Lens apparatus, imaging apparatus, control method for lens apparatus, control method for imaging apparatus, and program

Abstract

To provide a lens device that can display information on depth of field on a display of a camera main body to improve operability for a user.SOLUTION: A lens device (100) is removably attached to an imaging apparatus (200), and has imaging optical systems (101-105), and a communication unit (111) that can communicate with the imaging apparatus. The communication unit transmits, to the imaging apparatus, first information for calculating depth of field and second information for normalizing the depth of field into a display format of a display (204) of the imaging apparatus.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a lens device and an imaging device capable of adjusting focus by driving a focus lens. [Background technology]

[0002] Imaging devices such as digital still cameras and digital video cameras are capable of adjusting the focus on a subject by driving a focus lens. Patent Document 1 discloses a method for displaying subject distance information that displays the subject distance calculated from the position of the focus lens and optical information of the photographing optical system, together with the depth of field calculated from permissible circle of confusion information. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-45350 A Summary of the Invention [Problem to be solved by the invention]

[0004] The method disclosed in Patent Document 1 can display the depth of field on the display of an interchangeable lens, but cannot display it on the display of the camera body (electronic viewfinder or rear LCD). This requires the user to check the depth of field displayed on the display of the interchangeable lens after taking their eyes off the display of the camera body, which reduces operability.

[0005] Therefore, an object of the present invention is to provide a lens device, an imaging device, a control method for a lens device, a control method for an imaging device, and a program that are capable of displaying information regarding depth of field on a display unit of the camera body to improve user operability. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a lens device that can be attached to an imaging device having a display unit, the lens device including an imaging optical system and a communication unit that can communicate with the imaging device, the communication unit including: lens information obtained by normalizing information about the imaging optical system to a display format of the display unit; Transmitting to the imaging device first information for the imaging device to calculate a depth of field and second information for the imaging device to normalize the depth of field to a display format of the display unit The display unit displays the lens information and information about the depth of field normalized based on the second information. do.

[0007] Other objects and features of the present invention are illustrated in the following examples. Effect of the Invention

[0008] According to the present invention, it is possible to provide a lens device, an imaging device, a control method for a lens device, a control method for an imaging device, and a program that are capable of displaying information regarding depth of field on a display unit of a camera body to improve user operability. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a block diagram of an imaging device in each embodiment. [Diagram 2] FIG. 11 is a diagram showing electronic cam data for each subject distance in each embodiment. [Diagram 3] FIG. 11 is a diagram showing a distance display bar in each embodiment. [Figure 4] FIG. 4 is a diagram showing a distance display bar displayed on a display unit of the camera body. [Diagram 5] FIG. 13 is a diagram showing a case where the display position of the distance display bar is specified in pixel units. [Figure 6] FIG. 11 is a diagram showing an example in which the distance display bar in the first embodiment is divided into 100 parts. [Figure 7] 4 is an approximation formula for calculating a depth of field in the first embodiment. [Figure 8] 11 is a flowchart showing a display process of the depth of field in the first embodiment. [Figure 9] FIG. 13 is a diagram showing an example in which the depth of field is displayed superimposed on the distance display bar in the first embodiment. [Figure 10] FIG. 11 is a diagram showing an example in which a part of a distance display bar is displayed in an enlarged manner in the second embodiment. [Figure 11] FIG. 11 is a diagram showing an example in which a part of a distance display bar is displayed in an enlarged manner in the second embodiment. [Figure 12] FIG. 11 is a diagram showing an example in which the distance display bar in the second embodiment is enlarged and divided into 100 parts. [Figure 13] 13 is a flowchart showing a process for enlarging and displaying a distance display bar in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0011] First, the configuration of the imaging device in each embodiment will be described. Fig. 1 is a block diagram of an imaging device 10. The imaging device 10 is configured with a camera body (imaging device body) 200 and an interchangeable lens (lens device) 100 that can be attached to the camera body 200.

[0012] The interchangeable lens 100 is mechanically and electrically connected to the camera body 200 via a mount (not shown). The interchangeable lens 100 receives power from the camera body 200 via a power supply terminal (not shown) provided on the mount described above. The interchangeable lens 100 then uses the power received from the camera body 200 to operate various actuators (described below) and a lens microcomputer 111. The camera body 200 communicates with the interchangeable lens 100 via a communication terminal unit (not shown) provided on the mount described above, and controls the interchangeable lens 100 by sending control commands to the interchangeable lens 100.

[0013] The camera body 200 has an image sensor 201 including a phase difference AF sensor etc., a signal processing circuit 202, a recording processing unit 203, a display unit 204, an operation unit 205, and a camera microcomputer 206. The image sensor 201 has a CMOS sensor or a CCD sensor, and performs photoelectric conversion on a subject image (optical image) formed by an imaging optical system in the interchangeable lens 100, and outputs an electrical signal (analog signal). The analog signal output from the image sensor 201 is converted into a digital signal by an A / D conversion circuit (not shown).

[0014] The signal processing circuit 202 performs various image processing on the digital signal from the A / D conversion circuit to generate a video signal. The signal processing circuit 202 also generates, from the video signal, focus information indicating the contrast state of the subject image, i.e., the focus state of the imaging optical system, and luminance information indicating the exposure state. The signal processing circuit 202 also outputs the video signal to a display unit 204, which displays the video signal as a live view image used to check the composition, focus state, and the like. The signal processing circuit 202 also outputs the video signal to a recording processing unit 203. The recording processing unit 203 stores the video signal in an external memory or the like as still images or moving image data.

[0015] Camera microcomputer 206 as a camera control unit controls camera body 200 in response to inputs from an image capture instruction switch and various setting switches included in operation unit 205. Camera microcomputer 206 also includes a communication unit (camera communication unit) capable of communicating with interchangeable lens 100. Camera microcomputer 206 transmits control commands related to the light amount adjustment operation of aperture unit 103 according to luminance information and the focus adjustment operation of focus lens 105 according to focus information to lens microcomputer 111 via the communication unit. As described below, camera microcomputer 206 includes a calculation unit that calculates the depth of field based on first information transmitted from interchangeable lens 100 and third information stored in camera body 200.

[0016] The interchangeable lens 100 has an imaging optical system (101 to 105), control units that control actuators that drive the imaging optical system, an operation ring 110 for operating the focus lens 105, and a lens microcomputer 111.

[0017] The lens microcomputer 111 is a lens control unit that controls the operation of each unit in the interchangeable lens 100. The lens microcomputer 111 includes a communication unit (lens communication unit) that can communicate with the camera body 200, and receives a control command transmitted from the camera body 200 via the communication unit, and receives a transmission request for lens data. The lens microcomputer 111 also performs lens control corresponding to the control command, and transmits lens data corresponding to the transmission request to the camera body 200. The lens microcomputer 111 also outputs commands to the aperture control unit 107 and the focus lens control unit 109 in response to a command related to light amount adjustment or a command related to focusing among the control commands. The aperture control unit 107 and the focus lens control unit 109 drive the aperture unit 103 and the focus lens 105, respectively, according to the command from the lens microcomputer 111. This allows the aperture unit 103 and the focus lens 105 to perform a light amount adjustment process and an autofocus process that controls a focus adjustment operation. Furthermore, the lens microcomputer 111 outputs a command to the focus lens control unit 109 in accordance with the amount of operation of the operation ring 110 to drive the focus lens 105 and control the focus adjustment operation.

[0018] The imaging optical system includes a field lens 101, a zoom lens 102 that changes the magnification, an aperture unit 103 that adjusts the amount of light, an image shake correction lens 104, and a focus lens 105 that adjusts the focus. The zoom lens 102 is movable in a direction along an optical axis OA indicated by a dashed line in the figure (optical axis direction), and is driven in the optical axis direction by a user operating a zoom operation unit connected to a zoom mechanism (not shown). This causes the movement of the zoom lens 102 to change the magnification (zoom), changing the focal length of the imaging optical system.

[0019] The zoom lens position detection unit 106 detects the zoom lens position using a position detection sensor such as a variable resistor, and outputs position data of the zoom lens 102 to the lens microcomputer 111. The position data output from the zoom lens position detection unit 106 is used by the lens microcomputer 111 for zoom tracking control, which will be described later.

[0020] The aperture unit 103 is configured to include aperture blades and sensors such as Hall elements. The state of the aperture blades is detected by the aforementioned sensors and output to the lens microcomputer 111. The aperture control unit 107 outputs a drive signal according to a command from the lens microcomputer 111 to drive an actuator such as a stepping motor or a voice coil motor. This allows the aperture unit 103 to adjust the amount of light.

[0021] The image stabilization lens 104 reduces image shake caused by camera shake or the like by moving in a direction perpendicular to the optical axis OA of the imaging optical system. The image stabilization lens control unit 108 outputs a drive signal to drive the anti-shake actuator according to the shake detected by a shake sensor (not shown) such as a vibration gyroscope, and in accordance with a command from the lens microcomputer 111. This allows anti-shake processing to be performed that controls the shift operation of the image stabilization lens 104.

[0022] The focus lens 105 is movable in the optical axis direction, and detects the position of the focus lens 105 using a position detection sensor such as a photointerrupter and outputs the position data to the lens microcomputer 111. The focus lens control unit 109 outputs a drive signal in accordance with a command from the lens microcomputer 111 to drive an actuator such as a stepping motor and move the focus lens 105 to perform focus adjustment.

[0023] In addition, the focus lens 105 corrects image plane fluctuations caused by the magnification change caused by the zoom lens 102. In a rear focus type variable magnification optical system, the image plane fluctuations caused when the zoom lens 102 is moved to change the magnification are corrected by moving the focus lens 105, thereby performing zoom tracking control to maintain the in-focus state.

[0024] Here, the zoom tracking control will be described with reference to FIG. 2. FIG. 2 is a diagram showing electronic cam data (tracking curve) for each subject distance (distance from the image plane to the object plane (subject)). In FIG. 2, the horizontal axis indicates the position of the zoom lens 102 (zoom lens position), and the vertical axis indicates the position of the focus lens 105 (focus lens position). In order to perform the zoom tracking control, information on electronic cam data (tracking curve) is stored in a memory (internal memory) (not shown) mounted on the lens microcomputer 111. As shown in FIG. 2, the electronic cam data is data indicating the relationship between the zoom lens position and the focus lens position set to maintain a focused state according to the subject distance. The lens microcomputer 111 outputs a control command to the focus lens control unit 109 based on the electronic cam data, and drives the focus lens 105 to perform tracking control.

[0025] In each embodiment, the electronic cam data is created based on focus sensitivity, which is the amount of image plane movement per unit drive amount of focus lens 105. However, as shown in Fig. 2, the electronic cam data actually stored in memory is data corresponding to a plurality of representative subject distances A to C, and is data indicating the focus lens position relative to a representative zoom lens position (representative point). The focus lens position can be calculated by calculating the ratio of the distance to a plurality of representative points close to the zoom lens position other than the representative point, and performing linear interpolation according to the ratio.

[0026] The imaging device 10 of each embodiment can perform focus adjustment by driving the focus lens 105 in autofocus (AF) for automatic focus adjustment and manual focus (MF) for manual focus adjustment. In AF, the camera microcomputer 206 calculates the in-focus position of the focus lens 105 based on an AF evaluation value corresponding to a video signal generated by the imaging element 201, and transmits a control command related to focusing to the lens microcomputer 111 via the camera communication unit. In response to the control command transmitted from the camera microcomputer 206, the lens microcomputer 111 outputs a command to the focus lens control unit 109 to drive the focus lens 105 to control the focus adjustment operation. In MF, the lens microcomputer 111 outputs a command to the focus lens control unit 109 according to the amount of operation of the operation ring 110, and drives the focus lens 105 to control the focus adjustment operation.

[0027] Next, referring to FIG. 3, a distance indicator (distance information indicator) according to the position of the focus lens 105 of the interchangeable lens 100, which is displayed on the display unit 204 of the camera body 200, will be described. FIG. 3 is a diagram showing the distance indicator in each embodiment. As shown in FIG. 3, the distance indicator includes a lens driving area which is the driving range of the focus lens 105, a distance scale display indicating the distance, and a lens position indicating the in-focus position of the focus lens 105. The distance indicator also includes a lens non-driving area indicating that the lens driving area changes depending on the focal length, etc., and a lens driving area. Hereinafter, these are collectively referred to as a distance indicator bar. In the example of FIG. 3, the focus lens 105 can be driven so that it can focus on a subject at a distance of about 0.2 m to infinity. In addition, the area where the focus lens 105 is focused on a subject closer than 0.2 m due to settings such as zoom cannot be driven. In addition, it is shown that the current focus lens 105 is in a position to focus on a subject at a distance of 3 m.

[0028] The limit area in FIG. 3 is an area where focus adjustment is not performed by AF. For example, by setting a limit to the object distance close to the imaging device 10, it is possible to quickly focus on a distant object. In this way, when the user knows the distance range of the object in advance, the user may limit the AF-enabled range by setting, and the area where AF is not performed is displayed as the limit area. Alternatively, the optical performance of the interchangeable lens 100 makes it impossible to accurately calculate the AF evaluation value, so the MF-only area is displayed, where focus adjustment by AF is not possible and only focus adjustment by MF is possible. The MF-only area may have a configuration in which the minimum shooting distance changes depending on the position of the zoom lens 102, and the shooting distance position that was an AF-enabled area on the WIDE side becomes an MF-only area on the TELE side, and the area is switched depending on the zoom position. EXAMPLES

[0029] Next, a description will be given of a first embodiment of the present invention. If an attempt is made to display an index of distance information without taking into consideration differences in specs (performance and specifications) of the interchangeable lens 100, such as a wide-angle lens or a telephoto lens, and differences in specs, such as the number of pixels, of the display unit 204 of the camera body 200, the following problems arise.

[0030] 4 is a diagram showing distance information (distance display bar) displayed on display unit 204 of camera body 200. In addition to distance information, display unit 204 displays a video signal obtained by performing various image processing on a signal obtained by image processing circuit 202 after image pickup element 201 photoelectrically converting an image formed by interchangeable lens 100. Display unit 204 also displays settings of camera body 200 such as camera mode, shutter speed, aperture value (F-number), exposure compensation, ISO sensitivity, etc.

[0031] 4, the lens microcomputer 111 transmits information such as "0.2 m," "0.5 m," "1 m," "3 m," and "∞" as representative indices of distance information to the camera microcomputer 206. At this time, it is necessary to transmit the positions at which to display each representative indices. If the left end of the distance display bar is set as the display start position and a unit of screen resolution such as "100 pixels" from the display start position is specified, the lens microcomputer 111 needs to know in advance the total length of the distance display bar.

[0032] FIG. 5 is a diagram showing a case where the display position of the distance display bar is specified in pixel units. For example, consider a case where the lens microcomputer 111 does not know the total length of the distance display bar, and the number of effective pixels of the display unit 204 of the camera body 200 increases, and information is exchanged in the same manner as described above. In this case, when it is desired to display as shown in FIG. 5(A), it is compressed as shown in FIG. 5(B), and accurate information cannot be displayed as distance information. Therefore, the lens microcomputer 111 needs to obtain the total length (number of pixels) of the distance display bar from the camera microcomputer 206, calculate information on the representative index position based on the obtained total length (number of pixels) of the distance display bar, and transmit it to the camera microcomputer 206. However, even if the items to be displayed on the display unit 204 of the camera body 200 are not only the representative index described above but also a wide range of items such as the lens driving range and limit range described above, it is necessary to perform calculation processing so as not to affect the drive control of the interchangeable lens 100, such as focus, aperture, and vibration isolation. In addition, if a delay occurs in the communication of information for display, there is a concern that it will cause a display delay and reduce usability for the user. For this reason, it is necessary to suppress the communication volume of display information and the processing load imposed on each calculation.

[0033] Therefore, in this embodiment, the lens microcomputer 111 not only transmits information (first information) appropriate for the specifications of the interchangeable lens 100 to the camera microcomputer 206, but also transmits normalized values ​​(second information) as necessary to the camera microcomputer 206. This makes it possible to properly display information appropriate for the interchangeable lens 100 on the display unit 204 of the camera body 200.

[0034] Next, normalization will be described with reference to FIG. 6. FIG. 6 is a diagram showing an example in which the distance display bar displayed on the display unit 204 of the camera body 200 is divided into 100 parts. As shown in FIG. 6, if the entire distance display bar is equally divided, with the left end being 1 and the right end being 100, one of the representative indices, "0.2 m", is located at the position of "7". Other information includes the representative indices "0.5 m" at "37", "1 m" at "62", "3 m" at "83", "∞" at "96", the lens non-driveable area at "7", the limit area at "37", and the lens position at "83". The lens microcomputer 111 transmits this information (location information) to the camera microcomputer 206. This information is normalized by the lens microcomputer 111 to values ​​from 1 to 100 based on various information such as distance information held by the interchangeable lens 100. The camera microcomputer 206 displays distance information on the display unit 204 based on the information received from the lens microcomputer 111 .

[0035] Next, the depth of field will be described with reference to Fig. 7. Fig. 7 shows a formula (approximation formula) for calculating the depth of field. The depth of field is the distance at which a photograph appears to be in focus. The depth of field is calculated by the camera microcomputer 206 using the formula shown in Fig. 7. Information (third information) that is the criterion for whether or not an image is in focus, that is, information on the permissible circle of confusion diameter δ and information on the set aperture value F (F-number at the time of shooting), is stored in a storage unit of the camera body 200 (such as an internal memory of the camera microcomputer 206).

[0036] On the other hand, information on the focal length f and information on the object distance L (first information) differ depending on the position of the focus lens 105 or the zoom lens 102, and are stored in the memory of the interchangeable lens 100 (for example, the internal memory of the lens microcomputer 111). For this reason, the camera body 200 needs to receive these pieces of information from the interchangeable lens 100 by communication. The camera body 200 calculates the depth of field based on the above-mentioned information, and the depth of field calculated here is the depth of field of the absolute distance. Since the camera body 200 displays the normalized information (second information) transmitted from the interchangeable lens 100 as is on the display unit 204, it is necessary to normalize and display the information of the absolute distance. The normalization calculation is performed by the interchangeable lens 100. For this reason, the camera body 200 receives second information (such as a coefficient of an approximation formula (polynomial approximation)) for normalizing the depth of field of the absolute distance from the interchangeable lens 100 by communication, performs a normalization calculation of the depth of field, and then displays it on the display unit 204. The second information is, for example, a coefficient of an approximation formula (such as a polynomial approximation) that normalizes distance information of the focusing range calculated using the first information in order to display the information on the display unit 204.

[0037] The first information is not limited to the object distance (the distance from the front principal point position to the subject (object plane)), but may be the subject distance (the distance from the image plane to the subject). In other words, the first information only needs to include at least one of the focal length, the subject distance, the object distance, and the front principal point position.

[0038] Next, a process for displaying the depth of field on the display unit 204 of the camera body 200 will be described with reference to Fig. 8. Fig. 8 is a flowchart showing the process for displaying the depth of field.

[0039] First, in step S101, the camera microcomputer 206 in the camera body 200 requests the lens microcomputer 111 in the interchangeable lens 100 for initial information required for the distance display bar. The initial information is information that does not change depending on the state of the interchangeable lens 100, and includes the aforementioned value of the representative index and the position of the representative index, information for normalization, etc. Next, in step S102, the camera microcomputer 206 determines whether or not reception of the initial information requested in step S101 has been completed. If reception of the initial information has not been completed, step S20 is repeated. On the other hand, if reception of the initial information has been completed, the process transitions to step S103.

[0040] In step S103, the camera microcomputer 206 requests the interchangeable lens 100 to provide current information (current distance display information) required for displaying the distance display bar. The current information is information that changes according to the state of the interchangeable lens 100, such as the aforementioned lens non-drivable area, limit area, lens position, focal length, subject distance, etc. This information is information that changes according to, for example, the position of the zoom lens 102 and the position of the focus lens 105. Next, in step S104, the camera microcomputer 206 determines whether or not reception of the current distance display information requested in step S103 has been completed. If reception of the current distance display information has not been completed, the process returns to step S103. On the other hand, if reception of the current distance display information has been completed, the process transitions to step S105.

[0041] In step S105, the camera microcomputer 206 calculates the depth of field based on the current distance display information received from the interchangeable lens 100 in step S103 and the calculation formula shown in Fig. 7. Next, in step S106, the camera microcomputer 206 performs normalization processing (depth of field normalization processing) for displaying the depth of field calculated in step S105 on the distance display bar of the display unit 204. The normalization calculation is performed based on the normalization information transmitted from the interchangeable lens 100, as described above.

[0042] Next, in step S107, the camera microcomputer 206 determines whether or not the display of the distance display bar is enabled. If the display of the distance display bar is enabled, the camera microcomputer 206 displays the distance display bar on the display unit 204 (if it is already displayed, the display information of the display unit 204 is updated), and the process proceeds to step S103. As described above, for information (first information) that changes depending on the state of the interchangeable lens 100, the camera microcomputer 206 periodically requests information from the interchangeable lens 100. The camera microcomputer 206 then changes the display content of the display unit 204 based on the content received from the interchangeable lens 100. On the other hand, if the display of the distance display bar is disabled in step S107, the process proceeds to step S109. In step S109, the camera microcomputer 206 hides the distance display on the display unit 204.

[0043] As described above, in this embodiment, the processing performed by the interchangeable lens 100 and the processing performed by the camera body 200 are separated, and the amount of communication is kept to a minimum. This makes it possible to display the depth of field on the display unit 204 of the camera body 200 without affecting the drive control of the interchangeable lens 100, thereby improving user operability.

[0044] Furthermore, information on the maximum F-number may be included in the initial information received in step S101 or the current distance display information received in step S103. In this case, as shown in Fig. 9, it is possible to display the maximum depth of field according to the maximum F-number that can be set in the interchangeable lens 100, superimposed on the distance display bar described above, for example, by changing the color or pattern. Also, the absolute value of the depth of field calculated in step S105 may be displayed digitally on the distance display bar. The position of the digital display can also be calculated by performing normalization processing as described above. EXAMPLES

[0045] Next, a second embodiment of the present invention will be described. When the depth of field calculated in step S105 of FIG. 8 is shallow, it is difficult to display the depth of field on the distance display bar with good visibility. As shown in FIG. 6, when the depth of field is smaller than the minimum display unit "1" of the distance display bar in a configuration in which the distance display bar is displayed in 100 divisions, it is difficult to display the depth of field, and even if the depth of field "1" is displayed, the visibility is not good. In addition, when the interchangeable lens 100 is, for example, a macro lens, it is assumed that there are many shots with a shallow depth of field, and the depth of field is not always displayed, making it difficult for the user to visually grasp the depth of field. Therefore, in this embodiment, an enlarged display is performed in which a part of the distance display bar is enlarged and displayed. The enlarged display is a display process for improving visibility when the width of the depth of field is narrow and cannot be displayed on a normal distance display bar, or can be displayed but is narrow and the visibility is poor.

[0046] Figures 10 and 11 are diagrams showing examples of enlarged displays of parts of the distance display bar. Figure 10 shows an example of an enlarged display with the lens position index currently at 3 m at the center, the closest side at 2.8 m, and the infinity side at 3.3 m. Figure 11 shows an example of a new display added to the top of the distance display bar. The enlarged display section shows indicators representing the depth of field on the left and right of the lens position index, and instead of the position of the lens position index moving, the representative index value is displayed to move.

[0047] 10 and 11, the normalized depth of field index width is expressed in units of 100 divisions of the entire distance display bar, so it cannot be used for display as is and requires complementation processing in the enlarged display dimension. For example, in the first embodiment, the normalization is performed to a value from "1" to "100" during normalization calculation, so the decimal points are truncated for use in the display, but there is a method of using it as the index width for enlarged display without truncation.

[0048] Specifically, when the range of "80" and "90" in the overall index dimension is enlarged and displayed, the area between "80" and "90" is further divided into 100 parts as shown in FIG. 12. FIG. 12 is a diagram showing an example of a distance display bar being enlarged and divided into 100 parts. If the numerical values ​​before decimal point truncation after normalization calculation are "83.3" for the front depth of field and "86.5" for the rear depth of field, the range from "33" to "65" in the enlarged display dimension is set as the depth of field. This method makes it possible to properly display the depth of field even when enlarged.

[0049] However, since the normalization information for displaying the depth of field on the distance display bar sent from the interchangeable lens 100 is optimized for displaying the distance display bar by dividing it into 100, it is possible that the depth of field in the enlarged display may not be accurately represented. In such a case, it is also possible for the camera body 200 to request and receive information from the interchangeable lens 100 for displaying the depth of field in the enlarged display on the distance display bar, and to perform calculations based on the information for enlarged display received from the interchangeable lens 100.

[0050] Furthermore, since the depth of field is often shallow during macro shooting, the camera body 200 may switch whether or not to perform enlarged display depending on the position of the focus lens 105 of the interchangeable lens 100. Furthermore, since the calculation method used when the camera body 200 determines that macro shooting is being performed will result in large errors, a more accurate calculation method may be used instead of the approximation shown in Fig. 7. Note that the method of expressing the depth of field in enlarged display can be modified in various ways, such as a method using various types of complementary calculations in the camera body 200, a method in which the interchangeable lens 100 has information for enlarged display, or a combination of these.

[0051] Next, the enlargement process of the distance display bar in this embodiment will be described with reference to Fig. 13. Fig. 13 is a flow chart showing the enlargement process of the distance display bar. Note that steps S201 to S206 in Fig. 13 are similar to steps S101 to S106 in Fig. 8, respectively, and therefore their description will be omitted.

[0052] In step S207, the camera microcomputer 206 determines whether the normalized depth of field calculated in step S206 is equal to or less than a certain value (equal to or less than a predetermined value). If the normalized depth of field is equal to or less than the certain value, the process proceeds to step S208. In step S208, the camera microcomputer 206 turns on the enlarged display flag. Then, in step S210, the camera microcomputer 206 performs the enlarged display process described above. If necessary, the camera microcomputer 206 requests information for enlarged display from the interchangeable lens 100, and performs calculations related to the enlarged display based on the information transmitted from the interchangeable lens 100. When the camera microcomputer 206 completes the enlarged display process, the process proceeds to step S211.

[0053] On the other hand, if the normalized depth of field is greater than the fixed value in step S207, the process proceeds to step S209. In step S209, the camera microcomputer 206 turns off the enlarged display flag and proceeds to step S211.

[0054] In step S211, the camera microcomputer 206 determines whether or not the display of the distance display bar is enabled. If the display of the distance display bar is enabled, the process transitions to step S212. In step S212, the camera microcomputer 206 displays the distance display bar on the display unit 204, and updates the display content if it is already displayed. Next, in step S213, the camera microcomputer 206 determines whether or not the enlarged display flag is ON. If the enlarged display flag is ON, the process transitions to step S214. On the other hand, if the enlarged display flag is OFF, the process transitions to step S215.

[0055] In step S214, the camera microcomputer 206 displays the enlarged display section, and updates the display content of the enlarged display section if it is already displayed. As in the first embodiment, for information (first information) that changes according to the state of the interchangeable lens 100, the camera microcomputer 206 periodically requests information from the interchangeable lens 100, and periodically changes the display content of the display section 204 based on the received information. In step S215, the camera microcomputer 206 hides the enlarged display section.

[0056] If the display of the distance display bar is disabled in step S211, the process proceeds to step S216, in which the camera microcomputer 206 hides the distance display.

[0057] In this embodiment, the second information changes according to the display width of the display unit 204 (changes due to enlarged display). Preferably, the camera microcomputer 206 switches the display format on the display unit 204 (performs enlarged display) when the depth of field is smaller than a predetermined value. Also preferably, the camera microcomputer 206 switches the display format when the position of the focus lens 105 is closer than a predetermined position (performs enlarged display in the case of macro photography). Also preferably, the camera microcomputer 206 switches the calculation method (approximation formula) for the depth of field when the position of the focus lens 105 is closer than a predetermined position (switches the calculation method in the case of macro photography).

[0058] According to this embodiment, even if the depth of field displayed on the distance display bar is narrow, the visibility for the user can be improved by enlarging the display.

[0059] (Other Examples) The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-mentioned embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0060] As described above, in each embodiment, the lens device (interchangeable lens 100) has a communication unit (lens microcomputer 111). The communication unit transmits to the imaging device first information for calculating the depth of field and second information for normalizing the depth of field to the display format of the display unit 204 of the imaging device (camera body 200). The imaging device has a calculation unit (camera microcomputer 206) and a display unit 204. The calculation unit calculates the depth of field based on the first information transmitted from the lens device and the third information stored in the imaging device. The display unit 204 normalizes the depth of field and displays information related to the depth of field based on the second information transmitted from the lens device.

[0061] According to each embodiment, it is possible to provide a lens device, an imaging device, a control method for a lens device, a control method for an imaging device, and a program that are capable of displaying information regarding depth of field on a display unit of the camera body to improve user operability.

[0062] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0063] 100 Interchangeable lenses (lens devices) 101 Field lens (imaging optical system) 102 Zoom lens (imaging optical system) 103 Aperture unit (imaging optical system) 104 Image stabilization lens (imaging optical system) 105 Focus lens (imaging optical system) 111 Lens microcomputer (communication section)

Claims

1. A lens device that can be attached to an imaging device having a display unit, An imaging optical system; A communication unit capable of communicating with the imaging device, The communication unit is lens information obtained by normalizing information about the imaging optical system to a display format of the display unit; First information for the imaging device to calculate a depth of field; and second information for normalizing the depth of field to a display format of the display unit by the imaging device, The lens device, wherein the display unit displays the lens information and information about the depth of field normalized based on the second information.

2. 2. The lens apparatus according to claim 1, wherein the first information includes at least one of a focal length, a subject distance, an object distance, and a front principal point position.

3. 3. The lens device according to claim 1, wherein the first information is information periodically requested from the image capturing device to the lens device.

4. 4. The lens apparatus according to claim 1, wherein the first information differs depending on a position of a focus lens or a zoom lens of the imaging optical system.

5. 5. A lens device according to claim 1, wherein the second information is a coefficient of an approximation formula that normalizes distance information of the focus range calculated using the first information in order to display it on the display unit.

6. 6. The lens device according to claim 1, wherein the second information changes depending on a display width of the display section.

7. the first information is information for the imaging device to calculate an absolute distance corresponding to the depth of field, 5. The lens device according to claim 1, wherein the second information is information for the imaging device to normalize the absolute distance to the display format.

8. 8. The lens apparatus according to claim 7, wherein the second information includes a coefficient of an approximation formula used to normalize the absolute distance in the focusing range calculated using the first information.

9. A lens device as described in any one of claims 1 to 8, characterized in that the lens information is information regarding at least one of the position of the lens undriveable area, the position of the limit area, and the lens position to be displayed on the display unit.

10. An imaging device to which a lens device having an imaging optical system can be attached, An imaging element; A display unit; a communication unit capable of communicating with the lens device; A calculation unit that calculates a depth of field, The communication unit is lens information obtained by normalizing information about the imaging optical system to a display format of the display unit; First information for the imaging device to calculate a depth of field; and second information for normalizing the depth of field to a display format of the display unit from the lens device. The calculation unit calculates the depth of field based on the first information and third information stored in the imaging device; The imaging device, characterized in that the display unit displays the lens information and information regarding the depth of field normalized based on the second information.

11. 11. The imaging apparatus according to claim 10, wherein the third information is information regarding a permissible circle of confusion diameter and an F-number.

12. 12. The imaging apparatus according to claim 10, wherein the calculation section switches a display format on the display section when the depth of field is smaller than a predetermined value.

13. 13. The imaging apparatus according to claim 10, wherein the calculation section switches the display format when a position of a focus lens in the imaging optical system is closer than a predetermined position.

14. 14. The imaging apparatus according to claim 10, wherein the calculation section switches the method of calculating the depth of field when a position of a focus lens in the imaging optical system is closer than a predetermined position.

Images