Patent Publication Number: US-2023164435-A1

Title: Electronic device, control method of the same, and storage medium

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of International Patent Application No. PCT/JP2021/025780, filed Jul. 8, 2021, which claims the benefit of Japanese Patent Application No. 2020-125163, filed Jul. 22, 2020, both of which are hereby incorporated by reference herein in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an electronic device, a control method of the electronic device, and a storage medium, and relates particularly to a technique of performing image capturing via a plurality of lenses. 
     Background Art 
     There has been electronic devices that can perform image capturing from the rear side and the front side of the electronic device. PTL1 describes that a plurality of cameras can be moved in such a manner as to be arranged on both of the rear surface and the front surface of an electronic device. 
     CITATION LIST 
     Patent Literature 
     PTL1: Japanese Patent Application Laid-Open No. 2012-222471 
     The method described in PTL1 does not change a field angle in accordance with a direction that a camera faces, and thus a photographer might fail to swiftly perform image capturing at a field angle desired by the photographer, in a case where the photographer itself serves as a subject and desires to perform image capturing at a wide field angle. 
     SUMMARY OF THE INVENTION 
     In view of the above-described issues, the present invention provides an electronic device that can set a field angle with good operability in a case where a photographer itself serves as a subject. 
     To achieved the above-described purpose, an electronic device of the present invention is an electronic device having a first surface and a second surface, and includes lens switching means that can switch between image capturing performed using a first lens arranged on the first surface, and image capturing performed using a second lens being capable of executing image capturing at a wider angle than an angle of the first lens, first instruction means for issuing an instruction to display, on a display unit, a captured image acquired via a lens arranged on the first surface, second instruction means for issuing an instruction to display, on the display unit, a captured image acquired via a lens arranged on the second surface that at least includes a third lens, switching means that can switch, on the second surface, between image capturing at a first field angle and image capturing at a second field angle wider than the first field angle, and control means for controlling a captured image acquired via the first lens to be displayed on the display unit in a case where an instruction to display a captured image is issued by the first instruction means, and controlling a captured image at the second field angle to be displayed on the display unit in a case where an instruction to display a captured image is issued by the second instruction means. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The attached drawings are included in the specification, constitute a part thereof, illustrate an exemplary embodiment of the present invention, and are used to describe the principle of the present invention together with the description thereof. 
         FIG.  1 A  is an external view of a smartphone serving as an example of an apparatus to which a configuration of the present exemplary embodiment can be applied. 
         FIG.  1 B  is an external view of the smartphone serving as the example of the apparatus to which the configuration of the present exemplary embodiment can be applied. 
         FIG.  2    is a block diagram illustrating a configuration example of a smartphone serving as an example of an apparatus to which a configuration of the present exemplary embodiment can be applied. 
         FIG.  3 A  is a diagram illustrating each lens unit of a smartphone  100  according to the present exemplary embodiment. 
         FIG.  3 B  is a diagram illustrating each lens unit of the smartphone  100  according to the present exemplary embodiment. 
         FIG.  4 A  is a diagram illustrating each lens unit of a smartphone  100  according to the present exemplary embodiment. 
         FIG.  4 B  is a diagram illustrating each lens unit of the smartphone  100  according to the present exemplary embodiment. 
         FIG.  5 A  is a flowchart illustrating image capturing control processing according to the present exemplary embodiment. 
         FIG.  5 B  is a flowchart illustrating image capturing control processing according to the present exemplary embodiment. 
         FIG.  6 A  is a flowchart illustrating image capturing control processing of a front camera according to the present exemplary embodiment. 
         FIG.  6 B  is a flowchart illustrating image capturing control processing of a front camera according to the present exemplary embodiment. 
         FIG.  7 A  is a diagram illustrating an example of display in image capturing control processing. 
         FIG.  7 B  is a diagram illustrating an example of display in image capturing control processing. 
         FIG.  7 C  is a diagram illustrating an example of display in image capturing control processing. 
         FIG.  7 D  is a diagram illustrating an example of display in image capturing control processing. 
         FIG.  7 E  is a diagram illustrating an example of display in image capturing control processing. 
         FIG.  7 F  is a diagram illustrating an example of display in image capturing control processing. 
         FIG.  7 G  is a diagram illustrating an example of display in image capturing control processing. 
         FIG.  7 H  is a diagram illustrating an example of display in image capturing control processing. 
         FIG.  7 I  is a diagram illustrating an example of display in image capturing control processing. 
         FIG.  7 J  is a diagram illustrating an example of display in image capturing control processing. 
         FIG.  7 K  is a diagram illustrating an example of display in image capturing control processing. 
         FIG.  8 A  is a flowchart illustrating image capturing mode selection processing according to the present exemplary embodiment. 
         FIG.  8 B  is a flowchart illustrating image capturing mode selection processing according to the present exemplary embodiment. 
         FIG.  8 C  is a flowchart illustrating image capturing mode selection processing according to the present exemplary embodiment. 
         FIG.  9    is a flowchart illustrating image capturing mode selection processing of a front camera according to the present exemplary embodiment. 
         FIG.  10 A  is a diagram illustrating an example of display in image capturing mode selection processing. 
         FIG.  10 B  is a diagram illustrating an example of display in image capturing mode selection processing. 
         FIG.  10 C  is a diagram illustrating an example of display in image capturing mode selection processing. 
         FIG.  10 D  is a diagram illustrating an example of display in image capturing mode selection processing. 
         FIG.  10 E  is a diagram illustrating an example of display in image capturing mode selection processing. 
         FIG.  11 A  is a diagram illustrating an example of display in image capturing mode selection processing. 
         FIG.  11 B  is a diagram illustrating an example of display in image capturing mode selection processing. 
         FIG.  11 C  is a diagram illustrating an example of display in image capturing mode selection processing. 
         FIG.  11 D  is a diagram illustrating an example of display in image capturing mode selection processing. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, a preferred exemplary embodiment of the present invention will be described with reference to the drawings. 
       FIGS.  1 A and  1 B  are external views of a smartphone  100  serving as an example of an electronic device of the present invention.  FIG.  1 A  illustrates a rear surface on an opposite side of a display surface of the smartphone  100 , and  FIG.  1 B  illustrates a display surface side of the smartphone  100 . 
     A display unit  28  is a display unit that displays images and various types of information, and includes a touch panel  70   a  that can detect a touch operation performed on the display unit  28 . An up key  61  is a button that can issue a volume increase instruction and an image capturing instruction. A down key  60  is a button that that can issue a volume decrease instruction, and a recording instruction of an image displayed on the display unit  28 , by being pressed concurrently with a power switch  72 . The power switch  72  is a push button for switching between power on and power off. Three lens units are arranged on a first surface (rear surface) being a side on which the display unit  28  of the smartphone  100  is not provided, and two cameras are arranged on a second surface (front surface) being a side on which the display unit  28  is provided. The respective focal lengths of lens units and cameras are different, and thus measures of field angles at which the lens units and the cameras can perform image capturing are different. By switching a lens between a lens arranged on the first surface and a lens arranged on the second surface, the user can change whether to stand on the display unit  28  side and capture an image including the user holding the smartphone  100 . In addition, by using a lens arranged on the second surface, the user can perform image capturing while checking an image being captured, on the display unit  28 . 
       FIG.  2    is a block diagram illustrating a configuration example of the smartphone  100  according to the present exemplary embodiment. 
     The smartphone  100  includes lens units  201  to  205 . The lens units  201  and  202  are arranged on the second surface, and the lens units  203 ,  204 , and  205  are arranged on the first surface. Lenses  103   a  to  103   e  indicate lenses included in the respective lens units. Some of the lens units include a plurality of lenses, but  FIG.  2    illustrates only one lens as a lens included in each lens unit, for the sake of simplification. 
     The lens unit  201  is a standard lens and the lens unit  202  is a wide-angle lens. When a lens of the lens unit  202  is used, it becomes possible to capture an image at a wider field angle than an image captured when a lens of the lens unit  201  is used. The lens unit  203  is a standard lens, the lens unit  204  is a wide-angle lens, and the lens unit  205  is a super-wide-angle lens. The lens unit  204  can capture an image at a wider field angle than the lens unit  203 , and the lens unit  205  can capture an image at a wider field angle than the lens unit  204 . Alternatively, in a case where lenses arranged on the first surface are a standard lens, a wide-angle lens, and a telephoto lens, the following configuration is employed. 
     The lens unit  201  is a standard lens and the lens unit  202  is a wide-angle lens. When a lens of the lens unit  202  is used, it becomes possible to capture an image at a wider field angle than an image captured when a lens of the lens unit  201  is used. The lens unit  203  is a telephoto lens, the lens unit  204  is a standard lens, and the lens unit  205  is a wide-angle lens. The lens unit  204  can capture an image at a wider field angle than the lens unit  203 , and the lens unit  205  can capture an image at a wider field angle than the lens unit  204 . 
     The following configurations are obtained as follows irrespective of the types of lenses arranged on the first surface. 
     Shutters  101   a  to  101   e  are shutters having a diaphragm function. Imaging units  22   a  to  22   e  are image sensors each including a charge-coupled device (CCD) sensor or a complementary metal-oxide semiconductor (CMOS) sensor that converts an optical image into an electric signal. An analog-to-digital (A/D) converter  23  is used to convert analog signals output from the imaging units  22  into digital signals. 
     A CCD sensor or a CMOS sensor is typically used for the image sensors. The image sensors photoelectrically convert a subject image formed on the image sensors through the lens units  201  to  205 , and output the converted subject image as an electric signal. 
     An image processing unit  24  performs resize processing, such as predetermined pixel interpolation or reduction, and color conversion processing, on data from the A/D converter  23  or data from a memory control unit  15 . The image processing unit  24  also performs predetermined calculation processing using data of a captured image. A system control unit  50  performs exposure control and ranging control based on the obtained calculation result. Through-the-lens (TTL) system autofocus (AF) processing, autoexposure (AE) processing, and electronic flash pre-emission (EF) processing are thereby performed. The image processing unit  24  further performs predetermined calculation processing using data of a captured image, and also performs TTL system automatic white balance (AWB) processing based on the obtained calculation result. 
     Output data from the A/D converter  23  is directly written into a memory  32  via the image processing unit  24  and the memory control unit  15 , or via the memory control unit  15 . The memory  32  stores image data obtained by the imaging unit  22  and converted by the A/D converter  23  into digital data, and image data to be displayed on the display unit  28 . The memory  32  has a storage capacity sufficient for storing a predetermined number of still images, and a predetermined time length of a moving image and voice. 
     A power source control unit  80  includes a battery detection circuit, a direct current (DC)-DC converter, and a switch circuit for switching a block to be supplied with power. The power source control unit  80  detects whether a battery is attached, the type of the battery, and remaining battery capacity. The power source control unit  80  also controls the DC-DC converter based on the detection result and an instruction from the system control unit  50 , and supplies necessary voltage to components including a recording medium  200 , for a necessary time period. If the power switch  72  is long-pressed (continuously pressed for more than a predetermined time such as two or three seconds), it is possible to switch between ON and OFF of the power of the smartphone  100 . In addition, if the power switch  72  is pressed for a short period smaller than the predetermined time, it is possible to switch between a nondisplay state and a display state of the display on the display unit  28 . 
     A power source unit  30  includes a primary battery, such as an alkaline battery or a lithium battery, a secondary battery, such as a nickel-cadmium (NiCd) battery, a nickel-metal hydride (NiMH) battery, or a lithium (Li) battery, and an alternating current (AC) adapter. 
     A recording medium interface (I/F)  18  is an interface to the recording medium  200 , such as a memory card or a hard disc. The recording medium  200  is a recording medium, such as a memory card, for recording captured images, downloaded music, and videos, and includes a semiconductor memory or a magnetic disc. 
     A communication unit  54  is connected wirelessly or via a wired cable, and transmits or receives a video signal and an audio signal. The communication unit  54  can also be connected with a wireless local area network (LAN) and the Internet. The communication unit  54  can transmit an image (including a live view) captured by the imaging unit  22  and an image recorded on the recording medium  200 . The communication unit  54  can also receive image data and other various types of information from an external device. 
     An orientation detection unit  55  detects the orientation of the smartphone  100  with respect to a direction of gravitational force. Based on the orientation detected by the orientation detection unit  55 , it can be determined whether an image captured by the imaging unit  22  is an image captured with the smartphone  100  being held in a traverse direction or an image captured with the smartphone  100  being held in a longitudinal direction. The system control unit  50  can add orientation information corresponding to the orientation detected by the orientation detection unit  55 , to an image file of an image captured by the imaging unit  22 , or record an image with being rotated. As the orientation detection unit  55 , an acceleration sensor or a gyro sensor can be used. 
     A system timer  53  is a time measuring unit for measuring a time used for various types of control or a time of a built-in clock. 
     A down key  60 , an up key  61 , and an operation unit  70  function as operating means for inputting various operation instructions to the system control unit  50 . 
     Constants and variables for operating the system control unit  50 , and programs read out from a nonvolatile memory  56  are loaded onto a system memory  52 . The system control unit also performs display control by controlling the memory  32 , a digital-to-analog (D/A) converter  13 , and the display unit  28  by using a random access memory (RAM). 
     The nonvolatile memory  56  is a memory electrically-erasable/recordable by the system control unit  50 , and for example, an electrically erasable programmable read-only memory (EEPROM) is used for the nonvolatile memory  56 . Constants for operating the system control unit  50  and programs are stored in the nonvolatile memory  56 . Herein, the programs refer to programs for executing various flowcharts to be described below in the present exemplary embodiment. 
     The system control unit  50  includes at least one processor, and controls the entire smartphone  100 . The system control unit  50  implements each piece of processing in the present exemplary embodiment, which will be described below by executing the above-described program recorded in the nonvolatile memory  56 . 
     The operation unit  70  includes the touch panel  70   a  that can detect a touch operation, and a switch for switching a mode to a silent mode. The operation unit  70  further includes the up key  61 , the down key  60 , and the power switch  72 . 
     The memory  32  also serves as a memory (video memory) for image display. The D/A converter  13  converts data for image display that is stored in the memory  32 , into an analog signal, and supplies the analog signal to the display unit  28 . The image data for display that is written into the memory  32  in this manner is displayed by the display unit  28  via the D/A converter  13 . The display unit  28  performs display according to the analog signal from the D/A converter  13 , on a display device, such as a liquid crystal display (LCD). The digital signals having been once A/D-converted by the A/D converter  23  and stored in the memory  32  are D/A-converted by the D/A converter  13 , and sequentially transferred to the display unit  28  and displayed thereon. This enables a function as an electronic viewfinder to perform a live view display. 
       FIGS.  3 A,  3 B,  4 A, and  4 B  are diagrams illustrating an image capturing field angle, a focal length, and a display magnification of each lens unit of the smartphone  100 .  FIGS.  3 A and  3 B  illustrate a case where a rear camera on the first surface includes a super-wide-angle lens, a wide-angle lens, and a standard lens, and a front camera on the second surface includes a wide-angle lens and a standard lens. 
       FIG.  3 A  illustrates lenses included in each of the lens units corresponding to lens units (rear camera) on the first surface and lens units (front camera) on the second surface. In the lens units on the first surface, a super-wide-angle lens corresponding to the lens unit  205  has a focal length of 10 mm and an image capturing field angle of 130 degrees. In addition, a wide-angle lens corresponding to the lens unit  204  has a focal length of 20 mm and an image capturing field angle of 80 degrees, and a standard lens corresponding to the lens unit  203  has a focal length of 30 mm and an image capturing field angle of 60 degrees. In the lens units on the second surface, a wide-angle lens corresponding to the lens unit  202  has a focal length of 15 mm and an image capturing field angle of 110 degrees, and a standard lens corresponding to the lens unit  201  has a focal length of 25 mm and an image capturing field angle of 70 degrees. 
     In the lens units on the first surface, an image is captured by the lens unit  205  at an image capturing field angle of 130 degrees, and in a case where a designated image capturing field angle is smaller than 130 degrees and larger than 80 degrees, an image capturing field angle is narrowed using electronic zoom. If an image capturing field angle reaches an image capturing field angle of 80 degrees, image capturing switches to image capturing by a lens of the lens unit  204 . Furthermore, an image is captured by the lens unit  204  at an image capturing field angle of 80 degrees, and in a case where a designated image capturing field angle is smaller than 80 degrees and larger than 60 degrees, an image capturing field angle is narrowed using electronic zoom. If a designated image capturing field angle reaches an image capturing field angle of 60 degrees, image capturing switches to image capturing by a lens of the lens unit  203 . A designation method of an image capturing field angle will be described below. By switching a lens, the user can change a field angle of a captured image. In this manner, if a field angle change instruction is issued by the user, while using electronic zoom, a lens unit that performs image capturing is switched at a timing at which an instruction to change a field angle to an image capturing field angle at which a neighboring lens unit can perform image capturing is issued. Similarly, also in the case of the second surface, an image is captured by the lens unit  202  at an image capturing field angle of 110 degrees, and if a designated image capturing field angle becomes smaller than 110 degrees and larger than 70 degrees, an image capturing field angle is narrowed using electronic zoom. A captured image at a designated field angle (captured image via a lens suitable for a designated field angle) is displayed on the display unit  28 . If a designated image capturing field angle reaches 70 degrees, image capturing switches to image capturing by a lens of the lens unit  201 . In the present exemplary embodiment, each lens needs not be a single focus lens, and may have a configuration in which a lens position is changeable and optical zoom can be performed. 
       FIG.  3 B  is a diagram illustrating switching of a lens unit on the first surface that is performed in a case where a lens unit can perform optical zoom. In the lens units on the first surface, an image is captured by the lens unit  205  at an image capturing field angle of 130 degrees, and if a designated image capturing field angle becomes smaller than 130 degrees, optical zoom is initially performed by moving the position of a lens. Then, if a designated image capturing field angle reaches 110 degrees, an image capturing field angle is narrowed using electronic zoom. If the image capturing field angle reaches an image capturing field angle of 80 degrees, image capturing switches to image capturing by a lens of the lens unit  204 . Furthermore, if a designated image capturing field angle becomes smaller than 80 degrees, an image capturing field angle is changed using optical zoom, and if a designated image capturing field angle becomes smaller than 70 degrees, electronic zoom is performed. If a designated image capturing field angle reaches 60 degrees, image capturing is performed using the lens unit  203 . If a designated image capturing field angle becomes smaller than 60 degrees, electronic zoom is performed using the lens unit  203 . A configuration may be employed in which only single focus lenses are used as lenses of a front camera on the second surface and lenses of a rear camera on the first surface can perform optical zoom. In addition, both in the case illustrated in  FIG.  3 A  and the case illustrated in  FIG.  3 B , a timing at which a lens unit that performs image capturing is switched to scale back an image capturing field angle needs not be always consistent with a timing at which a lens unit is switched to scale up an image capturing field angle. A switch timing of a lens unit that performs image capturing may be changed in such a manner as to scale back the influence on a captured image, in accordance with an image capturing mode and an image capturing situation. 
       FIGS.  4 A and  4 B  illustrate a case where a rear camera on the first surface includes a wide-angle lens, a standard lens, and a telephoto lens, and a front camera on the second surface includes a wide-angle lens and a standard lens. 
       FIG.  4 A  illustrates lenses included in each of the lens units corresponding to lens units (rear camera) on the first surface and lens units (front camera) on the second surface. In the lens units on the first surface, a wide-angle lens corresponding to the lens unit  205  has a focal length of 15 mm and an image capturing field angle of 110 degrees. In addition, a standard lens corresponding to the lens unit  204  has a focal length of 20 mm and an image capturing field angle of 80 degrees, and a telephoto lens corresponding to the lens unit  203  has a focal length of 80 mm and an image capturing field angle of 20 degrees. In the lens units on the second surface, a wide-angle lens corresponding to the lens unit  202  has a focal length of 20 mm and an image capturing field angle of 110 degrees, and a standard lens corresponding to the lens unit  201  has a focal length of 30 mm and an image capturing field angle of 70 degrees. 
     In the lens units on the first surface, an image is captured by the lens unit  205  at an image capturing field angle of 110 degrees, and in a case where a designated image capturing field angle is smaller than 110 degrees and larger than 80 degrees, an image capturing field angle is narrowed using electronic zoom. If an image capturing field angle reaches an image capturing field angle of 80 degrees, image capturing switches to image capturing by a lens of the lens unit  204 . Furthermore, an image is captured by the lens unit  204  at an image capturing field angle of 80 degrees, and in a case where a designated image capturing field angle is smaller than 80 degrees and larger than 30 degrees, an image capturing field angle is narrowed using electronic zoom. Nevertheless, a timing at which a lens is switched to a telephoto lens needs not be always a timing at which a designated image capturing field angle becomes 20 degrees. If a designated image capturing field angle reaches 20 degrees, and image capturing switches to image capturing by a lens of the lens unit  203 . A designation method of an image capturing field angle will be described below. In this manner, if a field angle change instruction is issued by the user, while using electronic zoom, a lens unit that performs image capturing is switched at a timing at which an instruction to change a field angle to an image capturing field angle at which a neighboring lens unit can perform image capturing is issued. Similarly, also in the case of the second surface, an image is captured by the lens unit  202  at an image capturing field angle of 110 degrees, and if a designated image capturing field angle becomes smaller than 110 degrees and larger than 70 degrees, an image capturing field angle is narrowed using electronic zoom. If a designated image capturing field angle reaches 70 degrees, image capturing switches to image capturing by a lens of the lens unit  201 . In the present exemplary embodiment, each lens needs not be a single focus lens, and may have a configuration in which a lens position is movable and optical zoom can be performed. 
       FIG.  4 B  is a diagram illustrating switching of a lens unit on the first surface that is performed in a case where a lens unit can perform optical zoom. In the lens units on the first surface, an image is captured by the lens unit  205  at an image capturing field angle of 130 degrees, and if a designated image capturing field angle becomes smaller than 130 degrees, optical zoom is initially performed by moving the position of a lens. Then, if a designated image capturing field angle reaches 110 degrees, an image capturing field angle is narrowed using electronic zoom. If an image capturing field angle reaches an image capturing field angle of 80 degrees, image capturing switches to image capturing by a lens of the lens unit  204 . Furthermore, if a designated image capturing field angle becomes smaller than 80 degrees, an image capturing field angle is changed using optical zoom, and if a designated image capturing field angle becomes smaller than 70 degrees, electronic zoom is performed. If a designated image capturing field angle reaches 20 degrees, image capturing is performed using the lens unit  203 . If a designated image capturing field angle becomes smaller than 20 degrees, electronic zoom is performed using the lens unit  203 . A configuration may be employed in which only single focus lenses are used as lenses of a front camera on the second surface, and lenses of a rear camera on the first surface can perform optical zoom. In addition, both in the case illustrated in  FIG.  4 A  and the case illustrated in  FIG.  4 B , a timing at which a lens unit that performs image capturing is switched to scale back an image capturing field angle needs not be always consistent with a timing at which a lens unit is switched to scale up an image capturing field angle. A switch timing of a lens unit that performs image capturing may be changed in such a manner as to scale back the influence on a captured image, in accordance with an image capturing mode and an image capturing situation. 
     Next, image capturing control processing according to the present exemplary embodiment will be described with reference to flowcharts in  FIGS.  5 A,  5 B,  6 A and  6 B . The processing is implemented by loading a program recorded in the nonvolatile memory  56 , onto the system memory  52 , and the system control unit  50  executing the program. The processing starts when the power of the smartphone  100  is turned on. The image capturing control processing illustrated in  FIGS.  5 A,  5 B,  6 A and  6 B  is premised on a case where a rear camera on the first surface includes a wide-angle lens, a standard lens, and a telephoto lens, and a front camera on the second surface includes a wide-angle lens and a standard lens. In other words, the description will be given assuming that the lens units illustrated in  FIGS.  4 A and  4 B  are arranged on a smartphone, but the configuration is not limited to this. 
     In step S 501 , the system control unit  50  determines whether a camera function start-up instruction has been issued. The camera function start-up instruction can be issued by touching an item of a camera that is displayed on the display unit  28 . In a case where it is determined that a camera function start-up instruction has been issued (YES in step S 501 ), the processing proceeds to step S 502 . In a case where it is determined that a camera function start-up instruction has not been issued (NO in step S 501 ), the processing proceeds to step S 503 . 
     In step S 502 , the system control unit  50  starts up the standard lens among lenses of the rear camera on the first surface. That is, the system control unit  50  starts up the camera of the lens unit  204 . In other words, if the camera function is started up, the rear camera starts up. As described below, after the rear camera starts up, the rear camera can be switched to a camera on the second surface (i.e., front camera). 
     In step S 503 , the system control unit  50  performs other processing. Examples of the other processing include reproduction of images acquired via the lens units  201  to  205 , browsing on the Internet, and editing of images. 
     In step S 504 , the system control unit  50  sequentially displays, on the display unit  28 , captured images acquired via the lens unit  204  (live view image). 
     In step S 505 , the system control unit  50  displays an image capturing setting available to the standard lens (the lens unit  204 ).  FIGS.  7 A to  7 K  each illustrate an example of display in the image capturing control processing illustrated in  FIGS.  5 A,  5 B,  6 A and  6 B .  FIG.  7 A  illustrates a display example of the display unit  28  to be displayed when the rear camera is started up. An item  704  is an item for changing an aperture value, and an item  705  is an item for changing a beautiful skin effect. When an image including a person is captured by the standard lens of the rear camera, there is a possibility that a face appears big. It is therefore desirable that the beautiful skin effect is provided. In addition, an item  702  illustrated in  FIG.  7 A  is an item for issuing an image capturing instruction, and an item  703  is an item for switching to image capturing by the front camera. Items  700  and  708  to  710  are items for switching an image capturing mode. When the camera starts up, a photo mode indicated by the item  700  is selected, but the camera can start up in a state in which an image capturing mode set when the user starts up the camera lastly is selected. The item  708  indicates a video mode, and it becomes possible to capture a movie. The item  709  indicates a portrait mode, and it becomes possible to capture an image in a state in which a subject on the background of a main subject is blurred. The item  710  indicates a time-lapse mode. In the time-lapse mode, images are consecutively reproduced by performing image capturing every predetermined time, such as two seconds or five seconds. 
     In step S 506 , the system control unit  50  displays “1.0× (1×)” on the display unit  28  as an image capturing magnification. As illustrated in  FIG.  7 A , an item  701  indicates a magnification of current image capturing, and “1.0×” is displayed at the time of start-up. In other words, in a case where an image capturing field angle of image capturing performed using the standard lens illustrated in  FIG.  4 A  is 80 degrees, an image capturing magnification is displayed as 1.0×. In other words, by displaying “1.0×” as a field angle set when electronic zoom is not performed by the standard lens, the user can recognize that a field angle can be changed by scaling back or up the field angle with respect to a currently displayed field angle. 
     In step S 507 , the system control unit  50  determines whether an instruction to switch to the wide-angle lens has been issued. In a case where it is determined that an instruction to switch to the wide-angle lens has been issued (YES in step S 507 ), the processing proceeds to step S 508 . In a case where it is determined that an instruction to switch to the wide-angle lens has not been issued (NO in step S 507 ), the processing proceeds to step S 512 . In step S 512 , the system control unit  50  determines whether an instruction to switch to the telephoto lens has been issued. In a case where it is determined in step S 512  that an instruction to switch to the telephoto lens has been issued (YES in step S 512 ), the processing proceeds to step S 513 . In a case where it is determined that an instruction to switch to the telephoto lens has not been issued (NO in step S 512 ), the processing proceeds to step S 521 . The instruction to switch to the wide-angle lens can be issued by a touch operation on the item  701  displayed on the display unit  28 . For example, if a tap operation of touching the item  701  for a short time is performed once, the wide-angle lens of the lens unit  205  is started up, and if a tap operation is further performed once again, the telephoto lens of the lens unit  203  is started up. 
     In step S 508 , the system control unit  50  starts up the wide-angle lens among lenses of the rear camera on the first surface. That is, the system control unit  50  starts up the camera of the lens unit  205 . 
     In step S 509 , the system control unit  50  sequentially displays, on the display unit  28 , captured images acquired via the lens unit  205  (live view image). 
     In step S 510 , the system control unit  50  displays an image capturing setting available to the wide-angle lens (the lens unit  205 ).  FIG.  7 B  illustrates a display example of the display unit  28  to be displayed when the wide-angle lens is started up among lenses of the rear camera. The item  704  is an item for changing an aperture value, and an item  706  is an item for executing processing of correcting distortion. Distortion sometimes becomes noticeable in an image captured by a wide-angle lens of a rear camera. Thus, by executing image processing of correcting distortion, distortion can be made less noticeable. Aside from these items, the same items as those illustrated in  FIG.  7 A  are also displayed. 
     In step S 511 , the system control unit  50  displays “0.5×” on the display unit  28  as an image capturing magnification. As illustrated in  FIG.  7 B , an item  707  indicates a magnification of current image capturing, and it can be seen that a display magnification is smaller than that of the standard lens (i.e., an image capturing field angle has become wider). In other words, in a case where an image capturing field angle of image capturing performed using the wide-angle lens illustrated in  FIG.  4 A  is 110 degrees, an image capturing magnification is displayed as 0.5× (smaller than 1×). In other words, by displaying “0.5×” as a field angle set when electronic zoom is not performed by the wide-angle lens, the user can recognize that a currently-displayed field angle has become larger than that of the standard lens. 
     In step S 513 , the system control unit  50  starts up the telephoto lens among lenses of the rear camera on the first surface. That is, the system control unit  50  starts up the camera of the lens unit  203 . 
     In step S 514 , the system control unit  50  sequentially displays, on the display unit  28 , captured images acquired via the lens unit  203  (live view image). 
     In step S 515 , the system control unit  50  displays an image capturing setting available to the telephoto lens (the lens unit  203 ).  FIG.  7 C  illustrates a display example of the display unit  28  to be displayed when the telephoto lens is started up among lenses of the rear camera. The item  704  is an item for changing an aperture value. In image capturing executed by the telephoto lens of the rear camera, the items  705  and  706  displayed when other image capturing magnifications are used are not displayed. Aside from these items, the same items as those illustrated in  FIG.  7 A  are also displayed. 
     In step S 516 , the system control unit  50  displays “2.0×” on the display unit  28  as an image capturing magnification. As illustrated in  FIG.  7 C , an item  708  indicates a magnification of current image capturing, and it can be seen that a display magnification is larger than that of the standard lens (i.e., an image capturing field angle has become narrower). In other words, in a case where an image capturing field angle of image capturing performed using the telephoto lens illustrated in  FIG.  4 A  is 30 degrees, an image capturing magnification is displayed as 2.0×. In other words, by displaying “2.0×” as a field angle set when electronic zoom is not performed by the wide-angle lens, the user can recognize that a currently displayed field angle has become smaller than that of the standard lens. 
     In the image capturing performed using the rear camera, a person is often regarded as a subject or a landscape image is often captured, using the standard lens or the wide-angle lens. In addition, an image of a distant subject is captured using the telephoto lens. In addition, three lenses, which are larger in number than the number of lenses of the front camera on the second surface, are provided, and a field angle range in which image capturing can be performed is also large. Thus, when “1.0×” is displayed, it can be recognized that a reference image capturing magnification (i.e., a lens other than a lens on the wide-angle side or the telephoto side) is used, and it can be recognized that there is a lens that can perform image capturing at a field angle wider or more telephoto than the currently used lens. In other words, if “1.0×” is displayed as an image capturing magnification in a state in which three or more lenses are provided, it becomes easier for the user to recognize that a magnification can be changed to a magnification smaller than 1.0× or larger than 1.0×. 
     In step S 517 , the system control unit  50  determines whether an instruction to switch to the standard lens has been issued. Switching from the wide-angle lens to the standard lens can be performed by a touch operation on the item  708 . By touch operations on the items  701 ,  707 , and  708 , image capturing magnifications are selected in order in a toggle manner. In other words, image capturing magnifications are toggled in the order of 1.0×, 0.5×, and 2.0×, but the order is not limited to this order. The items  701 ,  707 , and  708  can be always displayed together with a live view image, and the user may be enabled to select any of these. In a case where it is determined that an instruction to switch to the standard lens has been issued (YES in step S 517 ), the processing proceeds to step S 502 . In a case where it is determined that an instruction to switch to the standard lens has not been issued (NO in step S 517 ), the processing proceeds to step S 518 . 
     In step S 518 , the system control unit  50  determines whether a change operation of an image capturing magnification has been performed. As to a change of an image capturing magnification, after a long-pressing operation of the item  701 , an item  711  illustrated in  FIG.  7 D  is displayed, and an image capturing magnification can be changed by a touch move on a bar of the item  711 . The item  711  indicates settable image capturing magnifications. By moving a touch position, the user can set an image capturing magnification while viewing a live view screen. The item  711  is hidden when the user releases the touch. In a case where it is determined that a change operation of an image capturing magnification has been performed (YES in step S 518 ), the processing proceeds to step S 519 . In a case where it is determined that a change operation of an image capturing magnification has not been performed (NO in step S 518 ), the processing proceeds to step S 521 . 
     In step S 519 , the system control unit  50  acquires an image capturing magnification designated by a touch operation on the item  711 . In step S 520 , the system control unit  50  determines a lens corresponding to the acquired image capturing magnification, from among the telephoto lens, the standard lens, and the wide-angle lens. For example, if a magnification larger than 1.0× and smaller than 2.0× is designated by a touch operation on the item  711 , the standard lens is selected. If a magnification smaller than 1.0× is selected, the wide-angle lens is selected, and if a magnification equal to or larger than 2.0× is selected, the telephoto lens is selected. In a case where it is determined that the standard lens is selected, the processing proceeds to step S 502 . In a case where it is determined that the wide-angle lens is selected, the processing proceeds to step S 508 . In a case where it is determined that the telephoto lens is selected, the processing proceeds to step S 513 . 
     In step S 521 , the system control unit  50  determines whether an image capturing instruction has been issued. The image capturing instruction can be issued by a touch operation on the item  702 . In a case where it is determined that an image capturing instruction has been issued (YES in step S 521 ), the processing proceeds to step S 522 . In a case where it is determined that an image capturing instruction has not been issued (NO in step S 521 ), the processing proceeds to step S 523 . 
     In step S 522 , the system control unit  50  performs image capturing processing. The system control unit  50  records a captured image onto the recording medium  200 . 
     In step S 523 , the system control unit  50  determines whether an instruction to switch to the front camera has been issued. That is, the system control unit  50  determines whether an instruction to switch to the camera on the second surface has been issued. The instruction to switch to the front camera can be issued by a touch operation on the item  703 . In a case where it is determined that an instruction to switch to the front camera has been issued (YES in step S 523 ), the processing proceeds to image capturing control processing of the front camera that is illustrated in  FIG.  6 A . In a case where it is determined that an instruction to switch to the front camera has not been issued (NO in step S 523 ), the processing proceeds to step S 524 . 
     In step S 524 , the system control unit  50  determines whether to end the camera function. An instruction to end the camera function can be issued by pressing the power switch  72 , an operation of scrolling the display unit  28  upward, or a pinch operation of pinching a live view image. In a case where it is determined that an instruction to end the camera function has been has been issued (YES in step S 524 ), the processing illustrated in  FIGS.  5 A and  5 B  ends. In a case where it is determined that an instruction to end the camera function has not been issued (NO in step S 524 ), the processing proceeds to step S 525 . 
     In step S 525 , the system control unit  50  determines whether a currently used lens is the standard lens. In a case where a currently used lens is the standard lens (YES in step S 525 ), the processing proceeds to step S 507 . In a case where a currently used lens is not the standard lens (NO in step S 525 ), the processing proceeds to step S 517 . 
     Next, image capturing control processing of the front camera according to the present exemplary embodiment will be described with reference to  FIGS.  6 A and  6 B . The processing is started if it is determined in step S 523  of  FIG.  5 B  that an instruction to switch to the front camera has been issued (YES in step S 523 ). 
     In step S 601 , the system control unit  50  starts up the wide-angle lens among lenses of the front camera on the second surface. That is, the system control unit  50  starts up the camera of the lens unit  202 . In other words, if an instruction to start up the front camera is issued, a camera on the wide-angle side is initially started up. In a case where an instruction to start up the front camera is issued in this manner, the user who desires to perform image capturing on the wide-angle side needs not to perform an operation of changing a field angle from a field angle of the standard lens to a field angle on the wide-angle side, by starting up a lens on the wide-angle side. The front camera starts up at a wide-angle end, the user can thus recognize a limit at which a field angle cannot be made any wider by an optical requirement. The user can recognize a wide-angle end (i.e., the largest field angle at which image capturing can be performed) when the front camera starts up, the user can therefore easily consider a range in which image capturing can be performed, and consider whether to narrow an image capturing range. 
     In step S 602 , the system control unit  50  sequentially displays, on the display unit  28 , captured images acquired via the lens unit  201  (live view image). 
     In step S 603 , the system control unit  50  displays an image capturing setting available to the wide-angle lens (the lens unit  202 ).  FIG.  7 E  illustrates a display example of the display unit  28  to be displayed when the front camera is started up. The item  704  is an item for changing an aperture value, and the item  705  is an item for changing a beautiful skin effect. When an image including a person is captured by the wide-angle lens of the front camera, there is a possibility that a face appears big. It is therefore desirable that the beautiful skin effect is provided. When the front camera starts up, the photo mode indicated by the item  700  is selected, but the camera may start up in a state in which an image capturing mode set when the user starts up the camera lastly is selected. 
     In step S 604 , the system control unit  50  displays “1.0×” on the display unit  28  as an image capturing magnification. As illustrated in  FIG.  7 E , an item  712  indicates a magnification of current image capturing, and “1.0×” is displayed at the time of start-up. In other words, in a case where an image capturing field angle of image capturing performed using the wide-angle lens illustrated in  FIG.  4 B  is 110 degrees, an image capturing magnification is displayed as 1.0×. In other words, the user can recognize that a field angle becomes further larger if the field angle is changed with respect to a currently displayed field angle, by displaying “1.0×” as a field angle set when electronic zoom is not performed by the wide-angle lens. 
     In step S 605 , the system control unit  50  determines whether an instruction to switch to the standard lens has been issued. In a case where it is determined that an instruction to switch to the standard lens has been issued (YES in step S 605 ), the processing proceeds to step S 607 . In a case where it is determined that an instruction to switch to the standard lens has not been issued (NO in step S 605 ), the processing proceeds to step S 610 . The instruction to switch to the standard lens can be issued by a touch operation on the item  712  displayed on the display unit  28 . For example, if a tap operation of touching the item  712  for a short time is performed once, the standard lens of the lens unit  201  is started up. 
     In step S 606 , the system control unit  50  starts up the standard lens among lenses of the front camera on the second surface. That is, the system control unit  50  starts up the camera of the lens unit  201 . 
     In step S 607 , the system control unit  50  sequentially displays, on the display unit  28 , captured images acquired via the lens unit  201  (live view image). 
     In step S 608 , the system control unit  50  displays an image capturing setting available to the standard lens (the lens unit  201 ).  FIG.  7 F  illustrates a display example of the display unit  28  to be displayed when the front camera is started up among lenses of the front camera. The item  704  is an item for changing an aperture value, and the item  705  is an item for changing a beautiful skin effect. Aside from these items, the same items as those illustrated in  FIG.  7 A  are also displayed. 
     In step S 609 , the system control unit  50  displays “2.0×” on the display unit  28  as an image capturing magnification. As illustrated in  FIG.  7 F , an item  713  indicates a magnification of current image capturing, and it can be seen that a display magnification has become larger than 1.0× (i.e., an image capturing field angle has become narrower). In other words, in a case where an image capturing field angle of image capturing performed using the standard lens illustrated in  FIG.  4 A  is 70 degrees, an image capturing magnification is displayed as 2.0×. In other words, the user can recognize that a currently displayed field angle can be made larger, by displaying “2.0×” as a field angle set when electronic zoom is not performed by the standard lens. If “1.0×” is displayed as an image capturing magnification even when the standard lens is used, it can be recognized that a current field angle can be changed using electronic zoom to a field angle corresponding to a magnification larger than 1.0×, and the field angle can be narrowed, but it is difficult to intuitively recognize whether the field angle can be made larger than the current field angle. In other words, in a case where “1.0×” is displayed as an image capturing magnification, it can be seen that a field angle can be narrowed using electronic zoom, but it is difficult to recognize whether there is a lens that can perform image capturing at a field angle wider than that of a currently used lens. Nevertheless, when the standard lens and the wide-angle lens are provided, the user can recognize that a current field angle is a field angle magnified to 2.0× from a certain field angle, if “2.0×” (magnification larger than 1.0×) is displayed when the standard lens is used. Then, the user can recognize that the current field angle can be changed to an unmagnified field angle. That is, the user can recognize that image capturing at a wider field angle can be performed. On the other hand, when the standard lens and the wide-angle lens are provided, the user can at least recognize that an image capturing magnification can be changed using electronic zoom to an image capturing magnification larger than 1.0×, if “1.0×” is displayed when the wide-angle lens is used. The user can therefore recognize that a current image capturing field angle is a wider field angle within a changeable field angle range, and image capturing can be performed at the image capturing field angle. 
     In step S 610 , the system control unit  50  detects, from a live view image, a size of a face in an image being captured, and the number of faces. 
     In step S 611 , the system control unit  50  determines whether the total area (size) of faces acquired in step S 610  is smaller than a predetermined size, or whether the number of faces is one, or whether none of these conditions is satisfied. In a case where it is determined that either of the conditions is satisfied (YES in step S 611 ), the processing proceeds to step S 606 . In a case where it is determined that none of the conditions is satisfied (NO in step S 611 ), the processing proceeds to step S 613 . If an area of a region in the entire live view image that includes a face is smaller than a predetermined size (area), such as ⅕ or ⅛ of the entire live view image, there is a high possibility that a camera and a subject are separated enough from each other even if image capturing is not performed using the wide-angle lens. Thus, in this case, if image capturing is performed using a standard lens, an image in which the face of the user is in a large size can be captured. On the other hand, if the face of the user is not separated enough, if image capturing is performed using the standard lens, adjusting a field angle in such a manner as not to include a hand holding the smartphone accordingly makes it difficult to perform image capturing from a position sufficiently higher than the face. Consequently, a captured image in which the face of the user appears big is sometimes obtained. If a distance between a camera and a subject is large enough, the user is highly likely to perform image capturing using the standard lens. If the distance is not large enough, the user is highly likely to perform image capturing using the wide-angle lens. By determining the size of a face as in step S 611 , and automatically performing image capturing using the standard lens if the area of the face is small, a possibility that image capturing can be performed at an appropriate field angle without the user switching a lens becomes high. 
     In a case where the number of faces is one, a subject becomes relatively small with respect to a live view image, even if image capturing is performed using the standard lens, there is a low possibility that the face appears big, and therefore automatically switching to the standard lens reduces the operation of the user. 
     In step S 612 , the system control unit  50  determines whether an instruction to switch to the wide-angle lens has been issued. In a case where it is determined that an instruction to switch to the wide-angle lens has been issued (YES in step S 612 ), the processing proceeds to step S 601 . In a case where it is determined that an instruction to switch to the wide-angle lens has not been issued (NO in step S 612 ), the processing proceeds to step S 613 . The instruction to switch to the wide-angle lens can be issued by a touch operation on the item  713  displayed on the display unit  28 . For example, if a tap operation of touching the item  713  is performed once for a short time, the wide-angle lens of the lens unit  202  is started up. 
     In step S 613 , the system control unit  50  determines whether an image capturing instruction has been issued. The image capturing instruction can be issued by a touch operation on the item  702 . In a case where it is determined that an image capturing instruction has been issued (YES in step S 613 ), the processing proceeds to step S 614 . In a case where it is determined that an image capturing instruction has not been issued (NO in step S 613 ), the processing proceeds to step S 615 . 
     In step S 614 , the system control unit  50  performs image capturing processing. The system control unit  50  records a captured image on the recording medium  200 . 
     In step S 615 , the system control unit  50  determines whether a change operation of an image capturing magnification has been performed. As to a change of an image capturing magnification, after a long-pressing operation of the item  712 , an item for changing an image capturing magnification, like the item  711  illustrated in  FIG.  7 D , is displayed, and an image capturing magnification can be changed by a touch move on a bar of the item. In a case where it is determined that a change operation of an image capturing magnification has been performed (YES in step S 615 ), the processing proceeds to step S 616 . In a case where it is determined that a change operation of an image capturing magnification has not been performed (NO in step S 615 ), the processing proceeds to step S 618 . 
     In step S 616 , the system control unit  50  acquires an image capturing magnification designated by a touch operation on the item displayed in step S 615 . In step S 617 , the system control unit  50  determines whether a lens corresponding to the acquired image capturing magnification is the standard lens or the wide-angle lens. For example, if a large magnification equal to or larger than 2.0× is designated by a touch operation on the item displayed in step S 615 , the standard lens is selected. If a magnification smaller than 2.0× is selected, the wide-angle lens is selected. In a case where it is determined that the standard lens is selected, the processing proceeds to step S 606 . In a case where it is determined that the wide-angle lens is selected, the processing proceeds to step S 601 . 
     In step S 618 , the system control unit  50  determines whether a start-up instruction of a phone call function has been issued using the smartphone  100 . The start-up instruction of the phone call function may be made executable when the camera function is being started up, or may be made executable even if the camera function has not been started up. In a case where it is determined that a start-up instruction of the phone call function has been issued (YES in step S 618 ), the processing proceeds to step S 606 . In a case where it is determined that a start-up instruction of the phone call function has not been issued (NO in step S 618 ), the processing proceeds to step S 619 . 
     In step S 619 , the system control unit  50  determines whether an instruction to switch to the rear camera has been issued. That is, the system control unit  50  determines whether an instruction to switch to the camera on the first surface has been issued. The instruction to switch to the rear camera can be issued by a touch operation on the item  703 . In a case where it is determined that an instruction to switch to the rear camera has been issued (YES in step S 619 ), the processing proceeds to step S 502  of  FIG.  5 A . In a case where it is determined that an instruction to switch to the rear camera has not been issued (NO in step S 619 ), the processing proceeds to step S 620 . 
     In step S 620 , the system control unit  50  determines whether to end the camera function. An instruction to end the camera function can be issued by pressing the power switch  72 , an operation of scrolling the display unit  28  upward, or a pinch operation of pinching a live view image. In a case where it is determined that an instruction to end the camera function has been has been issued, the processing illustrated in  FIGS.  6 A and  6 B  ends. In a case where it is determined that an instruction to end the camera function has not been issued, the processing proceeds to step S 621 . 
     In step S 621 , the system control unit  50  determines whether a currently used lens is the standard lens. In a case where the currently used lens is the standard lens, the processing proceeds to step S 612 . In a case where a currently used lens is not the standard lens, the processing proceeds to step S 605 . 
     In the above-described exemplary embodiment, the description has been given of an example in which an item for changing an image capturing magnification is indicated by a number, but the present exemplary embodiment is not limited to this. The display to be described below may be employed.  FIGS.  7 G to  7 K  each illustrate an example of an item for changing an image capturing magnification. In the above-described exemplary embodiment, the description has been given of an example in which the item  711  for changing an image capturing magnification is displayed if the item  701  or the  712  is long-pressed. However, the item may be always displayed together with a live view image even if a display instruction is not issued from the user.  FIG.  7 G  illustrates an item  714  for changing an image capturing magnification to be displayed when the rear camera is started up. A line  714   a  in the item  714  indicates a midmost position between a wide-angle end  714   c  and a telephoto end  714   b.  A designation item  714   d  overlapping the line  714   a  is movable, and an image capturing magnification can be changed by moving the designation item  714   d.  An actual central field angle of a range from a field angle set when the wide-angle end  714   c  is actually selected, to a field angle set when the telephoto end  714   b  is actually selected needs not correspond to an image capturing magnification of 1.0×.  FIG.  7 H  illustrates an item  715  for changing an image capturing magnification that is to be displayed when the rear camera is started up. An item  715   a  in the item  715  indicates that the standard lens is started up. The item  715   a  is surrounded by a bold frame, and indicates that image capturing is currently performed using the standard lens at a field angle set without using electronic zoom. By moving a touch position on the item  715 , an image capturing magnification can be changed. If an item  715   b  is selected, the telephoto lens starts up, and if an item  715   c  is selected, the wide-angle lens starts up. If a position on a bar between items is selected, an image capturing magnification can be changed to an image capturing magnification set using electronic zoom.  FIG.  7 I  illustrates a display mode of the item  714  displayed when an image capturing magnification of the rear camera is changed toward the telephoto side. By moving the designation item  714   d  toward the telephoto side, an image capturing magnification can be changed.  FIG.  7 J  illustrates an item  716  for changing an image capturing magnification that is to be displayed when the front camera is started up. A designation item  716   a  is an item for changing an image capturing magnification. By changing a touch position on the item  716 , an image capturing magnification can be changed. In addition, an item  716   b  indicates a telephoto end, and if the designation item  716   a  is moved up to the item  716   b,  an image capturing magnification can be made large. Because the designation item  716   a  exists at the end on the wide-angle side when the front camera is started up, the user can recognize that a current live view image is captured at a widest angle.  FIG.  7 K  illustrates an item  717  for changing an image capturing magnification that is to be displayed when the front camera is started up. An item  717   a  corresponds to an image capturing magnification set when the wide-angle lens is started up, and an item  717   b  corresponds to an image capturing magnification set when the standard lens is started up. By touching a position on the item  717 , an image capturing magnification can be changed. Because the item  717   a  is selected when the front camera is started up, the user can recognize that a current image capturing magnification is on the wide-angle side. 
     According to the above-described exemplary embodiment, the user can perform image capturing at a wide field angle without increasing the number of operation steps, when performing image capturing using the front camera. 
     The description has been given of an example in which a lens is switched to the standard lens if a phone call starts in step S 618 . Also in the following case, a lens may be switched to the standard lens when the front camera starts up. For example, a scene on the background of a person is determined from a captured image, and in a case where the background is a light-colored wall or a background in a room the user is highly likely to desire to capture an image in which a size of a person is large, and thus a lens is switched to the standard lens. In contrast, in a case where it is determined that a building or a landscape exists the user is highly likely to desire to capture an image including the landscape or the building, and thus the wide-angle lens is started up. 
     Next, image capturing mode selection processing according to the present exemplary embodiment will be described with reference to flowcharts in  FIGS.  8 A,  8 B,  8 C and  9   . The processing is implemented by loading a program recorded on the nonvolatile memory  56 , onto the system memory  52 , and the system control unit  50  executing the program. The processing starts when the power of the smartphone  100  is turned on. The image capturing mode selection processing illustrated in  FIGS.  8 A,  8 B,  8 C and  9    is premised on a case where a rear camera on the first surface includes a super-wide-angle lens, a wide-angle lens, and a standard lens, and a front camera on the second surface includes a wide-angle lens and a standard lens. In other words, the description will be given assuming that the lens units illustrated in  FIGS.  3 A and  3 B  are arranged on a smartphone, but the configuration is not limited to this. In the image capturing control processing described with reference to  FIGS.  5 A,  5 B,  6 A and  6 B , a change of an image capturing magnification in the camera function has been described. In the following flowchart, a change of an image capturing mode in the camera function will be described together with the control of a change of an image capturing magnification. The exemplary embodiment described with reference to  FIGS.  5 A,  5 B,  6 A and  6 B , and the exemplary embodiment to be described with reference to  FIGS.  8 A,  8 B,  8 C and  9    may be executed in combination. 
     In step S 801 , the system control unit  50  determines whether a camera function start-up instruction has been issued. The camera function start-up instruction can be issued by touching an item of a camera that is displayed on the display unit  28 . In a case where it is determined that a camera function start-up instruction has been issued (YES in step S 801 ), the processing proceeds to step S 802 . In a case where it is determined that a camera function start-up instruction has not been issued (NO in step S 801 ), the processing proceeds to step S 803 . 
     In step S 802 , the system control unit  50  starts up the standard lens among lenses of the rear camera on the first surface. That is, the system control unit  50  starts up the camera of the lens unit  203 . In other words, if the camera function is started up, the rear camera starts up. As described below, the rear camera can be switched to a camera on the second surface (i.e., front camera) after the rear camera starts up. 
     In step S 803 , the system control unit  50  performs other processing. Examples of the other processing include reproduction of images acquired via the lens units  201  to  205 , browsing on the Internet, and editing of images. 
     In step S 804 , the system control unit  50  sequentially displays, on the display unit  28 , captured images acquired via the lens unit  203  (live view image). 
     In step S 805 , the system control unit  50  displays candidates of selectable image capturing modes on the display unit  28 . Candidates of image capturing modes include a photo mode, a night mode, an automatic determination mode, a portrait mode, a panorama mode, a video mode, a time-lapse mode, and a manual mode.  FIGS.  10 A to  10 E and  11 A to  11 D  each illustrate an example of display to be described with reference to the flowcharts in  FIGS.  8 A,  8 B,  8 C and  9   .  FIG.  10 A  illustrates an example of an image capturing screen to be displayed on the display unit  28  when the rear camera is started up. An item group  1016  includes items  1004  to  1011  corresponding to image capturing modes, and a part of the items are displayed on the display unit  28 . In  FIG.  10 A , the items  1004  to  1006 , and  1009 , and a part of the items  1007  and  1010  are displayed. The item  1004  indicates the photo mode, the item  1005  indicates the video mode, the item  1006  indicates the panorama mode, the item  1007  indicates the portrait mode, the item  1008  indicates the manual mode (M mode), and the item  1009  indicates the night mode. Furthermore, the item  1010  indicates the time-lapse mode and the item  1011  indicates the automatic determination mode (AI mode). In  FIGS.  10 A to  10 D, and  11 B , items corresponding to the image capturing mode not actually displayed are also displayed for the sake of explanatory convenience. When the camera function starts up, the photo mode is selected as an image capturing mode, and the corresponding item  1004  is displayed in a state of being in contact with a mark  1014  indicating that the item is selected. An image capturing mode corresponding to an item displayed immediately below the mark  1014  is a currently selected image capturing mode. The mark  1014  is displayed at the center in a short direction of the display unit  28 , and even if a selected image capturing mode is changed, the position remains unchanged. Thus, if a selected image capturing mode is changed by scrolling the item group  1016 , among the image capturing modes included in the item group  1016 , image capturing modes displayed on the display unit  28  change. An item  1001  indicates 1.0× as a current image capturing magnification, and is surrounded by a line thicker than those surrounding an item  1002  (0.5×) and an item  1003  (0.3×) that indicate other image capturing magnifications. By changing a display mode in this manner, the user can recognize a currently selected image capturing magnification. If an item  1013  is selected, a lens can be switched to a lens of the front camera arranged on the second surface. An item  1012  is an item for issuing an image capturing instruction. 
     In step S 806 , the system control unit  50  determines whether an instruction to switch to the wide-angle lens has been issued. In a case where it is determined that an instruction to switch to the wide-angle lens has been issued, the processing proceeds to step S 807 . In a case where it is determined that an instruction to switch to the wide-angle lens has not been issued, the processing proceeds to step S 811 . In step S 811 , the system control unit  50  determines whether an instruction to switch to the super-wide-angle lens has been issued. In a case where it is determined in step S 811  that an instruction to switch to the super-wide-angle lens has been issued, the processing proceeds to step S 812 . In a case where it is determined that an instruction to switch to the super-wide-angle lens has not been issued, the processing proceeds to step S 816 . The instruction to switch to the wide-angle lens can be issued by a touch operation on the item  1002  displayed on the display unit  28 . The instruction to switch to the super-wide-angle lens can be issued by a touch operation on the item  1003  displayed on the display unit  28 . 
     In step S 807 , the system control unit  50  starts up the wide-angle lens among lenses of the rear camera on the first surface. That is, the system control unit  50  starts up the camera of the lens unit  204 . 
     In step S 808 , the system control unit  50  sequentially displays, on the display unit  28 , captured images acquired via the lens unit  204  (live view image). 
     In step S 809 , the system control unit  50  determines whether a current image capturing mode is the photo mode. In a case where it is determined that a current image capturing mode is the photo mode (YES in step S 809 ), the processing proceeds to step S 810 . In a case where it is determined that a current image capturing mode is not the photo mode (NO in step S 809 ), the processing proceeds to step S 824 . 
     In step S 810 , the system control unit  50  highlights an image capturing mode suitable for image capturing performed using a wide-angle camera, and displays an unsuitable image capturing mode in a grayout state.  FIG.  10 B  illustrates a display example of the display unit  28  to be displayed in a case where a lens is switched to the wide-angle lens in the photo mode. As illustrated in  FIG.  10 B , an item  1009   a  indicating the night mode and an item  1005   a  indicating the video mode are displayed in such a manner as to be distinguishable from the other items (i.e.,  1006 ,  1010 ). For example, displaying an item in a distinguishable manner refers to painting the item in eye-catching color, displaying the item in a large size than those of other items, or displaying the item in a state of vibrating slightly. In addition, an item  1007   a  indicating the portrait mode is displayed in a grayout state. The grayout state indicates that image capturing in the portrait mode is not to be performed when the wide-angle lens is selected. A display mode of the item  1007   a  needs not be the grayout state, and the item itself may be displayed in faint color or displayed in a small size. The item  1007   a  may be hidden. In other words, in a case where the wide-angle lens is selected in the photo mode, the user is highly likely to earnestly desire to perform image capturing using the wide-angle lens. Thus, by presenting an image capturing mode suitable for image capturing performed using the wide-angle lens, to the user in an easy-to-understand manner, the user can swiftly switch an image capturing mode. In addition, by displaying, in the grayout state, an image capturing mode that disables image capturing performed using the wide-angle lens, the user can recognize that, if the image capturing mode in the grayout state is selected, image capturing performed using the wide-angle lens becomes inexecutable. If the video mode is selected when the wide-angle lens is used, a time series variation in a wide range can be recorded. If the night mode is selected when the wide-angle lens is used, it is possible to capture an image including a plurality of buildings, or including a large building. The image capturing modes suitable for the wide-angle lens are not limited to the above-described image capturing modes. 
     In step S 812 , the system control unit  50  starts up the super-wide-angle lens among lenses of the rear camera on the first surface. That is, the system control unit  50  starts up the camera of the lens unit  205 . 
     In step S 813 , the system control unit  50  sequentially displays, on the display unit  28 , captured images acquired via the lens unit  205  (live view image). 
     In step S 814 , the system control unit  50  determines whether a current image capturing mode is the photo mode. In a case where it is determined that a current image capturing mode is the photo mode (YES in step S 814 ), the processing proceeds to step S 815 . In a case where it is determined that a current image capturing mode is not the photo mode (NO in step S 814 ), the processing proceeds to step S 824 . 
     In step S 815 , the system control unit  50  highlights an image capturing mode suitable for image capturing performed using the super-wide-angle camera, and displays an unsuitable image capturing mode in the grayout state.  FIG.  10 C  illustrates a display example of the display unit  28  to be displayed in a case where a lens is switched to the super-wide-angle lens in the photo mode. As illustrated in  FIG.  10 C , the item  1009   a  indicating the night mode and an item  1015  indicating a distortion correction mode are displayed in such a manner as to be distinguishable from the other items (i.e.,  1005 ,  1010 ). In addition, the item  1007   a  indicating the portrait mode and an item  1006   a  indicating the panorama mode are displayed in the grayout state. The grayout state indicates that image capturing in the portrait mode or the panorama mode is not to be performed when the super-wide-angle lens is selected. In other words, in a case where the super-wide-angle lens is selected in the photo mode, the user is highly likely to earnestly desire to perform image capturing using the super-wide-angle lens. Thus, by presenting an image capturing mode suitable for image capturing performed using the super-wide-angle lens, to the user in an easy-to-understand manner, the user can swiftly switch an image capturing mode. In addition, by displaying, in the grayout state, image capturing modes that disable image capturing performed using the super-wide-angle lens, the user can recognize that, if the image capturing modes in the grayout state are selected, image capturing performed using the super-wide-angle lens becomes inexecutable. In the image capturing performed using the super-wide-angle lens, distortion can occur in the vicinity of the end of an image, and therefore image capturing in the distortion correction mode is executable. Thus, when the super-wide-angle lens is used, it is desirable to make the user easily recognize that image capturing in the distortion correction mode is executable and recommended. In addition, in the panorama mode, image composition might become inexecutable due to the occurrence of distortion in the vicinity of the end of an image, and therefore image capturing is not to be performed. In step S 816 , the system control unit  50  determines whether a current lens is the standard lens. In a case where it is determined that a currently used lens is the standard lens (YES in step S 816 ), the processing proceeds to step S 824 . In step S 824 , the system control unit  50  performs processing of switching an image capturing mode that is to be performed in a case where all image capturing modes are selectable. In a case where it is determined that a currently used lens is not the standard lens (NO in step S 816 ), the processing proceeds to step S 817 . In step S 817 , the system control unit  50  performs processing of switching an image capturing mode that is to be performed in a case where a part of image capturing modes are unselectable. 
     In step S 817 , the system control unit  50  determines whether the user has issued an instruction to scroll the item group  1016  indicating image capturing modes. In a case where it is determined that the user has issued an instruction to scroll the item group  1016  indicating image capturing modes (YES in step S 817 ), the processing proceeds to step S 818 . In a case where it is determined that the user has not issued an instruction to scroll the item group  1016  indicating image capturing modes (NO in step S 818 ), the processing proceeds to step S 819 . 
     In step S 818 , the system control unit  50  changes an image capturing mode to a selectable image capturing mode existing at a position closest to the currently selected image capturing mode, among image capturing modes existing in a scroll direction.  FIG.  11 A  is a diagram illustrating selection of an image capturing mode that is to be made in a case where the wide-angle lens is selected. As illustrated in ( 2 ) in  FIG.  11 A , if a currently selected image capturing mode is the video mode, when the item group  1016  is scrolled by a distance L in a left direction extending along the short direction of the display unit  28 , the item  1006  (panorama mode) existing in the right direction when viewed from the item  1005 , and being selectable is selected. As illustrated in ( 1 ) in  FIG.  11 A , if a currently selected image capturing mode is the photo mode, the item  1005  is selected in accordance with the item group  1016  being scrolled in the left direction by a distance Ls smaller than the distance L. The item  1005  corresponds to the video mode. By a scroll amount smaller than a normal amount, the photo mode can be switched to the video mode being an image capturing mode recommended for image capturing performed using the wide-angle lens. As illustrated in ( 3 ), in a case where the panorama mode is selected, if the user issues an instruction to scroll the item group  1016  in the left direction, the neighboring portrait mode is normally selected, but if the panorama mode switches to the portrait mode, image capturing performed using the wide-angle lens becomes inexecutable. Thus, even if the item group  1016  is scrolled in the left direction by the distance L, the item  1007  indicating the portrait mode in the grayout state is not selected (skipped). Then, the item  1008  indicating the manual mode being a selectable image capturing mode existing at a closest position in the left direction when viewed from the item  1006  is selected. 
     In step S 819 , the system control unit  50  determines whether any of the items indicating the image capturing modes has been touch-selected. In other words, the system control unit  50  determines whether an operation (tap operation) of touching any of the items  1004  to  1011 , and detaching the touch without moving a touch position, within a predetermined time being a short time, such as 0.5 seconds or 0.2 seconds, has been performed. In a case where it is determined that an item indicating an image capturing mode has been touch-selected (YES in step S 819 ), the processing proceeds to step S 820  because an image capturing mode is switched even in a case where image capturing performed using the selected lens is inexecutable. In step S 820 , a touched image capturing mode is selected. In  FIG.  11 A , ( 5 ) illustrates a state in which the user performs a tap operation on the item  1007   a  corresponding to the portrait mode. When the wide-angle lens is selected, image capturing in the portrait mode is inexecutable, but if the item  1007   a  is tapped, a state in which the item  1007   a  is selected as illustrated in ( 6 ) can be caused. That is, the image capturing mode can be switched to the portrait mode.  FIG.  11 B  illustrates a display example of the display unit  28  to be displayed after the portrait mode is selected. As illustrated in  FIG.  11 B , it can be seen that an image capturing magnification indicated by the item  1001  is 1.0×, and the wide-angle lens has been switched to the standard lens. 
     In step S 821 , the system control unit  50  determines whether the image capturing mode selected by the operation in step S 819  is an image capturing mode for image capturing executable only by the standard lens. That is, the system control unit  50  determines whether the image capturing mode is an image capturing mode for image capturing inexecutable by the wide-angle lens and the super-wide-angle lens, like the portrait mode. If the image capturing mode is an image capturing mode for image capturing executable only by the standard lens (YES in step S 821 ), the processing proceeds to step S 802 . In step S 802 , the system control unit  50  performs processing of switching to the standard lens. If the image capturing mode is not an image capturing mode for image capturing executable only by the standard lens (NO in step S 821 ), the processing proceeds to step S 822 . 
     In step S 822 , the system control unit  50  determines whether the image capturing mode selected by the operation in step S 819  is an image capturing mode for image capturing executable by the wide-angle lens. That is, the system control unit  50  determines whether the image capturing mode is an image capturing mode for image capturing executable by the standard lens and the wide-angle lens, but inexecutable only by the super-wide-angle lens, like the panorama mode. Even in a case where the image capturing mode is an image capturing mode for image capturing inexecutable by the super-wide-angle lens, if the super-wide-angle lens is switched to the standard lens, a change in field angle becomes large. Thus, it is determined whether image capturing performed using the wide-angle lens is executable, and if image capturing performed using the wide-angle lens is executable (YES in step S 822 ), the processing proceeds to step S 807 . In step S 807 , the super-wide-angle lens is switched to the wide-angle lens. With this configuration, it becomes possible to execute image capturing in an image capturing mode selected by the user, while preventing a change in field angle from getting larger. In a case where the image capturing mode is not an image capturing mode for image capturing executable by the wide-angle lens (NO in step S 822 ), the processing proceeds to step S 823 . 
     In step S 823 , the system control unit  50  displays lenses selectable in the selected image capturing mode, in a distinguishable manner.  FIG.  10 D  illustrates a display example to be displayed in a case where the panorama mode is selected, an item  1003   a  indicating the super-wide-angle lens is displayed in the grayout state, and the item  1002  indicating the wide-angle lens and the item  1001  indicating the standard lens are displayed without being grayed out. The user can thereby recognize that the super-wide-angle lens is unselectable in the panorama mode. 
     In step S 824 , the system control unit  50  performs processing similar to the processing in step S 817 . 
     In step S 825 , the system control unit  50  selects a neighboring item in the scroll direction when being viewed from the item corresponding to the selected image capturing mode, each time a scroll instruction is issued. In step S 818 , an image capturing mode selectable when a scroll operation is performed is selected, and an unselectable image capturing mode is skipped without being selected. In contrast, in step S 825 , a neighboring image capturing mode is selected each time scroll is performed by the distance L.  FIG.  11 A  is a diagram illustrating switching of an image capturing mode that is performed in a case where scroll is performed by the distance L. In ( 1 ) to ( 4 ), each time the user scrolls the item group  1016  in the left direction by the distance L, an item corresponding to an image capturing mode existing immediately below the mark  1014  switches to an item on the right side one by one. Because a display position of the mark  1014  on the display unit  28  remains unchanged, items displayed in a display unit are items corresponding to modes from the time-lapse mode to the portrait mode in ( 1 ), and the items change to items corresponding to modes from the video mode to the manual mode in ( 6 ). 
     The processing in steps S 824  to S 827  is processing to be executed in a case where a selected lens is the standard lens, or in a case where a lens is switched to the wide-angle lens or the super-wide-angle lens in a mode other than the photo mode. In other words, if a selected lens is the standard lens, all image capturing modes are selectable, and thus there is no need to make a specific image capturing mode difficult to be selected. In addition, if the user has not switched the lens to the wide-angle lens or the super-wide-angle lens from the standard lens selected at the time of start-up, the user is highly likely to intend to select a lens after selecting an image capturing mode. Thus, all image capturing modes are displayed in a parallel relationship (a partial image capturing mode is not highlighted or displayed in the grayout state). Furthermore, a partial image capturing mode is not made difficult to be selected. With this configuration, the user who desires to select a lens after selecting an image capturing mode can select an image capturing mode and a lens with good operability. 
     In step S 828 , the system control unit  50  determines whether an image capturing instruction has been issued. The image capturing instruction can be issued by a touch operation on the item  1012 . In a case where it is determined that an image capturing instruction has been issued (YES in step S 828 ), the processing proceeds to step S 829 . In a case where it is determined that an image capturing instruction has not been issued (NO in step S 828 ), the processing proceeds to step S 830 . 
     In step S 829 , the system control unit  50  performs image capturing processing. The system control unit  50  records a captured image onto the recording medium  200 . 
     In step S 830 , the system control unit  50  determines whether an instruction to switch to the front camera has been issued. The instruction to switch to the front camera (i.e., second surface) can be issued by a touch operation on the item  1013 . In a case where it is determined that an instruction to switch to the front camera has been issued (YES in step S 830 ), the processing proceeds to the image capturing mode selection processing of the front camera that is illustrated in  FIG.  9   . In a case where it is determined that an instruction to switch to the front camera has not been issued (NO in step S 830 ), the processing proceeds to step S 831 . 
     In step S 831 , the system control unit  50  determines whether to end the camera function. An instruction to end the camera function can be issued by pressing the power switch  72 , an operation of scrolling the display unit  28  upward, or a pinch operation of pinching a live view image. In a case where it is determined that an instruction to end the camera function has been has been issued (YES in step S 831 ), the processing illustrated in  FIGS.  8 A to  8 C  ends. In a case where it is determined that an instruction to end the camera function has not been issued (NO in step S 831 ), the processing proceeds to step S 832 . 
     In step S 832 , the system control unit  50  determines whether an instruction to switch the rear camera to the standard lens has been issued. The instruction to switch to the standard lens can be issued by a touch operation on the item  1001 . In a case where it is determined that an instruction to switch to the standard lens has been issued (YES in step S 832 ), the processing proceeds to step S 802 . In a case where it is determined that an instruction to switch to the standard lens has not been issued (NO in step S 832 ), the processing proceeds to step S 833 . 
     In step S 833 , the system control unit  50  determines whether a currently selected lens is the standard lens. In a case where it is determined that a currently selected lens is the standard lens (YES in step S 833 ), the processing proceeds to step S 806 . In a case where it is determined that a currently selected lens is not the standard lens (NO in step S 833 ), the processing proceeds to step S 817 . 
     Next, the image capturing mode selection processing of the front camera according to the present exemplary embodiment will be described with reference to the flowchart in  FIG.  9   . The processing is implemented by loading a program recorded on the nonvolatile memory  56 , onto the system memory  52 , and the system control unit  50  executing the program. The processing starts when it is determined in step S 830  of  FIG.  8 C  that an instruction to switch to the front camera has been issued (YES in step S 830 ). 
     In step S 901 , the system control unit  50  starts up the standard lens of the front camera. In other words, the system control unit  50  starts up the standard lens among lenses of the front camera on the second surface. That is, the system control unit  50  starts up the camera of the lens unit  201 . 
     In step S 902 , the system control unit  50  sequentially displays, on the display unit  28 , captured images acquired via the lens unit  201  (live view image). 
     In step S 903 , the system control unit  50  displays, on the display unit  28 , an item group  1017  including the photo mode, the video mode, and the portrait mode.  FIG.  11 C  illustrates an example of a display example to be displayed in a case where the standard lens is started up. When the front camera is started up, the user is highly likely to perform image capturing while regarding himself/herself as a subject, and thus the number of selectable image capturing modes is limited as compared with a case where the rear camera is selected. 
     In step S 904 , the system control unit  50  determines whether an instruction to switch the lens of the front camera to the wide-angle lens has been issued. The instruction to switch to the wide-angle lens can be issued by a touch operation on an item  1019 . In a case where it is determined that an instruction to switch to the wide-angle lens has been issued (YES in step S 904 ), the processing proceeds to step S 905 . In a case where it is determined that an instruction to switch to the wide-angle lens has not been issued (NO in step S 904 ), the processing proceeds to step S 907 . 
     In step S 905 , the system control unit  50  starts up the wide-angle lens of the front camera. In other words, the system control unit  50  starts up the wide-angle lens among lenses of the front camera on the second surface. That is, the system control unit  50  starts up the camera of the lens unit  202 . 
     In step S 906 , the system control unit  50  sequentially displays, on the display unit  28 , captured images acquired via the lens unit  202  (live view image).  FIG.  11 D  illustrates a display example of the display unit  28  to be displayed when the wide-angle lens of the front camera is started up. In the case of the front camera, the standard lens and the wide-angle lens are provided, and image capturing modes for image capturing executable by the standard lens and image capturing modes for image capturing executable by the wide-angle lens are the same. In the case of the front camera, a range of a changeable field angle is not as large as that of the rear camera, and thus selectable image capturing modes are the same as well. Thus, there is no need to make a partial image capturing mode easily-selectable, or make a partial image capturing mode difficult to be selected. 
     In step S 907 , the system control unit  50  determines whether an instruction to switch the lens of the front camera to the standard lens has been issued. The instruction to switch to the standard lens can be issued by a touch operation on an item  1018 . In a case where it is determined that an instruction to switch to the wide-angle lens has been issued (YES in step S 907 ), the processing proceeds to step S 901 . In a case where it is determined that an instruction to switch to the wide-angle lens has not been issued (NO in step S 907 ), the processing proceeds to step S 908 . 
     In step S 908 , the system control unit  50  determines whether an image capturing instruction has been issued. The image capturing instruction can be issued by a touch operation on the item  1012 . In a case where it is determined that an image capturing instruction has been issued (YES in step S 908 ), the processing proceeds to step S 909 . In a case where it is determined that an image capturing instruction has not been issued (NO in step S 908 ), the processing proceeds to step S 910 . 
     In step S 909 , the system control unit  50  performs image capturing processing. The system control unit  50  records a captured image on the recording medium  200 . 
     In step S 910 , the system control unit  50  determines whether an instruction to switch to the rear camera has been issued. The instruction to switch to the rear camera (i.e., lens on the first surface) can be issued by a touch operation on the item  1013 . In a case where it is determined that an instruction to switch to the rear camera has been issued (YES in step S 910 ), the processing proceeds to step S 802 . In step S 802 , the system control unit  50  starts up the standard lens of the rear camera. In a case where it is determined that an instruction to switch to the rear camera has not been issued (NO in step S 910 ), the processing proceeds to step S 911 . 
     In step S 911 , the system control unit  50  determines whether to end the camera function. An instruction to end the camera function can be issued by pressing the power switch  72 , an operation of scrolling the display unit  28  upward, or a pinch operation of pinching a live view image. In a case where it is determined that an instruction to end the camera function has been issued (YES in step S 911 ), the processing illustrated in  FIG.  9    ends. In a case where it is determined that an instruction to end the camera function has not been issued (NO in step S 911 ), the processing proceeds to step S 912 . 
     The processing in steps S 912  to S 915  is processing similar to the processing in steps S 824  to S 827  of  FIG.  8 B . Nevertheless, if the processing in step S 913  or S 915  ends, the processing proceeds to step S 908 . 
     In step S 916 , the system control unit  50  determines whether a currently selected lens is the standard lens. In a case where it is determined that the currently selected lens is the standard lens (YES in step S 916 ), the processing proceeds to step S 904 . In a case where it is determined that the currently selected lens is not the standard lens (NO in step S 916 ), the processing proceeds to step S 907 . 
     According to the above-described exemplary embodiment, it becomes easier for the user to recognize an image capturing mode for image capturing executable when a selected lens is used. In other words, because a recommended image capturing mode and an unrecommended image capturing mode, which is a mode where a lens switches if being selected, for a lens selected in the photo mode are displayed in a distinguishable manner, the user can swiftly recognize an image capturing mode recommended to be selected in a selected field angle. By avoiding hiding an unrecommended image capturing mode, the user can swiftly perform selection without performing a switch operation of a lens, in a case where the user considers in midstream to desire to prioritize the feature of an image capturing mode over a field angle in image capturing. 
     In the above-described exemplary embodiment, the description has been given of an example in which, in a case where an image capturing mode switches to an image capturing mode for image capturing inexecutable by a lens selected in the photo mode, a lens that executes image capturing is switched to a lens that can execute image capturing. Nevertheless, in a case where the user has switched a lens in the photo mode, the user is highly likely to earnestly desire to perform image capturing at a field angle selected by the user, and thus a selected image capturing mode may be selected without changing the field angle. Nevertheless, if the wide-angle lens is used, a blurring effect of a background might become less recognizable, for example, in the portrait mode, and thus the user is notified that the background is not blurred unless the lens is switched to the standard lens. 
     In a case where the user sets the number of pixels to a high value in the camera function, in some cases, image capturing is performed using the wide-angle lens, and image capturing performed using the standard lens becomes inexecutable. In a case where the user sets, on a menu screen or a setting screen of the camera function, the number of pixels to a value equal to or larger than a predetermined value (i.e., sets the number of pixels to a value equal to or larger than the number of pixels at which image capturing is inexecutable unless the wide-angle lens is used), the following operation is performed. More specifically, an image capturing mode for image capturing executable by the wide-angle lens or the super-wide-angle lens among lenses of the rear camera is highlighted, and an image capturing mode for image capturing inexecutable by the wide-angle lens or the super-wide-angle lens is displayed in the grayout state. The user is also notified that, in a case where the user tries to select, by a tap operation, the image capturing mode displayed in the grayout state, a lens switches and the number of pixels further decreases. In a case where the user switches an image capturing mode after checking the notification, image capturing is performed after decreasing the number of pixels and switching the lens to the standard lens. It may be only required that a recommended partial image capturing mode is highlighted without graying out an unrecommended image capturing mode. In contrast, an unrecommended partial image capturing mode may be grayed out, and a recommended image capturing mode may be highlighted. In addition, when a newly-selected lens is used, a display mode of an unrecommended or recommended image capturing mode is changed to the grayout state or a highlighted state in accordance with the lens being selected. 
     When an image capturing mode is switched to an image capturing mode for image capturing inexecutable by the wide-angle lens even if the user who has selected the wide-angle lens does not intend to switch the lens to the standard lens, it is possible to prevent a field angle of a live view image from changing. In other words, it is possible to enhance the visibility for the user by preventing a field angle of a live view image from changing to a field angle of the standard lens or returning to a field angle of the wide-angle lens without the intention of the user in accordance with a change of an image capturing mode, when the user is still selecting an image capturing mode. 
     To indicate a selected image capturing mode, a display mode of an item corresponding to the selected image capturing mode among items in the item group  1016  may be changed. For example, a size of the item may be increased, the color of a character may be changed, or the color of the item may be changed. An item corresponding to a selected image capturing mode, an item corresponding to an unrecommended image capturing mode, and an item corresponding to a recommended image capturing mode are displayed in different display modes. All of these items are displayed in display modes different from a display mode of an image capturing mode that is not selected, and is neither recommended nor unrecommended. In other words, in accordance with a lens being selected, a display mode of an item corresponding to an image capturing mode for image capturing inexecutable by the selected lens is changed to a display mode less noticeable than other unselected items. Alternatively, a display mode of an item corresponding to an image capturing mode recommended for the selected lens is changed to a display mode more noticeable than other unselected items. 
     In the camera function, the user is sometimes enabled to set whether to store an image capturing setting set when the camera function is started up lastly. At this time, in a case where the user prefers to store the lastly-used image capturing setting, the user is highly likely to earnestly desire that an image capturing setting that has been once set is not to be changed. Thus, image capturing modes are displayed based on a lens selected in the photo mode. In other words, a recommended image capturing mode and an unrecommended image capturing mode for the lens selected in the photo mode are made recognizable. In contrast, the user who prefers not to store the lastly-used image capturing setting is highly likely to earnestly desire to prioritize a latest setting. Thus, even if a lens has already been switched, the user is highly likely to desire to prioritize image capturing in an image capturing mode currently selected over the type of a set lens, and therefore a recommended image capturing mode and an unrecommended image capturing mode are not displayed in a recognizable manner in accordance with the lens. 
     The focal lengths and measures of image capturing field angles of the standard lens, the wide-angle lens, and the super-wide-angle lens of the rear camera and the front camera, which have been described above with reference to  FIGS.  3 A,  3 B,  4 A and  4 B , are examples, and are not limited to these. The description has been given of an example in which three types of lenses are arranged on the rear camera and two types of lenses are arranged on the front camera, but the numbers of types are not limited to these, and may be three types or one type may be arranged. 
     The above-described various types of control described to be performed by the system control unit  50  may be performed by one piece of hardware, or the entire apparatus may be controlled by a plurality of pieces of hardware (e.g., central processing units (CPUs), micro processing units (MPUs), and dedicated circuits) sharing the processing. 
     The preferred exemplary embodiments of the present invention have been described in detail, but the present invention is not limited to these specific exemplary embodiments, and various configurations are also included in the present invention without departing from the spirit of the invention. Furthermore, each of the above-described exemplary embodiments merely indicates an exemplary embodiment of the present invention, and the exemplary embodiments can be appropriately combined. 
     In the above-described exemplary embodiment, an example case where the present invention is applied to a smartphone has been described. An application example of the present invention is not limited to this example, and the present invention can be applied to any electronic device as long as the electronic device performs image capturing while switching between a plurality of lenses having different focal lengths. More specifically, the present invention can be applied to a digital camera, a portable image viewer, a printer apparatus including a viewfinder, a digital photo frame, a music player, a game machine, and an electronic book reader. 
     Other Exemplary Embodiment 
     An exemplary embodiment of the present invention is also implemented by executing the following processing. More specifically, the processing is processing of supplying software (program) implementing the functions of the above-described exemplary embodiment, to a system or an apparatus via a network or various recording media, and a computer (or CPU, MPU, etc.) of the system or the apparatus reading a program code and executing the program code. In this case, the program and a nonvolatile storage medium storing the program are included in the present invention. 
     The present invention is not limited to the above exemplary embodiments and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, to apprise the public of the scope of the present invention, the following claims are appended. 
     According to the present invention, it becomes possible to set a field angle with good operability in a case where a photographer itself serves as a subject. 
     Other Embodiments 
     Embodiment(s) of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like. 
     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.