Optical instrument and method for controlling the same

Abstract

To automatically prevent fall of an object surface in shifting of a photographic range.SOLUTION: An optical instrument 100 has: a photographic optical system including a first shift lens 102 and a second shift lens 103 that are movable in a direction orthogonal to an optical axis; and control means 150 that controls the drive of the first and second shift lenses so as to shift a photographic range. In shifting of the photographic range by a target amount, the control means controls the drive of the first and second shift lenses so as to prevent the amount of fall of an object surface caused by the drive of the first and second shift lenses from exceeding a first predetermined value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an optical device such as an interchangeable lens having a tilt / shift function. [Background technology]

[0002] Tilt photography is photography in which at least a part of the photographing optical system is tilted with respect to the imaging plane in order to focus on the entire object surface tilted with respect to the plane perpendicular to the optical axis of the photographing optical system. Shift photography is photography in which at least a part of the photographing optical system is shifted with respect to the imaging plane so as to shift the photographing range in a direction perpendicular to the optical axis of the photographing optical system. These tilt photography and shift photography are originally used for different purposes. However, for example, adjusting the tilt amount in tilt photography also causes a shift in the photographing range, and therefore it is necessary to adjust the shift amount.

[0003] Patent Document 1 discloses a technique for correcting a shift in the imaging range caused by adjusting the amount of tilt. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-91027 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, contrary to Patent Document 1, when the shift amount is adjusted in shift photography, the object plane tilts, and therefore it becomes necessary to adjust the tilt amount to correct this tilt of the object plane, which requires the user to carry out complicated operations.

[0006] The present invention provides an optical device that can automatically suppress tilt of the object plane when the shooting range is shifted. [Means for solving the problem]

[0007] An optical device according to one aspect of the present invention includes an imaging optical system including a first shift lens and a second shift lens movable in a direction perpendicular to an optical axis, and a control means for controlling the driving of the first and second shift lenses so as to shift an imaging range. The control means controls the driving of the first and second shift lenses so that the amount of inclination of an object surface caused by the driving of the first and second shift lenses does not exceed a first predetermined value when shifting the imaging range by a target amount.

[0008] A control method according to another aspect of the present invention is applied to an optical device having an imaging optical system including a first shift lens and a second shift lens movable in a direction perpendicular to an optical axis. The control method includes a step of controlling the driving of the first and second shift lenses so as to shift the imaging range. In the step, when the imaging range is shifted by a target amount, the driving of the first and second shift lenses is controlled so that the amount of inclination of the object surface caused by the driving of the first and second shift lenses does not exceed a first predetermined value. Note that a program for causing the optical device to execute a process according to the above control method also constitutes another aspect of the present invention. Effect of the Invention

[0009] According to the present invention, it is possible to automatically suppress tilt of the object surface when the shooting range is shifted. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing the configuration of a camera system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing a photographing composition in the first embodiment. [Diagram 3] 5A to 5C are diagrams illustrating a composition shift in the first embodiment. [Figure 4] 4 is a diagram showing a change in position of the shift lens group when the composition shift shown in FIG. 3 is performed. [Diagram 5] 4 is a diagram showing a change over time in the position of the shift lens group during the composition shift shown in FIG. 3. [Figure 6]8A to 8C are diagrams illustrating another composition shift in the first embodiment. [Figure 7] 7A and 7B are diagrams showing a change in position of the shift lens group when the composition shift shown in FIG. 6 is performed. [Figure 8] The change in the position of the shift lens group over time when the composition shift is performed is shown in Fig. 6. [Figure 9] 5 is a flowchart showing a lens shift process in the first embodiment. [Figure 10] FIG. 11 is a diagram showing a photographing composition in the second embodiment. [Figure 11] 13A to 13C are diagrams illustrating a composition shift in the second embodiment. [Figure 12] 11A and 11B are diagrams showing a change in position of the shift lens group when the composition shift shown in FIG. 10 is performed. [Figure 13] 11A and 11B are diagrams showing a change over time in the position of the shift lens group during the composition shift shown in FIG. 10. [Figure 14] 10 is a flowchart showing a lens shift process in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. EXAMPLES

[0012] FIG. 1 shows the configuration of a lens-interchangeable camera system including a lens unit (lens apparatus) 100 as an optical device according to a first embodiment and a camera body 200 as an imaging apparatus.

[0013] The lens unit 100 is mechanically and electrically connected to the camera body 200 via a mount 300. The lens unit 100 has a photographing optical system including, in order from the incident direction of light from a subject, a field lens 101, a first shift lens 102, a second shift lens 103, an aperture 106, a variable magnification (zoom) lens 104, and a focus lens 105.

[0014] The first shift lens 102, the second shift lens 103, and the focus lens 105 are held by lens holding frames 111, 112, and 113, respectively. The lens holding frames 111 and 112 are held by a guide shaft (not shown) so as to be movable in directions perpendicular to the optical axis of the photographing optical system (X and Y directions in FIG. 1). The lens holding frame 113 is held by a guide shaft (not shown) so as to be movable in the optical axis direction of the photographing optical system (Z direction in FIG. 1).

[0015] The aperture 106 changes its opening diameter and adjusts the amount of light when aperture blades 106a and 106b are driven by an aperture motor 125. The aperture motor 125 is driven by a drive circuit 135. The position of the aperture 106 (opening diameter) is detected by an aperture position sensor 127.

[0016] The zoom lens 104 moves in the optical axis direction when a zoom operation ring (not shown) is rotated by a user, thereby changing the focal length (angle of view) of the photographing optical system. The position of the zoom lens 104 is detected by a zoom position sensor (not shown). The focus lens 105 is driven in the optical axis direction by a focus motor 126 to perform focusing. The focus motor 126 is driven by a drive circuit 136. The position of the focus lens 105 is detected by a focus position sensor (not shown).

[0017] The first and second shift lenses 102, 103 move (shift) in a shift direction perpendicular to the optical axis to produce a shift effect and a tilt effect. The shift effect is to shift the shooting range through the shooting optical system in a direction perpendicular to the optical axis. The tilt effect is to tilt the object plane of the shooting optical system relative to a plane perpendicular to the optical axis. The shift effect can be produced by shifting the first and second shift lenses 102, 103 in the same direction, and the tilt effect can be produced by shifting them in opposite directions.

[0018] The first shift lens 102 is driven in the shift direction by each of shift motors 121 and 122. The second shift lens 103 is driven in the shift direction by each of shift motors 123 and 124. The shift motors 121 and 122 are driven by drive circuits 131 and 132, respectively, and the shift motors 123 and 124 are driven by drive circuits 133 and 134, respectively. The positions of the first and second shift lenses 102 and 103 are detected by shift position sensors (not shown).

[0019] Lens control unit 150, which is a computer configured with a microprocessor, controls drive circuits 131-136 and the like and performs various processes in response to various commands from camera body 200. Lens control unit 150 also transmits various types of lens information to camera body 200 via lens communication unit 151 and receives camera information from camera body 200.

[0020] The attitude detection unit 141 is provided to detect angular shake (camera shake) applied to the lens unit 100 due to camera shake or the like and a change in the attitude of the camera body 200, and outputs detection signals such as angular velocity signals to the lens control unit 150.

[0021] The position storage operation unit 142 is an operation member operated by a user to cause the lens control unit 150 to store the positions of the first and second shift lenses 102 and 103, the zoom lens 104, and the focus lens 105 at the time of the operation. The position reproduction operation unit 143 is an operation member operated by a user to cause the lens control unit 150 to move the first and second shift lenses 102 and 103, the zoom lens 104, and the focus lens 105 to the positions stored by the operation of the position storage operation unit 142. Specifically, the lens control unit 150, which detects the operation of the position reproduction operation unit 143, controls the drive circuits 131 to 134, 136 so that the first and second shift lenses 102 and 103, the zoom lens 104, and the focus lens 105 move to the stored positions.

[0022] The camera body 200 has an imaging element 201 such as a CCD sensor or a CMOS sensor that photoelectrically converts (captures) an image of a subject formed by an imaging optical system. The camera body 200 also has an A / D conversion circuit 202, a signal processing circuit 203, a recording unit 204, a camera communication unit 205, a display unit 206, a camera control unit 207, and an attitude detection unit 208.

[0023] An analog imaging signal is output from the imaging element 201, which photoelectrically converts the subject image. The analog imaging signal is converted into a digital imaging signal by an A / D conversion circuit 202 and input to a signal processing circuit 203. The signal processing circuit 203 performs various image processes on the input digital imaging signal to generate image data.

[0024] The image data generated by the signal processing circuit 203 is sent to a recording unit 204 and recorded, or sent to a display unit 206 and displayed as a display image (live view image). A user can check the shooting composition, focus state, etc. by looking at the displayed image on the display unit 206. A touch sensor is provided on the display unit 206, and the user can perform various inputs by performing a touch operation.

[0025] The camera control unit 207, which is a computer configured by a microprocessor, controls the camera body 200 and performs various processes in response to inputs from a shooting instruction switch and various setting switches provided on an operation unit (not shown). The camera control unit 207 can also communicate with the lens control unit 150 through the communication unit 205, and receives lens information requested from the lens control unit 150 and transmits camera information to the lens control unit 150. The camera control unit 207 also transmits various commands, such as a tilt / shift command, a focus command, and an aperture command, to the lens control unit 150. The camera control unit 207 also generates brightness information indicating an exposure state, focus information indicating a focus state, and subject distance information indicating a distance to a subject from a digital imaging signal or image data. Then, the camera control unit 207 performs automatic exposure control (AE) using the brightness information and autofocus control (AF) using the focus information, and transmits subject distance information to the lens control unit 150 in a lens shift process described later. A distance sensor for acquiring subject distance information may be provided in the camera body 200.

[0026] Like the attitude detection section 141 of the lens unit 100 , the attitude detection section 208 detects camera shake and the attitude of the camera body 200 , and outputs a detection signal to the camera control section 207 .

[0027] Next, a description will be given of a method for shifting the photographic composition by controlling the positions of the first and second shift lenses 102, 103 and the focus lens 105. In this description, the first and second shift lenses 102, 103 are also collectively referred to as a shift lens group.

[0028] FIG. 2 shows an example of a scene including subjects (a tree, a post office or other building, and the sun). FIG. 3(a)-(c) show how the shooting range is shifted from the left end to the right end of the scene in FIG. 2 (hereinafter referred to as composition shift). FIG. 4(a)-(c) respectively show the positions of the first and second shift lenses 102, 103 viewed from the Y direction when the shooting compositions of FIG. 3(a)-(c) are set. In FIG. 4(a)-(c), the lines in the first and second shift lenses 102, 103 indicate the inclination of the object surface with respect to a plane perpendicular to the dashed line indicating the center of the optical axis.

[0029] First, as shown by a frame at the left end of FIG. 3(a), the user adjusts the positions of the shift lens group and the focus lens 105 so as to obtain a shooting composition before the composition shift. The driving of the shift lens group may be controlled according to the operation of an operation unit (not shown) provided on the camera body 200, or according to the operation of an operation unit (not shown) provided on the lens unit 100. In this state, as shown in FIG. 4(a), both the first and second shift lenses 102 and 103 are shifted in the +X direction with respect to the center of the optical axis, and a tilt occurs on the object surface. For this reason, the subject (post office) in the right area in the shooting composition shown in FIG. 3(a) is in focus, but the subject (tree) in the left area surrounded by the dashed line is out of focus.

[0030] 3(a), the user inputs a composition shift amount as a target amount of composition shift to the lens control unit 150. The composition shift amount is input through a user's operation on an operation unit provided on the camera body 200 or the lens unit 100. This operation also includes a touch operation on an input screen (GUI) displayed on the display unit 206.

[0031] The lens control unit 150 drives the shift lens group and the focus lens 105 at a predetermined speed so that the photographic composition is shifted by the input composition shift amount and the subject (a rectangular parallelepiped building) in the photographic composition is brought into focus. At this time, the first and second shift lenses 102 and 103 both shift to the center of the optical axis as shown in FIG. 4(b), and as a result, the tilt of the object surface becomes zero. Since the surface of the subject in the photographic composition is parallel to the imaging surface of the image sensor 201, the entire subject in the photographic composition is brought into focus as shown in FIG. 3(b).

[0032] Furthermore, the user inputs the amount of composition shift to the lens control unit 150 from the state shown in FIG. 3(b). The lens control unit 150 drives the shift lens group and the focus lens 105 at a predetermined speed so that the photographic composition is shifted by the input amount of composition shift and so that the subject (a building with a sloping roof) in the photographic composition is focused on. At this time, as shown in FIG. 4(c), both the first and second shift lenses 102 and 103 shift in the −X direction from the center of the optical axis, resulting in the object surface being tilted in the opposite direction to that shown in FIG. 4(a). Therefore, the subject (a building with a sloping roof) in the left area of ​​the photographic composition shown in FIG. 3(c) is in focus, but the subject (the sun) in the right area enclosed by the dashed line is out of focus.

[0033] Figures 5(A), (B), and (C) respectively show the change over time in the positions of focus lens 105 and first and second shift lenses 102 and 103 from the states of Figures 3(a) and 4(a) to the states of Figures 3(c) and 4(c). (a), (b), and (c) in Figures 5(A), (B), and (C) respectively show the positions of focus lens 105 and first and second shift lenses 102 and 103 in the states of Figures 3(a) and 4(a), Figures 3(b) and 4(b), and Figures 3(c) and 4(c).

[0034] In Fig. 3(a) and (c), the shift lens group is shifted in the X direction from the optical axis center as shown in Fig. 4(a) and Fig. 4(c), and these optical axes are in a state of being displaced from the optical axis center, so that the object plane tilts. As a result, while the entire shooting composition is in focus in Fig. 3(b), an out-of-focus area occurs in the left area of ​​the shooting composition in Fig. 3(a) and in the right area of ​​the shooting composition in Fig. 3(b), and the user feels uncomfortable. This is because the shift of the shift lens group causes not only a shift effect but also a tilt effect. This tilt effect causes the object plane to tilt, so that a part of the shooting composition is out of focus. For this reason, in this embodiment, this focus deviation is automatically corrected.

[0035] First, as a premise, data on information on composition shift sensitivity indicating the amount of composition shift with respect to the shift amount (position) from the optical axis center of each of the first and second shift lenses 102 and 103 is stored in advance in a memory (storage means) in the lens control unit 150. In addition, data on information on object plane tilt sensitivity indicating the amount of object plane tilt with respect to the shift amount from the optical axis center of each of the first and second shift lenses 102 and 103 is also stored in advance in the memory. The stored data may be a data table of the amount of composition shift and the amount of object plane tilt for each shift amount, or a function indicating each of the composition shift sensitivity and the object plane tilt sensitivity may be stored, and the amount of composition shift and the amount of object plane tilt corresponding to the shift amount of the shift lens may be calculated from the function. Note that the composition shift sensitivity and the object plane tilt sensitivity change not only depending on the positions of the first and second shift lenses 102 and 103, but also depending on the positions of the focus lens 105 and the zoom lens 104. For this reason, it is desirable to prepare data on the composition shift sensitivity and the object plane tilt sensitivity for each position of these lenses.

[0036] Figures 6(a) to (c) show the state of composition shift from the left end to the right end for the scene shown in Figure 2. Also, Figures 7(a) to (c) respectively show the positions of the first and second shift lenses 102, 103 relative to the imaging surface of the image sensor 201 as viewed from the Y direction in a state in which focus deviation caused by the inclination of the object surface is corrected when the shooting compositions of Figures 6(a) to (c) are set. In Figures 7(a) to (c), the lines within the first and second shift lenses 102, 103 represent the inclination of the object surface.

[0037] In Fig. 7(a), the shift amount in the +x direction of the first shift lens 102 is the same as in Fig. 4(a), but the second shift lens 103 is shifted in the +x direction by a larger amount, so that the inclination of the object surface is corrected so as not to exceed the first predetermined value, which is the allowable value (to be approximately 0). As a result, the entire photographic composition is brought into focus as shown in Fig. 6(a). That is, the subject (tree) in the left area, which was out of focus in Fig. 3(a), is also brought into focus.

[0038] The positions of the first and second shift lenses 102, 103 in FIG. 7(b) are the same as those in FIG. 4(b), and the entire subject in the photographing composition is in focus as shown in FIG. 6(b) (FIG. 3(b)).

[0039] In Fig. 7(c), the shift amount in the -x direction of the first shift lens 102 is the same as in Fig. 4(c), but the second shift lens 103 is shifted in the -x direction more greatly to correct the inclination of the object surface to approximately 0 so as not to exceed the first predetermined value. As a result, the entire photographic composition is brought into focus as shown in Fig. 6(c). That is, the subject (sun) in the right-hand area, which was out of focus in Fig. 3(c), is also brought into focus.

[0040] In this manner, each shift lens is driven to a position determined by the drive amount of the first and second shift lenses 102, 103 for the target composition shift and the drive amount of at least one of the first and second shift lenses 102, 103 for preventing the object face tilt amount from exceeding a first predetermined value.

[0041] 8(A), (B), and (C) respectively show the time change in the positions of the focus lens 105 and the first and second shift lenses 102 and 103 from the state of FIG. 6(a) and FIG. 7(a) to the state of FIG. 6(c) and FIG. 7(c). (a), (b), and (c) in FIG. 8(A), (B), and (C) respectively show the positions of the focus lens 105 and the first and second shift lenses 102 and 103 in the states of FIG. 6(a) and FIG. 7(a), FIG. 6(b) and FIG. 7(b), FIG. 6(c) and FIG. 7(c). The change (correction) in the position of the second shift lens 103 shown in FIG. 8(C) is different from the change (indicated by the dotted line in FIG. 8(C)) in the position of the second shift lens 103 shown in FIG. 5(C) for correcting the inclination of the object surface.

[0042] 9 shows the lens shift process executed according to a program by the lens control unit 150. In the following description, S means step.

[0043] In S100, the lens control unit 150 displays guidance on the display unit 206, etc., to have the user adjust the position of the shift lens group in order to set the shooting composition before the composition shift. This adjustment is performed by driving the shift lens group in response to the user's operation on an operation unit provided on the camera body 200 or the lens unit 100. The lens control unit 150 also has the user select a subject to focus on. The subject to focus on is selected by the user performing a touch operation or the like on the display unit 206 on which the display image is displayed. The camera control unit 207 acquires subject distance information indicating the distance of the selected subject.

[0044] Next, in S101, the lens control unit 150 receives subject distance information of the subject selected in S100 from the camera control unit 207. Then, based on the subject distance information, the lens control unit 150 calculates the driving amount of the focus lens 105 for focusing on the selected subject. At this time, data on information regarding the amount of focus deviation for each subject distance relative to the position of the shift lens group is stored in advance in a memory, and the driving amount of the focus lens 105 is calculated from the position of the shift lens group and the subject distance information.

[0045] Next, in S102, the lens control unit 150 judges whether or not defocusing due to the tilt effect has occurred in a part of the photographing composition at the current position of the shift lens group. Specifically, the lens control unit 150 acquires the amount of object tilt corresponding to the current position of the shift lens group from the data of object tilt sensitivity stored in advance, and if the amount of object tilt exceeds a first predetermined value (0 or a value close to it), it judges that defocusing has occurred and proceeds to S103. If the amount of object tilt does not exceed the first predetermined value, it judges that defocusing has not occurred and proceeds to S105.

[0046] In S103, the lens control unit 150 drives at least one of the first and second shift lenses 102 and 103 to change its position so that the amount of object surface tilt does not exceed a first predetermined value, and then the process proceeds to S104.

[0047] There is a risk that the subject distance will change due to driving at least one of the first and second shift lenses 102 and 103 in S103, resulting in focus deviation. Therefore, in S104, the lens control unit 150 drives the focus lens 105 to focus on the selected subject (correct the focus deviation) based on the subject distance information acquired in S101. Then, the process proceeds to S105.

[0048] In S105, the lens control unit 150 accepts an input of a composition shift amount by the user.

[0049] Next, in S106, the lens control unit 150 drives the first and second shift lenses 102 and 103 so as to obtain the input composition shift amount.

[0050] Next, in S107, the lens control unit 150 judges whether or not defocusing due to the tilt effect has occurred in a part of the photographing composition due to the driving of the first and second shift lenses 102, 103 in S106. Specifically, the judgment is made in the same manner as in S102. If defocusing has occurred (the amount of object surface tilt exceeds the first predetermined value), the process proceeds to S108, and if defocusing has not occurred (the amount of object surface tilt does not exceed the first predetermined value), the process proceeds to S110.

[0051] In S108, the lens control unit 150 drives at least one of the first and second shift lenses 102 and 103 to change its position so that the amount of object surface tilt does not exceed a first predetermined value. Then, the process proceeds to S109.

[0052] There is a risk that the subject distance will change due to driving at least one of the first and second shift lenses 102 and 103 in S108, resulting in focus deviation. Therefore, in S109, the lens control unit 150 drives the focus lens 105 to focus on the selected subject based on the subject distance information acquired in S101. Then, the process proceeds to S110.

[0053] In S110, the lens control unit 150 determines whether or not the driving of each lens has been completed, and if not, waits for completion, and if completed, ends this process.

[0054] 9, a case has been described in which tilt of the object plane occurs due to driving of the shift lens group in S106, and then the tilt of the object plane is corrected in S108. In contrast to this, a position of the shift lens group where the amount of composition shift input by the user can be obtained and where the amount of object plane tilt does not exceed a first predetermined value may be calculated. Then, the shift lens group may be driven to the obtained position. That is, the shift lens group may be driven at once to a position where the amount of composition shift input by the user and the amount of object plane tilt not exceeding the first predetermined value can be obtained. Such a position may be obtained by solving simultaneous equations consisting of two equations, a functional equation indicating the sensitivity to composition shift and a functional equation indicating the sensitivity to object plane tilt.

[0055] As described above, according to this embodiment, a composition shift corresponding to the amount of composition shift input by the user can be obtained while preventing the tilt of the object plane from exceeding a first predetermined value, and the composition shift can be performed without causing the user to feel uncomfortable. EXAMPLES

[0056] Next, a description will be given of Example 2. In Example 1, attention was focused on performing a composition shift while suppressing the inclination of the object surface only in the X direction (horizontal direction) as the first direction, but in this example, a description will be given of a case where a composition shift is performed in the horizontal direction while maintaining constant the inclination of the object surface in the Y direction (vertical direction) as the second direction.

[0057] 10 shows a scene including a subject in this embodiment. In this scene, a grassland spreads horizontally from the foreground to the background, and structures (trees and buildings) exist within the grassland. The sun is also present. Here, the photographic composition is shifted horizontally while keeping both the grassland and the structures in focus.

[0058] In this embodiment, in addition to the sensitivity to a composition shift in the X direction and the sensitivity to object surface tilt used in the first embodiment, the sensitivity to a composition shift in the Y direction and the sensitivity to object surface tilt are used.

[0059] First, as a premise, data on the composition shift sensitivity and the object surface tilt sensitivity with respect to the shift amount in the X direction and the Y direction of the shift lens for each of the first and second shift lenses 102 and 103 is stored in advance in a memory in the lens control unit 150. As in the first embodiment, the stored data may be a data table or a function indicating each sensitivity.

[0060] 11(a) to (c) show how the composition is shifted to the right as shown in FIG. 11(b) and (c) from the state in which the shooting composition before the composition shift shown in FIG. 11(a) is set.

[0061] 12(a) to (c) each show a schematic diagram of the positions of the first and second shift lenses 102, 103 relative to the imaging surface of the image sensor 201 as viewed from the X direction in a state in which focus deviation caused by the inclination of the object surface is corrected when the photographing compositions shown in FIGS. 11(a) to (c) are set. In FIGS. 12(a) to (c), the lines within the first and second shift lenses 102, 103 represent the inclination of the object surface in the Y direction. The positions of the first and second shift lenses 102, 103 as viewed from the Y direction are the same as those in FIGS. 7(a) to (c).

[0062] 12(a) to (c), when performing a composition shift in the X direction from a state in which a photographing composition before a composition shift is set, the position of the shift lens group in the Y direction is held so that the amount of object face tilt in the Y direction is maintained at a value desired by the user (hereinafter referred to as a set tilt amount) or a value close to that value. That is, when the amount of change in the amount of object face tilt in the Y direction from the set tilt amount exceeds a second predetermined value (0 or a value close to that), which is an allowable value, the shift lens group is driven in the Y direction to correct the amount of change so that it does not exceed the second predetermined value. At this time, similar to the first embodiment, the shift lens group is driven in the X direction to correct the amount of object face tilt in the X direction so that it does not exceed a first predetermined value.

[0063] Fig. 13(A), (B), and (C) respectively show the time change of the position of the focus lens 105 and the first and second shift lenses 102, 103 in the X direction from the state of Fig. 11(a) and Fig. 12(a) to the state of Fig. 11(c) and Fig. 12(c). Fig. 13(D) and (E) respectively show the time change of the position of the first and second shift lenses 102, 103 in the Y direction from the state of Fig. 11(a) and Fig. 12(a) to the state of Fig. 11(c) and Fig. 12(c). (a), (b), and (c) in Fig. 13(A) to (D) respectively show the positions of the focus lens 105 and the first and second shift lenses 102, 103 in the states of Fig. 11(a) and Fig. 12(a), Fig. 11(b) and Fig. 12(b), and Fig. 11(c) and Fig. 12(c).

[0064] The change (correction) in the position of the second shift lens 103 in the X direction shown in Fig. 13(C) is the same as that shown in Fig. 8(C). In Figs. 13(D) and (E), the positions of the first and second shift lenses 102 and 103 in the Y direction are maintained.

[0065] 14 shows the lens shift process executed according to a program by the lens control unit 150. In the following description, S means step.

[0066] In S200, the lens control unit 150 displays guidance on the display unit 206, etc., to have the user adjust the position of the shift lens group in the X direction to set the shooting composition before the composition shift in the X direction. Also, the lens control unit 150 has the user adjust the position of the shift lens group in the Y direction to set the object face tilt amount in the Y direction to a value desired by the user. The shooting composition and the object face tilt amount in the Y direction are adjusted by driving the shift lens group in response to the user's operation on the operation unit provided on the camera body 200 or the lens unit 100. Furthermore, the lens control unit 150 has the user select the object to be focused on. The method of selecting the object to be focused on is the same as in the first embodiment. The camera control unit 207 acquires object distance information indicating the distance of the selected object.

[0067] Next, in S201, the lens control unit 150 receives subject distance information of the subject selected in S200 from the camera control unit 207. Then, based on the subject distance information, the lens control unit 150 calculates the driving amount of the focus lens 105 for focusing on the selected subject.

[0068] Next, in S202, the lens control unit 150 judges whether or not defocusing due to the tilt effect occurs in a part of the X-direction area in the photographing composition at the current position of the shift lens group. Specifically, the lens control unit 150 acquires the amount of object face tilt in the X-direction corresponding to the current position of the shift lens group in the X-direction from the data of the object face tilt sensitivity in the X-direction stored in advance, and if the amount of object face tilt exceeds a first predetermined value, it is judged that defocusing has occurred and proceeds to S203. If the amount of object face tilt does not exceed the first predetermined value, it is judged that defocusing has not occurred and proceeds to S205.

[0069] In S203, the lens control unit 150 drives at least one of the first and second shift lenses 102 and 103 to change its position in the X direction so that the amount of object surface tilt in the X direction does not exceed a first predetermined value. Then, the process proceeds to S204.

[0070] There is a risk that the subject distance will change due to driving at least one of the first and second shift lenses 102 and 103 in S203, resulting in focus deviation. Therefore, in S204, the lens control unit 150 drives the focus lens 105 to focus on the selected subject based on the subject distance information acquired in S201. Then, the process proceeds to S205.

[0071] In S205, the lens control unit 150 judges whether or not defocusing due to the tilt effect occurs in a part of the Y direction in the photographing composition at the current position of the shift lens group. Specifically, the lens control unit 150 acquires the amount of object face tilt in the Y direction corresponding to the current position of the shift lens group in the Y direction from the data of object face tilt sensitivity in the Y direction stored in advance. Then, if the amount of change in the amount of object face tilt from the set amount of inclination exceeds a second predetermined value, it is judged that defocusing has occurred, and the process proceeds to S206. If the amount of change does not exceed the second predetermined value, the process proceeds to S208.

[0072] In S206, the lens control unit 150 drives at least one of the first and second shift lenses 102 and 103 to change its position in the Y direction so that the change in the amount of object surface tilt in the Y direction does not exceed a second predetermined value. Then, the process proceeds to S207.

[0073] There is a risk that the subject distance will change due to driving at least one of the first and second shift lenses 102 and 103 in S206, resulting in focus deviation. Therefore, in S207, the lens control unit 150 drives the focus lens 105 to focus on the selected subject based on the subject distance information acquired in S201. Then, the process proceeds to S208.

[0074] In S208, the lens control unit 150 accepts an input of the amount of composition shift in the X direction by the user.

[0075] Next, in S209, the lens control unit 150 drives the first and second shift lenses 102 and 103 in the X direction so as to obtain the input composition shift amount.

[0076] Next, in S210, the lens control unit 150 determines whether or not defocusing due to the tilt effect has occurred in a portion of the X-direction area in the photographing composition due to the driving of the first and second shift lenses 102, 103 in S209. Specifically, the determination is made in the same manner as in S202. If defocusing has occurred (the amount of object surface tilt in the X-direction exceeds the first predetermined value), the process proceeds to S211, and if defocusing has not occurred (the amount of object surface tilt in the X-direction does not exceed the first predetermined value), the process proceeds to S216.

[0077] In S211, the lens control unit 150 drives at least one of the first and second shift lenses 102 and 103 to change its position in the X direction so that the amount of object surface tilt in the X direction does not exceed a first predetermined value. Then, the process proceeds to S212.

[0078] There is a risk that the subject distance will change due to driving at least one of the first and second shift lenses 102 and 103 in S210, resulting in focus deviation. Therefore, in S212, the lens control unit 150 drives the focus lens 105 to focus on the selected subject based on the subject distance information acquired in S201. Then, the process proceeds to S213.

[0079] In S213, the lens control unit 150 judges whether or not defocus due to the tilt effect has occurred in a part of the Y direction in the photographing composition at the current position of the shift lens group. Specifically, the judgment is made in the same manner as in S205. If defocus has occurred (the change in the amount of object surface tilt in the Y direction from the set bending amount has exceeded the second predetermined value), the process proceeds to S214, and if defocus has not occurred (the change in the amount of object surface tilt in the Y direction has not exceeded the second predetermined value), the process proceeds to S216.

[0080] In S214, the lens control unit 150 drives at least one of the first and second shift lenses 102 and 103 to change its position in the Y direction so that the amount of change in the amount of object surface tilt in the Y direction from the set amount of tilt does not exceed a second predetermined value. Then, the process proceeds to S215.

[0081] There is a risk that the subject distance will change due to driving at least one of the first and second shift lenses 102 and 103 in S214, resulting in focus deviation. Therefore, in S215, the lens control unit 150 drives the focus lens 105 to focus on the selected subject based on the subject distance information acquired in S201. Then, the process proceeds to S216.

[0082] In S216, the lens control unit 150 determines whether or not the driving of each lens is complete, and if not, waits for completion, and if completed, ends this process.

[0083] In FIG. 12, the case where the object plane tilt occurs in the X direction or the object plane tilt amount changes in the Y direction due to the driving of the shift lens group in S209, and then the tilt of the object plane is corrected in S211 or S214. In contrast to this, a position of the shift lens group where the composition shift amount input by the user is obtained and where the change amount of the object plane tilt amount in the X direction and the object plane tilt amount in the Y direction from the set tilt amount does not exceed a first predetermined value and a second predetermined value, respectively, may be calculated. Then, the shift lens group may be driven to the obtained position. That is, the shift lens group may be driven at once to a position where the composition shift amount input by the user and the change amount of the object plane tilt amount in the X direction that does not exceed the first predetermined value and the object plane tilt amount in the Y direction that does not exceed the second predetermined value are obtained. Such a position is obtained by solving a simultaneous equation consisting of four equations, two function equations indicating the composition shift sensitivity in the X direction and the Y direction, and two function equations indicating the object plane tilt sensitivity in the X direction and the Y direction.

[0084] As described above, according to this embodiment, a composition shift corresponding to the amount of composition shift input by the user can be obtained while suppressing the inclination of the object plane in the X direction so as not to exceed a first predetermined value, and while maintaining the amount of object plane inclination in the Y direction constant (set inclination amount). As a result, the composition shift can be performed without giving the user a sense of incongruity.

[0085] Although the above embodiment has been described with respect to a lens-interchangeable camera system, the same lens shift processing as in the above embodiment can also be performed with a lens-integrated camera (optical device).

[0086] The above embodiment includes the following configurations.

[0087] (Configuration 1) an imaging optical system including a first shift lens and a second shift lens that are movable in a direction perpendicular to an optical axis; a control means for controlling the driving of the first and second shift lenses so as to shift the photographing range; the control means controls the driving of the first and second shift lenses so that an amount of inclination of an object surface caused by driving the first and second shift lenses does not exceed a first predetermined value when shifting the shooting range by a target amount. (Configuration 2) 2. The optical device according to configuration 1, wherein the first predetermined value is zero. (Configuration 3) The optical device described in configuration 1 or 2, characterized in that the control means drives the first and second shift lenses to positions determined by a driving amount of the first and second shift lenses for shifting the shooting range by the target amount and a driving amount of at least one of the first and second shift lenses for preventing the amount of tilt from exceeding the first predetermined value. (Configuration 4) The optical device described in any one of configurations 1 to 3, characterized in that the control means controls driving of the first and second shift lenses using information regarding the shift amount of the shooting range corresponding to each position of the first and second shift lenses and information regarding the tilt amount of the object surface corresponding to each position of the first and second shift lenses. (Configuration 5) The optical device described in any one of configurations 1 to 4, characterized in that, when shifting the shooting range in a first direction by the target amount, the control means controls the driving of the first and second shift lenses so that the amount of inclination of the object surface in a second direction different from the first direction does not change from the set amount of inclination by more than a second predetermined value. (Configuration 6) The optical device according to configuration 5, wherein the second predetermined value is 0. (Configuration 7) The optical device described in configuration 5 or 6, characterized in that the control means controls the driving of the first and second shift lenses using information regarding the amount of inclination of the object surface according to the respective positions of the first and second shift lenses in the second direction. (Configuration 8) The photographing optical system has a focus lens, 8. The optical device according to any one of configurations 1 to 7, wherein the control means controls driving of the focus lens so as to correct focus deviation caused by driving of the first and second shift lenses. (Configuration 9) 9. The optical device according to configuration 8, wherein driving of the focus lens is controlled using information regarding the amount of focus deviation corresponding to each position of the first and second shift lenses.

[0088] (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-described 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.

[0089] The embodiments described above are merely representative examples, and various modifications and alterations are possible for each embodiment when implementing the present invention. [Explanation of symbols]

[0090] 100 Lens unit 102 1st shift lens 103 2nd shift lens 105 Focus Lens 150 Lens control unit 200 Camera body

Claims

1. an imaging optical system including a first shift lens and a second shift lens that are movable in a direction perpendicular to an optical axis; a control means for controlling the driving of the first and second shift lenses so as to shift the photographing range, the control means controls the driving of the first and second shift lenses so that an amount of inclination of an object surface caused by driving the first and second shift lenses does not exceed a first predetermined value when shifting the shooting range by a target amount.

2. 2. The optical device according to claim 1, wherein the first predetermined value is zero.

3. 2. The optical device according to claim 1, wherein the control means drives the first and second shift lenses to positions determined by a driving amount of the first and second shift lenses for shifting the shooting range by the target amount and a driving amount of at least one of the first and second shift lenses for preventing the amount of tilt from exceeding the first predetermined value.

4. 2. The optical device according to claim 1, wherein the control means controls driving of the first and second shift lenses using information on a shift amount of the shooting range corresponding to each position of the first and second shift lenses and information on a tilt amount of the object surface corresponding to each position of the first and second shift lenses.

5. 2. The optical device according to claim 1, wherein the control means controls the driving of the first and second shift lenses so that, when the shooting range is shifted in a first direction by the target amount, the amount of inclination of the object plane in a second direction different from the first direction does not change from the set amount of inclination by more than a second predetermined value.

6. 6. The optical device according to claim 5, wherein the second predetermined value is zero.

7. 6. The optical device according to claim 5, wherein the control means controls driving of the first and second shift lenses using information regarding the amount of inclination of the object surface according to the respective positions of the first and second shift lenses in the second direction.

8. The photographing optical system has a focus lens, 2. The optical device according to claim 1, wherein the control means controls the driving of the focus lens so as to correct a focus error caused by driving the first and second shift lenses.

9. 7. The optical device according to claim 6, wherein driving of the focus lens is controlled using information relating to a focus deviation amount corresponding to each of the positions of the first and second shift lenses.

10. A method for controlling an optical device having a photographing optical system including a first shift lens and a second shift lens that are movable in a direction perpendicular to an optical axis, comprising: A step of controlling driving of the first and second shift lenses so as to shift a photographing range, a control method for controlling driving of the first and second shift lenses so that, when shifting the shooting range by a target amount in this step, the amount of inclination of the object surface caused by driving the first and second shift lenses does not exceed a first predetermined value.

11. A program for causing a computer of the optical device to execute a process according to the control method of claim 10.

Images