 mm (in X direction), −150.63 mm (in X direction), −561.89 mm (in Y direction), 87.29 mm (in X direction), 141.59 mm (in Y direction), −3906.70 mm (in Y direction) and −230.05 mm (in Y direction). It is to be understood that the focal lengths of the seven anamorphic lens elements in the other X and Y directions are substantially large and hence have little optical power. 
     In the preferred embodiment the lens system includes a total of thirty lens elements with twenty two singlets and four doublets. The spherical first lens group contains five lens elements with three elements axially movable for focusing at different distances, the anamorphic second lens group contains seven cylindrically surfaced lens elements with eight Y cylinders, five X cylinders and one plano surface shape, the spherical second group contains four lens elements, the zoom fourth lens group contains five lens elements which form two axially movable sub groups for zooming with three lens elements and two lens elements. The optical stop lies within the spherical fifth lens group. The nominal image size is 8.91 mm vertical half height and 10.65 mm horizontal half width in image space. In this example embodiment the telecentric radiation output is about 9.1 degrees at all three focus positions and over the zoom range. 
     The accompanying Optical Prescription Table 1 describes a select example of the preferred embodiment of the anamorphic objective zoom lens disclosed herein. 
     Table 2 which accompanies this specification contains focal length, anamorphic squeeze, illumination and breathing data of the preferred embodiment. In Table 2 it is shown that the anamorphic squeeze ratio is within a small range of about 1.95% to 2.03%. In Table 2 it is also shown that the relative illumination is above 30%, which is sufficiently high for low shading at the corner of the field of view when an anamorphic objective zoom lens is used in combination with an electronic sensor at the image plane, such as when the anamorphic objective zoom lens constitutes part of a digital camera. In Table 2 it is further shown that the focus breathing is consistently very small through focusing and zooming. 
     In Table 3 which accompanies the specification, the polychromatic MTF performance at a spatial frequency of 20 cycles/mm is shown for the example embodiment to be greater than 50% at all field positions at the given combination of far, intermediate and close focus distances and short, medium and long focal lengths at a temperature of 25° C. (77° F.) and standard atmospheric pressure (760 mm Hg). 
     In Table 4 which accompanies the specification, the polychromatic MTF performance at a spatial frequency of 20 cycles/mm is shown for the example embodiment to be greater than 50% at all field positions at the given combination of far, intermediate and close focus distances and short, medium and long focal lengths at a temperature of 40° C. (104° F.) and standard atmospheric pressure (760 mm Hg). The third and fifth lens groups are axially moved to compensate for thermal defocus. The movements are given by respectively changing the separations of surfaces S 24 , S 31 , S 50  and S 58  by −0.126 mm, +0.126 mm, +0.054 mm and −0.054 mm. 
     In Table 5 which accompanies the specification, the polychromatic MTF performance at a spatial frequency of 20 cycles/mm is shown for the example embodiment to be greater than 50% at all field positions at the given combination of far, intermediate and close focus distances and short, medium and long focal lengths at a temperature of 10° C. (50° F.) and standard atmospheric pressure (760 mm Hg). The third and fifth lens groups are axially moved to compensate for thermal defocus. The movements are given by respectively changing the separations of surfaces S 24 , S 31 , S 50  and S 58  by mm, +0.126 mm, −0.126 mm, −0.054 mm and +0.054 mm. 
     In Tables 4 and 5 the polychromatic MTF of the anamorphic objective zoom lens system  50  has been computed theoretically in accordance with accepted optical principles and programs such as CODE V® optical design software. The glass coefficients of refractive index and expansion with temperature were obtained from commonly available data publications produced by the vendor corporations Ohara and Schott. All optical surface separations between lens elements are thermally controlled by the expansion and contraction of metal spacers made of aluminum contacting the optical surfaces at their clear apertures which are two times the aperture half diameter values given in Table 1. The temperature range of the anamorphic objective zoom lens system  50 , as designed and as described herein, is 10° C. (50° F.) to 40° C. (104° F.) with a nominal design temperature of 25° C. (77° F.). However, this anamorphic objective zoom lens system will maintain a high level of performance over at least an extended range of −10° C. to 50° C., although some degradation of image quality may be observed at low temperatures. 
     The seven anamorphic lens elements with the cylindrical surfaces of the example embodiment additionally may each have two refractive surfaces which may be formed by X and Y cylindrical surfaces or Y and X cylindrical surfaces with the X and Y surfaces substantially perpendicular to one another. This arrangement may improve the imaging characteristics but likely at the effect of additional manufacturing cost. 
     Although the present invention has been fully described in connection with a preferred embodiment thereof with reference to the accompanying drawings and data tables, various changes and modifications could be made thereto, including smaller and larger zoom ranges, smaller and larger focal lengths, smaller and larger anamorphic squeeze ratios, smaller and larger full aperture f/numbers, smaller and larger image sizes, smaller and larger wavebands, etc. (e.g., 435 nm to 656 nm), as will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the present invention as defined by the appended claims. 
     
       
         
           
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Optical Prescription 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                 Y Radius of 
                 X Radius of 
               
               
                   
                 Sub- 
                 Surface 
                 Focus 
                 Zoom 
                 Separation 
                 Curvature 
                 Curvature 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 Item 
                 Group 
                 Group 
                 No. 
                 Shape 1   
                 Position 
                 Position 2,3   
                 (mm) 
                 (mm) 
                 (mm) 
               
               
                   
               
               
                 Object 
                   
                   
                 S1 
                 Plano 
                 F1 
                 All 
                 999999.000 
                 Flat 
                 Flat 
               
               
                 Plane 
                   
                   
                   
                   
                 F2 
                 All 
                 1965.000 
                   
                   
               
               
                   
                   
                   
                   
                   
                 F3 
                 All 
                 943.000 
                   
                   
               
               
                 1 
                 G1 
                   
                 S2 
                 Sph. 
                 All 
                 All 
                 5.579 
                 364.892 
                 364.892 
               
               
                   
                   
                   
                 S3 
                 Sph. 
                 All 
                 All 
                 0.450 
                 84.772 
                 84.772 
               
               
                 2 
                 G1 
                   
                 S4 
                 Sph. 
                 All 
                 All 
                 11.657 
                 79.239 
                 79.239 
               
               
                   
                   
                   
                 S5 
                 Sph. 
                 F1 
                 All 
                 39.560 
                 105.024 
                 105.024 
               
               
                   
                   
                   
                   
                   
                 F2 
                 All 
                 30.907 
                   
                   
               
               
                   
                   
                   
                   
                   
                 F3 
                 All 
                 22.175 
                   
                   
               
               
                 3 
                 G1 
                 SG11 
                 S6 
                 Sph. 
                 All 
                 All 
                 6.899 
                 −585.944 
                 −585.944 
               
               
                 4 
                 G1 
                 SG11 
                 S7 
                 Sph. 
                 All 
                 All 
                 4.873 
                 −303.627 
                 −303.627 
               
               
                   
                   
                   
                 S8 
                 Sph. 
                 All 
                 All 
                 5.832 
                 495.133 
                 495.133 
               
               
                 5 
                 G1 
                 SG11 
                 S9 
                 Sph. 
                 All 
                 All 
                 4.517 
                 −261.296 
                 −261.296 
               
               
                   
                   
                   
                 S10 
                 Plano 
                 F1 
                 All 
                 11.045 
                 Flat 
                 Flat 
               
               
                   
                   
                   
                   
                   
                 F2 
                 All 
                 19.697 
                   
                   
               
               
                   
                   
                   
                   
                   
                 F3 
                 All 
                 28.430 
                   
                   
               
               
                 6 
                 G2 
                   
                 S11 
                 X Cyl. 
                 All 
                 All 
                 4.337 
                 Flat 
                 −82.662 
               
               
                   
                   
                   
                 S12 
                 X Cyl. 
                 All 
                 All 
                 9.184 
                 Flat 
                 70.673 
               
               
                 7 
                 G2 
                   
                 S13 
                 X Cyl. 
                 All 
                 All 
                 4.249 
                 Flat 
                 −75.084 
               
               
                   
                   
                   
                 S14 
                 Plano 
                 All 
                 All 
                 1.385 
                 Flat 
                 Flat 
               
               
                 8 
                 G2 
                   
                 S15 
                 Y Cyl. 
                 All 
                 All 
                 4.959 
                 −908.544 
                 Flat 
               
               
                   
                   
                   
                 S16 
                 Y Cyl. 
                 All 
                 All 
                 4.334 
                 920.220 
                 Flat 
               
               
                 9 
                 G2 
                   
                 S17 
                 X Cyl. 
                 All 
                 All 
                 14.948 
                 Flat 
                 263.078 
               
               
                   
                   
                   
                 S18 
                 X Cyl. 
                 All 
                 All 
                 4.367 
                 Flat 
                 −88.994 
               
               
                 10 
                 G2 
                   
                 S19 
                 Y Cyl. 
                 All 
                 All 
                 11.981 
                 246.798 
                 Flat 
               
               
                   
                   
                   
                 S20 
                 Y Cyl. 
                 All 
                 All 
                 7.962 
                 −161.076 
                 Flat 
               
               
                 11 
                 G2 
                   
                 S21 
                 Y Cyl. 
                 All 
                 All 
                 27.028 
                 69.953 
                 Flat 
               
               
                   
                   
                   
                 S22 
                 Y Cyl. 
                 All 
                 All 
                 15.808 
                 58.918 
                 Flat 
               
               
                 12 
                 G2 
                   
                 S23 
                 Y Cyl. 
                 All 
                 All 
                 3.800 
                 −76.352 
                 Flat 
               
               
                   
                   
                   
                 S24 
                 Y Cyl. 
                 All 
                 All 
                 3.889 
                 −232.274 
                 Flat 
               
               
                 13 
                 G3 
                   
                 S25 
                 Sph. 
                 All 
                 All 
                 10.900 
                 137.891 
                 137.891 
               
               
                   
                   
                   
                 S26 
                 Sph. 
                 All 
                 All 
                 0.519 
                 −214.419 
                 −214.419 
               
               
                 14 
                 G3 
                   
                 S27 
                 Sph. 
                 All 
                 All 
                 3.550 
                 259.088 
                 259.088 
               
               
                 15 
                 G3 
                   
                 S28 
                 Sph. 
                 All 
                 All 
                 14.662 
                 64.133 
                 64.133 
               
               
                   
                   
                   
                 S29 
                 Sph. 
                 All 
                 All 
                 0.500 
                 −353.262 
                 −353.262 
               
               
                 16 
                 G3 
                   
                 S30 
                 Sph. 
                 All 
                 All 
                 8.144 
                 97.834 
                 97.834 
               
               
                   
                   
                   
                 S31 
                 Sph. 
                 All 
                 Z1 
                 7.030 
                 635.356 
                 635.356 
               
               
                   
                   
                   
                   
                   
                 All 
                 Z2 
                 26.780 
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                 Z3 
                 46.204 
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                 Z4 
                 64.237 
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                 Z5 
                 75.329 
                   
                   
               
               
                 17 
                 G4 
                 SG41 
                 S32 
                 Sph. 
                 All 
                 All 
                 2.200 
                 −159.777 
                 −159.777 
               
               
                   
                   
                   
                 S33 
                 Sph. 
                 All 
                 All 
                 5.133 
                 58.576 
                 58.576 
               
               
                 18 
                 G4 
                 SG41 
                 S34 
                 Sph. 
                 All 
                 All 
                 2.200 
                 −77.157 
                 −77.157 
               
               
                 19 
                 G4 
                 SG41 
                 S35 
                 Sph. 
                 All 
                 All 
                 5.066 
                 53.293 
                 53.293 
               
               
                   
                   
                   
                 S36 
                 Sph. 
                 All 
                 Z1 
                 43.249 
                 880.564 
                 880.564 
               
               
                   
                   
                   
                   
                   
                 All 
                 Z2 
                 40.464 
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                 Z3 
                 34.324 
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                 Z4 
                 21.994 
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                 Z5 
                 6.735 
                   
                   
               
               
                 20 
                 G4 
                 SG42 
                 S37 
                 Sph. 
                 All 
                 All 
                 2.800 
                 180.566 
                 180.566 
               
               
                   
                   
                   
                 S38 
                 Sph. 
                 All 
                 All 
                 1.047 
                 109.323 
                 109.323 
               
               
                 21 
                 G4 
                 SG42 
                 S39 
                 Sph. 
                 All 
                 All 
                 5.665 
                 126.917 
                 126.917 
               
               
                   
                   
                   
                 S40 
                 Sph. 
                 All 
                 Z1 
                 38.886 
                 −118.086 
                 −118.086 
               
               
                   
                   
                   
                   
                   
                 All 
                 Z2 
                 21.921 
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                 Z3 
                 8.637 
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                 Z4 
                 2.935 
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                 Z5 
                 7.102 
                   
                   
               
               
                 22 
                 G5 
                   
                 S41 
                 Sph. 
                 All 
                 All 
                 6.264 
                 119.224 
                 119.224 
               
               
                   
                   
                   
                 S42 
                 Sph. 
                 All 
                 All 
                 0.500 
                 −142.072 
                 −142.072 
               
               
                 23 
                 G5 
                   
                 S43 
                 Sph. 
                 All 
                 All 
                 7.260 
                 81.255 
                 81.255 
               
               
                 24 
                 G5 
                   
                 S44 
                 Sph. 
                 All 
                 All 
                 2.600 
                 −93.115 
                 −93.115 
               
               
                   
                   
                   
                 S45 
                 Sph. 
                 All 
                 All 
                 0.500 
                 156.198 
                 156.198 
               
               
                 25 
                 G5 
                   
                 S46 
                 Sph. 
                 All 
                 All 
                 5.501 
                 44.318 
                 44.318 
               
               
                   
                   
                   
                 S47 
                 Sph. 
                 All 
                 All 
                 0.500 
                 160.913 
                 160.913 
               
               
                 26 
                 G5 
                   
                 S48 
                 Sph. 
                 All 
                 All 
                 3.694 
                 42.727 
                 42.727 
               
               
                   
                   
                   
                 S49 
                 Sph. 
                 All 
                 All 
                 7.499 
                 61.123 
                 61.123 
               
               
                 Stop 
                   
                   
                 S50 
                 Plano 
                 All 
                 All 
                 11.321 
                 Flat 
                 Flat 
               
               
                 27 
                 G5 
                   
                 S51 
                 Sph. 
                 All 
                 All 
                 2.000 
                 112.584 
                 112.584 
               
               
                   
                   
                   
                 S52 
                 Sph. 
                 All 
                 All 
                 3.094 
                 26.037 
                 26.037 
               
               
                 28 
                 G5 
                   
                 S53 
                 Sph. 
                 All 
                 All 
                 2.137 
                 108.389 
                 108.389 
               
               
                   
                   
                   
                 S54 
                 Sph. 
                 All 
                 All 
                 3.023 
                 30.081 
                 30.081 
               
               
                 29 
                 G5 
                   
                 S55 
                 Sph. 
                 All 
                 All 
                 3.457 
                 168.931 
                 168.931 
               
               
                   
                   
                   
                 S56 
                 Sph. 
                 All 
                 All 
                 16.389 
                 −63.194 
                 −63.194 
               
               
                 30 
                 G5 
                   
                 S57 
                 Sph. 
                 All 
                 All 
                 3.904 
                 34.718 
                 34.718 
               
               
                   
                   
                   
                 S58 
                 Sph. 
                 All 
                 All 
                 37.175 
                 44.308 
                 44.308 
               
               
                 Image 
                   
                   
                 S59 
                 Y &amp; X Cy 
                 F1 
                 Z1 
                 463.940 
                 1029.861 
                   
               
               
                 Surface 
                   
                   
                   
                 Y &amp; X Cy 
                 F2 
                 Z1 
                 390.380 
                 −2461.934 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F3 
                 Z1 
                 337.004 
                 −589.389 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F1 
                 Z2 
                 350.000 
                 728.306 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F2 
                 Z2 
                 315.862 
                 −22158.909 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F3 
                 Z2 
                 300.000 
                 −1266.833 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F1 
                 Z3 
                 331.907 
                 984.085 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F2 
                 Z3 
                 320.000 
                 Flat 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F3 
                 Z3 
                 300.000 
                 −2186.394 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F1 
                 Z4 
                 437.714 
                 −6078.194 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F2 
                 Z4 
                 388.741 
                 −903.184 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F3 
                 Z4 
                 294.968 
                 −696.366 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F1 
                 Z5 
                 816.007 
                 −2031.177 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F2 
                 Z5 
                 Flat 
                 Flat 
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F3 
                 Z5 
                 550.000 
                 −1039.893 
                   
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                 Aperture 6   
               
               
                   
                   
                   
                   
                   
                 Half 
               
               
                   
                 Sub- 
                 Surface 
                 Focus 
                 Material 
                 Diameter 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Item 
                 Group 
                 Group 
                 No. 
                 Shape 1   
                 Position 
                 Type 
                 Code 
                 Name 4   
                 Supplier 5   
                 (mm) 
               
               
                   
               
               
                 Object 
                   
                   
                 S1 
                 Plano 
                 F1 
                 Air 
                   
                   
                   
                   
               
               
                 Plane 
                   
                   
                   
                   
                 F2 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 F3 
                   
                   
                   
                   
                   
               
               
                 1 
                 G1 
                   
                 S2 
                 Sph. 
                 All 
                 Glass 
                 755523 
                 SYGH51 
                 OHARA 
                 57.00 
               
               
                   
                   
                   
                 S3 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 50.11 
               
               
                 2 
                 G1 
                   
                 S4 
                 Sph. 
                 All 
                 Glass 
                 805254 
                 SF6 
                 SCHOTT 
                 49.83 
               
               
                   
                   
                   
                 S5 
                 Sph. 
                 F1 
                 Air 
                   
                   
                   
                 47.52 
               
               
                   
                   
                   
                   
                   
                 F2 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 F3 
                   
                   
                   
                   
                   
               
               
                 3 
                 G1 
                 SG11 
                 S6 
                 Sph. 
                 All 
                 Glass 
                 805254 
                 SF6 
                 SCHOTT 
                 42.75 
               
               
                 4 
                 G1 
                 SG11 
                 S7 
                 Sph. 
                 All 
                 Glass 
                 497816 
                 SFPL51 
                 OHARA 
                 41.81 
               
               
                   
                   
                   
                 S8 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 39.59 
               
               
                 5 
                 G1 
                 SG11 
                 S9 
                 Sph. 
                 All 
                 Glass 
                 618634 
                 SPHM52 
                 OHARA 
                 39.18 
               
               
                   
                   
                   
                 S10 
                 Plano 
                 F1 
                 Air 
                   
                   
                   
                 38.28 
               
               
                   
                   
                   
                   
                   
                 F2 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 F3 
                   
                   
                   
                   
                   
               
               
                 6 
                 G2 
                   
                 S11 
                 X Cyl. 
                 All 
                 Glass 
                 497816 
                 SFPL51 
                 OHARA 
                 32.83 
               
               
                   
                   
                   
                 S12 
                 X Cyl. 
                 All 
                 Air 
                   
                   
                   
                 32.43 
               
               
                 7 
                 G2 
                   
                 S13 
                 X Cyl. 
                 All 
                 Glass 
                 497816 
                 SFPL51 
                 OHARA 
                 32.42 
               
               
                   
                   
                   
                 S14 
                 Plano 
                 All 
                 Air 
                   
                   
                   
                 32.65 
               
               
                 8 
                 G2 
                   
                 S15 
                 Y Cyl. 
                 All 
                 Glass 
                 805254 
                 SF6 
                 SCHOTT 
                 32.70 
               
               
                   
                   
                   
                 S16 
                 Y Cyl. 
                 All 
                 Air 
                   
                   
                   
                 32.95 
               
               
                 9 
                 G2 
                   
                 S17 
                 X Cyl. 
                 All 
                 Glass 
                 773.5 
                 SLAH66 
                 OHARA 
                 33.41 
               
               
                   
                   
                   
                 S18 
                 X Cyl. 
                 All 
                 Air 
                   
                   
                   
                 33.90 
               
               
                 10 
                 G2 
                   
                 S19 
                 Y Cyl. 
                 All 
                 Glass 
                 694.51 
                 SLAL58 
                 OHARA 
                 35.18 
               
               
                   
                   
                   
                 S20 
                 Y Cyl. 
                 All 
                 Air 
                   
                   
                   
                 35.45 
               
               
                 11 
                 G2 
                   
                 S21 
                 Y Cyl. 
                 All 
                 Glass 
                 487702 
                 SFSL5 
                 OHARA 
                 34.72 
               
               
                   
                   
                   
                 S22 
                 Y Cyl. 
                 All 
                 Air 
                   
                   
                   
                 30.15 
               
               
                 12 
                 G2 
                   
                 S23 
                 Y Cyl. 
                 All 
                 Glass 
                 497816 
                 SFPL51 
                 OHARA 
                 30.98 
               
               
                   
                   
                   
                 S24 
                 Y Cyl. 
                 All 
                 Air 
                   
                   
                   
                 31.12 
               
               
                 13 
                 G3 
                   
                 S25 
                 Sph. 
                 All 
                 Glass 
                 439950 
                 SFPL53 
                 OHARA 
                 31.53 
               
               
                   
                   
                   
                 S26 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 31.55 
               
               
                 14 
                 G3 
                   
                 S27 
                 Sph. 
                 All 
                 Glass 
                 720347 
                 SNBH8 
                 OHARA 
                 31.26 
               
               
                 15 
                 G3 
                   
                 S28 
                 Sph. 
                 All 
                 Glass 
                 497816 
                 SFPL51 
                 OHARA 
                 30.45 
               
               
                   
                   
                   
                 S29 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 30.34 
               
               
                 16 
                 G3 
                   
                 S30 
                 Sph. 
                 All 
                 Glass 
                 439950 
                 SFPL53 
                 OHARA 
                 29.87 
               
               
                   
                   
                   
                 S31 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 29.38 
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                 17 
                 G4 
                 SG41 
                 S32 
                 Sph. 
                 All 
                 Glass 
                 717479 
                 SLAM3 
                 OHARA 
                 15.48 
               
               
                   
                   
                   
                 S33 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 15.01 
               
               
                 18 
                 G4 
                 SG41 
                 S34 
                 Sph. 
                 All 
                 Glass 
                 589612 
                 SBAL35 
                 OHARA 
                 15.14 
               
               
                 19 
                 G4 
                 SG41 
                 S35 
                 Sph. 
                 All 
                 Glass 
                 805254 
                 SF6 
                 SCHOTT 
                 15.90 
               
               
                   
                   
                   
                 S36 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 16.09 
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                 20 
                 G4 
                 SG42 
                 S37 
                 Sph. 
                 All 
                 Glass 
                 801350 
                 SLAM66 
                 OHARA 
                 18.84 
               
               
                   
                   
                   
                 S38 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 18.83 
               
               
                 21 
                 G4 
                 SG42 
                 S39 
                 Sph. 
                 All 
                 Glass 
                 497816 
                 SFPL51 
                 OHARA 
                 18.95 
               
               
                   
                   
                   
                 S40 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 19.06 
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                   
                 All 
                   
                   
                   
                   
                   
               
               
                 22 
                 G5 
                   
                 S41 
                 Sph. 
                 All 
                 Glass 
                 439950 
                 SFPL53 
                 OHARA 
                 18.30 
               
               
                   
                   
                   
                 S42 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 18.24 
               
               
                 23 
                 G5 
                   
                 S43 
                 Sph. 
                 All 
                 Glass 
                 497816 
                 SFPL51 
                 OHARA 
                 17.95 
               
               
                 24 
                 G5 
                   
                 S44 
                 Sph. 
                 All 
                 Glass 
                 750353 
                 SNI3H51 
                 OHARA 
                 17.49 
               
               
                   
                   
                   
                 S45 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 17.08 
               
               
                 25 
                 G5 
                   
                 S46 
                 Sph. 
                 All 
                 Glass 
                 497816 
                 SFPL51 
                 OHARA 
                 16.91 
               
               
                   
                   
                   
                 S47 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 16.40 
               
               
                 26 
                 G5 
                   
                 S48 
                 Sph. 
                 All 
                 Glass 
                 548458 
                 STIL1 
                 OHARA 
                 15.84 
               
               
                   
                   
                   
                 S49 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 15.14 
               
               
                 Stop 
                   
                   
                 S50 
                 Plano 
                 All 
                 Air 
                   
                   
                   
                 13.55 
               
               
                 27 
                 G5 
                   
                 S51 
                 Sph. 
                 All 
                 Glass 
                 487702 
                 SFSL5 
                 OHARA 
                 10.20 
               
               
                   
                   
                   
                 S52 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 9.93 
               
               
                 28 
                 G5 
                   
                 S53 
                 Sph. 
                 All 
                 Glass 
                 516641 
                 SBSL7 
                 OHARA 
                 10.07 
               
               
                   
                   
                   
                 S54 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 10.16 
               
               
                 29 
                 G5 
                   
                 S55 
                 Sph. 
                 All 
                 Glass 
                 487702 
                 SFSL5 
                 OHARA 
                 10.54 
               
               
                   
                   
                   
                 S56 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 10.84 
               
               
                 30 
                 G5 
                   
                 S57 
                 Sph. 
                 All 
                 Glass 
                 805254 
                 SF6 
                 SCHOTT 
                 13.24 
               
               
                   
                   
                   
                 S58 
                 Sph. 
                 All 
                 Air 
                   
                   
                   
                 12.90 
               
               
                 Image 
                   
                   
                 S59 
                 Y &amp; X Cy 
                 F1 
                 Air 
                   
                   
                   
                   
               
               
                 Surface 
                   
                   
                   
                 Y &amp; X Cy 
                 F2 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F3 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F1 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F2 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F3 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F1 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F2 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F3 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F1 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F2 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F3 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F1 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F2 
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                   
                 Y &amp; X Cy 
                 F3 
               
               
                   
               
               
                 Notes:- 
               
               
                   1 In the Surface Shape column the image surface is not flat to simulate equivalent curved object surfaces through focus distance positions. F1, F2 and F3 and zoom positions Z1, Z2, Z3, Z4 and Z5. 
               
               
                   2 Paraxial focal lengths in the Y-direction at F1 focus position for zoom positions Z1, Z2, Z3, Z4 and Z5 respectively are 40.01 mm, 51.00 mm, 67.98 mm, 95.45 mm and 125.01 mm. 
               
               
                   3 Paraxial focal lengths in the X-direction at F1 focus position for zoom positions Z1, Z2, Z3, Z4 and Z5 respectively are 20.57 mm, 26.21 mm, 34.94 mm, 49.06 mm and 64.27 mm. 
               
               
                   4 In the Material Name column the trade name of the lens material used is given. 
               
               
                   5 In the Material Supplier column a manufacturer name is given although there may be alternative manufacturers. 
               
               
                   6 The data given in the Aperture Half Diameter column is for circular apertures. 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Focal Length, Anamorphic Squeeze, Illumination and Breathing 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                   
                 Paraxial 
                 Focal 
                 Anamorphic 
                 Relative 
                   
               
               
                   
                 Focus 
                 Y 
                 X 
                 Squeeze 
                 Illumination 2   
                   
               
               
                 Zoom Position 
                 Position 
                 Direction 
                 Direction 
                 Ratio 1   
                 (%) 
                 Breathing 3   
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Z1 
                 F1 
                 40.01 
                 20.57 
                 1.946 
                 30.1 
                 0.0 
               
               
                   
                 F2 
                 40.16 
                 20.29 
                 1.980 
                 30.9 
                 +0.4 
               
               
                   
                 F3 
                 40.33 
                 20.04 
                 2.013 
                 30.8 
                 +0.8 
               
               
                 Z3 
                 F1 
                 67.98 
                 34.94 
                 1.946 
                 30.1 
                 0.0 
               
               
                   
                 F2 
                 68.65 
                 34.52 
                 1.989 
                 30.1 
                 +1.0 
               
               
                   
                 F3 
                 69.35 
                 34.15 
                 2.031 
                 30.1 
                 +2.0 
               
               
                 Z5 
                 F1 
                 125.01 
                 64.27 
                 1.945 
                 30.6 
                 0.0 
               
               
                   
                 F2 
                 123.15 
                 63.09 
                 1.952 
                 30.6 
                 −1.5 
               
               
                   
                 F3 
                 121.48 
                 62.03 
                 1.958 
                 30.6 
                 −2.8 
               
               
                   
               
               
                   1 Based on paraxial focal length in Y direction divided by paraxial focal length in X direction. 
               
               
                   2 At maximum radial image distance from the optical axis which is at the corner of the image. 
               
               
                   3 Based on the percentage difference between the paraxial effective focal length in the Y-direction at focus position F1 and focus positions F2 and F3. 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 MTF Performance Data 
               
            
           
           
               
               
            
               
                 FIELD POSITION 
                   
               
            
           
           
               
               
               
            
               
                 Image 
                 Normalized 
                   
               
               
                 Height 
                 Image Height 
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 X-direction 
                 Y-direction 
                 X-direction 
                 Y-direction 
                 FOCUS POSITIONS (F) AND ZOOM POSITIONS (Z) 
                 PERFORMANCE DATA 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 (mm) 
                 (mm) 
                 (mm) 
                 (mm) 
                 F1, Z1 
                 F3, Z1 
                 F2, Z3 
                 F1, Z5 
                 F2, Z5 
                 F3, Z5 
                 Description 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 0 
                 0 
                 0 
                 91.0 (R) 
                 90.9 (R) 
                 89.7 (R) 
                 74.7 (R) 
                 75.4 (R) 
                 78.2 (R) 
                 Polychromatic diffraction 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Axial) 
                 (Axial) 
                 92.2 (T) 
                 92.1 (T) 
                 92.6 (T) 
                 64.2 (T) 
                 72.1 (T) 
                 73.1 (T) 
                 MTF data (%) 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 8.91 
                 0 
                 1 
                 87.1 (R) 
                 89.8 (R) 
                 89.5 (R) 
                 82.2 (R) 
                 59.8 (R) 
                 79.8 (R) 
                 at 20 cycles/mm at image 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Top of Field) 
                 (Top of Field) 
                 72.5 (T) 
                 69.3 (T) 
                 75.7 (T) 
                 78.8 (T) 
                 74.4 (T) 
                 69.2 (T) 
                 surfaces and at the following 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 10.65 
                 0 
                 1 
                 0 
                 63.5 (R) 
                 67.1 (R) 
                 64.5 (R) 
                 57.6 (R) 
                 54.2 (R) 
                 65.8 (R) 
                 wavelengths 656.3, 587.6, 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Side of Field) 
                 (Side of Field) 
                 85.9 (T) 
                 88.3 (T) 
                 82.6 (T) 
                 53.4 (T) 
                 65.7 (T) 
                 80.7 (T) 
                 546.1, 486.1 and 455.0 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 7.47 
                 6.24 
                 0.7 
                 0.7 
                 74.2 (R) 
                 74.7 (R) 
                 81.1 (R) 
                 80.0 (R) 
                 82.3 (R) 
                 79.6 (R) 
                 nanometers with respective 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (70% Corner to Field) 
                 (70% Corner of Field) 
                 78.6 (T) 
                 78.6 (T) 
                 83.9 (T) 
                 64.7 (T) 
                 75.3 (T) 
                 77.4 (T) 
                 weightings 7, 8, 9, 7 and 4, 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 10.65 
                 8.91 
                 1 
                 1 
                 67.1 (R) 
                 66.1 (R) 
                 57.6 (R) 
                 53.1 (R) 
                 63.5 (R) 
                 71.7 (R) 
                 where (R) = radial and (T) = 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Corner of Field) 
                 (Corner of Field) 
                 75.3 (T) 
                 74.8 (T) 
                 78.1 (T) 
                 54.0 (T) 
                 62.1 (T) 
                 62.9 (T) 
                 tangential azimuths 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 MTF Performance Data 
               
            
           
           
               
               
            
               
                 FIELD POSITION 
                   
               
            
           
           
               
               
               
            
               
                 Image 
                 Normalized 
                   
               
               
                 Height 
                 Image Height 
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 X-direction 
                 Y-direction 
                 X-direction 
                 Y-direction 
                 FOCUS POSITIONS (F) AND ZOOM POSITIONS (Z) 
                 PERFORMANCE DATA 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 (mm) 
                 (mm) 
                 (mm) 
                 (mm) 
                 F1, Z1 
                 F3, Z1 
                 F2, Z3 
                 F1, Z5 
                 F2, Z5 
                 F3, Z5 
                 Description 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 0 
                 0 
                 0 
                 90.3 (R) 
                 90.3 (R) 
                 89.3 (R) 
                 73.2 (R) 
                 74.0 (R) 
                 76.9 (R) 
                 Polychromatic diffraction 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Axial) 
                 (Axial) 
                 91.5 (T) 
                 91.8 (T) 
                 93.2 (T) 
                 64.6 (T) 
                 74.9 (T) 
                 74.1 (T) 
                 MTF data (%) 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 8.91 
                 0 
                 1 
                 87.9 (R) 
                 89.6 (R) 
                 89.8 (R) 
                 82.7 (R) 
                 61.2 (R) 
                 82.1 (R) 
                 at 20 cycles/mm at image 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Top of Field) 
                 (Top of Field) 
                 70.5 (T) 
                 67.0 (T) 
                 73.5 (T) 
                 79.8 (T) 
                 71.6 (T) 
                 65.6 (T) 
                 surfaces and at the following 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 10.65 
                 0 
                 1 
                 0 
                 62.1 (R) 
                 65.6 (R) 
                 64.5 (R) 
                 57.1 (R) 
                 52.2 (R) 
                 63.3 (R) 
                 wavelengths 656.3, 587.6, 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Side of Field) 
                 (Side of Field) 
                 86.9 (T) 
                 88.5 (T) 
                 85.1 (T) 
                 54.1 (T) 
                 70.4 (T) 
                 82.2 (T) 
                 546.1, 486.1 and 455.0 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 7.47 
                 6.24 
                 0.7 
                 0.7 
                 73.3 (R) 
                 73.7 (R) 
                 80.5 (R) 
                 79.6 (R) 
                 81.4 (R) 
                 78.1 (R) 
                 nanometers with respective 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (70% Corner to Field) 
                 (70% Corner of Field) 
                 77.6 (T) 
                 77.3 (T) 
                 84.9 (T) 
                 66.1 (T) 
                 77.1 (T) 
                 77.4 (T) 
                 weightings 7, 8, 9, 7 and 4, 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 10.65 
                 8.91 
                 1 
                 1 
                 67.9 (R) 
                 66.7 (R) 
                 58.3 (R) 
                 54.0 (R) 
                 64.4 (R) 
                 71.5 (R) 
                 where (R) = radial and (T) = 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Corner of Field) 
                 (Corner of Field) 
                 74.3 (T) 
                 73.7 (T) 
                 77.4 (T) 
                 53.4 (T) 
                 612 (T) 
                 61.3 (T) 
                 tangential azimuths 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 MTF Performance Data 
               
            
           
           
               
               
            
               
                 FIELD POSITION 
                   
               
            
           
           
               
               
               
            
               
                 Image 
                 Normalized 
                   
               
               
                 Height 
                 Image Height 
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 X-direction 
                 Y-direction 
                 X-direction 
                 Y-direction 
                 FOCUS POSITIONS (F) AND ZOOM POSITIONS (Z) 
                 PERFORMANCE DATA 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 (mm) 
                 (mm) 
                 (mm) 
                 (mm) 
                 F1, Z1 
                 F3, Z1 
                 F2, Z3 
                 F1, Z5 
                 F2, Z5 
                 F3, Z5 
                 Description 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 0 
                 0 
                 0 
                 91.3 (R) 
                 90.9 (R) 
                 90.4 (R) 
                 77.2 (R) 
                 77.9 (R) 
                 80.3 (R) 
                 Polychromatic diffraction 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Axial) 
                 (Axial) 
                 92.9 (T) 
                 92.0 (T) 
                 92.2 (T) 
                 62.5 (T) 
                 68.3 (T) 
                 70.4 (T) 
                 MTF data (%) 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 8.91 
                 0 
                 1 
                 85.5 (R) 
                 89.6 (R) 
                 88.8 (R) 
                 79.7 (R) 
                 55.7 (R) 
                 87.6 (R) 
                 at 20 cycles/mm at image 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Top of Field) 
                 (Top of Field) 
                 73.6 (T) 
                 70.8 (T) 
                 76.4 (T) 
                 77.2 (T) 
                 77.6 (T) 
                 71.1 (T) 
                 surfaces and at the following 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 10.65 
                 0 
                 1 
                 0 
                 64.7 (R) 
                 68.3 (R) 
                 64.0 (R) 
                 58.1 (R) 
                 56.8 (R) 
                 68.5 (R) 
                 wavelengths 656.3, 587.6, 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Side of Field) 
                 (Side of Field) 
                 84.1 (T) 
                 87.7 (T) 
                 80.3 (T) 
                 51.6 (T) 
                 70.9 (T) 
                 77.6 (T) 
                 546.1, 486.1 and 455.0 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 7.47 
                 6.24 
                 0.7 
                 0.7 
                 75.3 (R) 
                 75.7 (R) 
                 81.4 (R) 
                 80.0 (R) 
                 83.0 (R) 
                 81.2 (R) 
                 nanometers with respective 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (70% Corner to Field) 
                 (70% Corner of Field) 
                 79.4 (T) 
                 79.5 (T) 
                 83.1 (T) 
                 61.9 (T) 
                 72.7 (T) 
                 76.0 (T) 
                 weightings 7, 8, 9, 7 and 4, 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 10.65 
                 8.91 
                 1 
                 1 
                 65.2 (R) 
                 64.0 (R) 
                 55.9 (R) 
                 50.3 (R) 
                 61.3 (R) 
                 71.4 (R) 
                 where (R) = radial and (T) = 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 (Corner of Field) 
                 (Corner of Field) 
                 75.1 (T) 
                 75.1 (T) 
                 78.3 (T) 
                 52.7 (T) 
                 61.4 (T) 
                 62.2 (T) 
                 tangential azimuths