JP2019146132A - Imaging apparatus, exposure control method, program, and recording medium - Google Patents

Abstract

To provide an imaging apparatus capable of performing exposure control under the consideration of light quantity adjustment by a light attenuating filter, even when the light attenuating filter is not mounted on a camera body.SOLUTION: The imaging apparatus includes the camera body including an imaging element and a first processing part and a lens unit including a lens for condensing light from a subject and forming an image on the imaging element and the light attenuating filter for attenuating the light quantity of the light from the subject. The camera body includes a storage part for storing first exposure control information corresponding to the lens unit including the light attenuating filter. The first processing part performs first exposure control for adjusting the light quantity of the light from the subject on the basis of the first exposure control information.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an imaging apparatus that performs exposure control, an exposure control method, a program, and a recording medium.

  2. Description of the Related Art Conventionally, an ND filter (Neutral Density Filter) is used to reduce the amount of light that reaches an image sensor of a camera body when photographing under a long exposure time or a bright light source.

  As a prior art, a video camera in which an ND filter is mounted on a camera body is known (see Patent Document 1). This video camera automatically adjusts the black balance.

  A camera in which an ND filter is mounted on a lens unit is known (see Patent Document 2). In this camera, an ND filter can be inserted into and removed from the optical axis.

  In addition, a single ND filter that can be attached to a camera body or a lens unit is known (see Patent Document 3). This ND filter may be incorporated in the camera body, may be incorporated in the lens unit, or may be detachably provided between the camera body and the lens unit.

JP 2016-187121 A JP 2016-14797 A JP 2011-70150 A (paragraph 0045)

  When the ND filter is not mounted on the camera body, the camera body does not have information on the ND filter. Therefore, it is difficult for the camera body to handle a lens unit with a built-in ND filter when performing exposure control. In the case of a lens unit with a built-in ND filter, the camera body can perform exposure control by changing the shutter speed, aperture, and gain, but it is difficult to control exposure by taking into account light quantity adjustment by the ND filter. As a result, the accuracy of exposure control may be reduced.

  In one aspect, an imaging apparatus includes a camera body having an imaging element and a first processing unit, a lens that collects light from a subject and forms an image on the imaging element, and a reduction that attenuates the amount of light from the subject. And a lens unit having a light filter. The camera body includes a storage unit that stores first exposure control information corresponding to the lens unit having the neutral density filter, and the first processing unit includes a first processing unit. Based on the exposure control information, first exposure control for adjusting the amount of light from the subject is performed.

  A lens unit may be attached to the camera body in a replaceable manner. The storage unit may hold a plurality of pieces of first exposure control information that are different for each lens unit. The first processing unit may acquire identification information of the mounted lens unit, and perform first exposure control based on first exposure control information corresponding to the identification information of the mounted lens unit.

  A lens unit may be attached to the camera body in a replaceable manner. The storage unit may store second exposure control information corresponding to a lens unit that does not have a neutral density filter. The first processing unit determines whether or not the mounted lens unit is a lens unit having a neutral density filter. If the mounted lens unit is a lens unit having a neutral density filter, the first exposure is performed. When the first exposure control is performed based on the control information and the mounted lens unit is a lens unit that does not have a neutral density filter, the amount of light from the subject is adjusted based on the second exposure control information. Second exposure control may be performed.

  The first exposure control information may include control information for an aperture value, a shutter speed, a gain for amplifying an image signal obtained by the image sensor, and a dimming degree by the neutral density filter.

  The second exposure control information may include control information for an aperture value, a shutter speed, and a gain for amplifying an image signal obtained by the image sensor.

  The lens unit may include a second processing unit. The first processing unit may send information on an exposure control instruction value for performing at least a part of the first exposure control in the lens unit to the lens unit. The second processing unit may acquire information on the exposure control instruction value, and determine an aperture value and a dimming degree by the neutral density filter based on the exposure control instruction value.

  The lens unit may include a second processing unit. When changing the exposure control instruction value, the second processing unit may change the aperture value while fixing the dimming degree.

  The lens unit may include a second processing unit. When changing the exposure control instruction value, the second processing unit may change the light attenuation by fixing the aperture value.

  The lens unit may include a second processing unit. The second processing unit, when changing the exposure control instruction value, a first change process for fixing the dimming degree and changing the aperture value, and a second changing process for changing the dimming degree by fixing the aperture value. And may be repeated.

  In one aspect, the exposure control method is an exposure control method in an imaging apparatus including a camera body having an image sensor and a lens unit, and the lens unit collects light from a subject and connects the light to the image sensor. An image lens and a neutral density filter that attenuates the amount of light from the subject, and the camera body includes a storage unit that stores first exposure control information corresponding to the lens unit having the neutral density filter, Performing a first exposure control for adjusting the amount of light from the subject based on the first exposure control information.

  The storage unit may hold a plurality of pieces of first exposure control information that are different for each lens unit. The step of performing the first exposure control includes a step of acquiring identification information of the lens unit attached to the camera body and a first exposure control information corresponding to the identification information of the attached lens unit. Performing the exposure control.

  The storage unit may store second exposure control information corresponding to a lens unit that does not have a neutral density filter. The step of performing the first exposure control includes the step of determining whether or not the lens unit mounted on the camera body is a lens unit having a neutral density filter, and the lens unit in which the mounted lens unit has a neutral density filter. In this case, a step of performing first exposure control based on the first control information may be included. In the exposure control method, when the mounted lens unit is a lens unit that does not have a neutral density filter, a step of performing second exposure control that adjusts the amount of light from the subject based on the second exposure control information. , May further be included.

  The first exposure control information may include control information for an aperture value, a shutter speed, a gain for amplifying an image signal obtained by the image sensor, and a dimming degree by the neutral density filter.

  The second exposure control information may include control information for an aperture value, a shutter speed, and a gain for amplifying an image signal obtained by the image sensor.

  In the exposure control method, in the camera body, the step of sending exposure control instruction value information for performing at least part of the first exposure control in the lens unit to the lens unit, and the information of the exposure control instruction value in the lens unit And a step of determining an aperture value and a dimming degree by the neutral density filter based on the exposure control instruction value in the lens unit.

  The step of determining the aperture value and the dimming level by the neutral density filter may include a step of changing the aperture value while fixing the dimming level when changing the exposure control instruction value.

  The step of determining the aperture value and the dimming degree by the neutral density filter may include a step of changing the dimming level while fixing the aperture value when changing the exposure control instruction value.

  The step of determining the aperture value and the dimming degree by the neutral density filter includes the first change process for changing the aperture value by fixing the dimming level and the aperture value being fixed when the exposure control instruction value is changed. Repetitively performing a second changing process for changing the luminous intensity.

  In one aspect, the program includes a camera body having an image sensor, a lens unit that collects light from the subject and forms an image on the image sensor, and a lens unit that attenuates the amount of light from the subject; For performing the first exposure control for adjusting the amount of light from the subject based on the first exposure control information corresponding to the lens unit having the neutral density filter. It is a program.

  In one aspect, the recording medium includes a camera body having an image sensor, a lens that collects light from the subject and forms an image on the image sensor, and a neutral density filter that attenuates the amount of light from the subject. And a step of performing first exposure control for adjusting the amount of light from the subject based on first exposure control information corresponding to a lens unit having a neutral density filter. This is a computer-readable recording medium on which the program is recorded.

  Note that the summary of the invention described above does not enumerate all the features of the present disclosure. In addition, a sub-combination of these feature groups can also be an invention.

The figure which shows the hardware constitutions of the camera in 1st Embodiment. The figure which shows the electronic contact of a camera body and a lens unit Flow chart showing exposure control procedure by imaging apparatus Sequence diagram showing a first example of registration procedure of exposure control information Sequence diagram showing a second example of registration procedure of exposure control information Sequence diagram showing exposure control procedure using exposure control information The figure which shows the 1st example of the exposure control in a lens unit The figure which shows the 2nd example of the exposure control in a lens unit. The figure which shows the 3rd example of exposure control in a lens unit.

  Hereinafter, although this indication is explained through an embodiment of the invention, the following embodiment does not limit the invention concerning a claim. Not all combinations of features described in the embodiments are essential for the solution of the invention.

  The claims, the description, the drawings, and the abstract include matters subject to copyright protection. The copyright owner will not object to any number of copies of these documents as they appear in the JPO file or record. However, in other cases, all copyrights are reserved.

  An imaging apparatus according to the following embodiment is a camera in which a replaceable lens unit is mounted on a camera body. When the interchangeable lens unit is mounted, the camera body determines whether or not there is an ND filter built in the lens unit when it can communicate with the lens unit. In the present embodiment, a case where an ND filter is mainly incorporated in the lens unit is exemplified, but it may not be incorporated.

(First embodiment)
FIG. 1 is a diagram illustrating a hardware configuration of the imaging device 5 according to the first embodiment. The imaging device 5 has a configuration including a camera body 10 and a replaceable lens unit 30. The imaging device 5 is an example of an imaging device. The camera body 10 includes a camera processor 11, a shutter 12, an imaging device 13, an image processing unit 14, a memory 15, a display unit 16, an operation unit 17, a shutter driving unit 19, an element driving unit 20, a gain control unit 21, and a signal interface. (I / F) 18.

  The camera processor 11 (an example of a first processing unit) determines shooting conditions such as exposure time and aperture (iris). The camera processor 11 performs exposure (AE: Automatic Exposure) control in consideration of the light attenuation by the ND filter. For example, when the light is attenuated by one stage by the ND filter, the camera processor 11 may set the shutter speed to half and maintain a proper exposure. The camera processor 11 may calculate a luminance level (for example, a pixel value) from the image data output from the image processing unit 14. The camera processor 11 may calculate a gain value for the image sensor 13 based on the calculated luminance level, and send the calculation result to the gain control unit 21. The camera processor 11 may calculate a shutter speed value for opening and closing the shutter 12 based on the calculated luminance level, and send the calculation result to the shutter drive unit 19. The camera processor 11 may send an imaging instruction to the element driving unit 20 that supplies a timing signal to the imaging element 13. The camera processor 11 is an example of a first processing unit.

  The shutter 12 is a focal plane shutter, for example, and is driven by a shutter drive unit 19. The incident light when the shutter 12 is opened forms an image on the imaging surface of the image sensor 13. The image sensor 13 photoelectrically converts an optical image formed on the imaging surface and outputs it as an image signal. As the imaging device 13, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor may be used.

  The gain control unit 21 reduces noise with respect to the image signal input from the image sensor 13 and controls a gain (gain) for amplifying the image signal.

  The image processing unit 14 performs analog-digital conversion on the imaging signal amplified by the gain control unit 21 to generate image data. The image processing unit 14 may perform various processes such as shading correction, color correction, contour enhancement, noise removal, gamma correction, debayering, and compression.

  The memory 15 is a storage medium that stores various data and image data. In the memory 15, lens unit information regarding the lens unit 30 is registered. The lens unit information includes, for example, information on a lens ID for identifying a lens included in the lens unit 30, information on whether or not the lens unit 30 has an ND filter 32, and a dimming degree (ND value) of the ND filter 32 is variable. Information on whether or not, and information on the control range of the ND value. The type of the lens unit 30 can be distinguished from the lens ID, for example. The types of the lens unit 30 may include, for example, a telephoto lens, a standard lens, a macro lens, and the like.

  The memory 15 (an example of a storage unit) may hold information on a function f (x) for calculating the exposure amount E based on, for example, the shutter speed S, F value, and ISO sensitivity. In this case, the memory 15 may register and hold information on the function f (x) for each lens unit 30 or for each type of lens unit 30. For example, the memory 15 may hold information on a function f ′ (x) for calculating the exposure amount E based on the shutter speed S, F value, ISO sensitivity, and ND value. In this case, the memory 15 may register and hold information on the function f ′ (x) for each lens unit 30 or each type of lens unit 30. The memory 15 may hold information on the shutter speed S, F value, and ISO sensitivity (gain) being set, for example.

  The function f ′ (x) is an example of the exposure control information EC1, and is an example of the first exposure control information. The function f ′ (x) is an example of exposure control information EC2, and is an example of second exposure control information. The ISO sensitivity is a value corresponding to the gain. The ND value represents the dimming degree by the neutral density filter.

  That is, the memory 15 may hold the exposure control information EC1 corresponding to the lens unit 30 having the ND filter 32. The memory 15 may hold exposure control information EC2 corresponding to the lens unit 30 that does not have the ND filter 32. The memory 15 may hold a plurality of exposure control information EC1 that are different for each lens unit 30. The memory 15 may hold a plurality of exposure control information EC2 different for each lens unit 30.

  The camera processor 11 may perform exposure control according to the exposure control information EC1 or the exposure control information EC2. The exposure control according to the exposure control information EC1 is an example of first exposure control. The exposure control according to the exposure control information EC2 is an example of second exposure control. Note that the exposure control by the camera processor 11 may include adjusting the values of parameters related to the camera body 10 and performing exposure control. The exposure control by the camera processor 11 may include the camera body 10 sending an instruction related to the exposure control in the lens unit 30 to the lens unit 30 and the lens unit 39 performing the exposure control according to this instruction.

  The display unit 16 includes a monitor and a finder, and may display an image that has been subjected to image processing by the image processing unit 14. The display unit 16 may display setting information related to various settings of the imaging device 5. The image may be a still image or a moving image.

  The operation unit 17 may include a rotary switch, a power switch, a mode selection switch, and the like for switching an imaging mode (for example, a shutter speed priority mode and an aperture priority mode) in addition to the release SW 17z. The operation unit 17 may include various keys, buttons, a touch panel, and the like.

  The shutter drive unit 19 opens and closes the shutter 12 at the shutter speed instructed from the camera processor 11. The element driving unit 20 is a timing generator, supplies a timing signal to the image sensor 13 in accordance with an imaging instruction from the camera processor 11, and performs a charge accumulation operation, a read operation, a reset operation, and the like of the image sensor 13.

  The signal I / F 18 communicates with the signal I / F 35 of the lens unit 30. For example, the signal I / F 18 may transmit a focus drive command to the lens unit 30. The signal I / F 18 may communicate information on the operating state of the camera body 10 and the lens unit 30, optical information, instruction information, and other information.

  The lens unit 30 is an interchangeable lens, and is detachably attached to the mount 25 (see FIG. 2) of the camera body 10. The lens unit 30 includes a lens processor 31, an ND filter 32, a diaphragm 33, a lens group 34, and a signal interface (I / F) 35. The lens unit 30 includes a lens driving unit 36, an ND driving unit 38, and an aperture driving unit 40. The lens unit 30 may not be an interchangeable lens.

  The lens processor 31 (an example of a second processing unit) controls each unit of the lens unit 30. For example, when the lens processor 31 receives a signal from the camera processor 11 via the signal I / F 35, the lens processor 31 may be activated to be able to communicate with the camera processor 11. The lens processor 31 may control each unit such as the lens group 34, the diaphragm 33, and the ND filter 32 in accordance with an instruction from the camera processor 11. The lens group 34 may include one or more lenses.

  The memory 37 holds various data and information. The memory 37 may include a memory 31z that holds information regarding the lens unit 30 (lens unit information). Information on the lens unit 30 includes information for identifying the lens group 34 (for example, a lens ID), information on the ND filter 32 in the lens unit 30 (for example, information on the presence / absence of the ND filter 32), and information on the diaphragm 33 in the lens unit 30. (For example, information on presence / absence of aperture) may be included. The memory 37 may hold information on the F value and ND value being set in the lens unit 30, for example.

  The signal I / F 35 communicates with the signal I / F 18 of the camera processor 11.

  The lens group 34 collects light from the subject and forms an image on the image sensor 13. The lens group 34 includes a focus lens, a zoom lens, an image blur correction lens, and the like. The lens group 34 is driven by a lens driving unit 36. The lens driving unit 36 includes a motor (not shown), and when a control signal from the lens processor 31 is input, the lens group 34 including the focus lens may be moved in the direction of the optical axis op (optical axis direction). .

  The diaphragm 33 is driven by the diaphragm driver 40. The aperture driving unit 40 includes a motor (not shown), and when the control signal from the lens processor 31 is input, the aperture of the aperture 33 is enlarged or reduced.

  The ND filter 32 is disposed, for example, in the vicinity of the diaphragm 33 in the direction of the optical axis op (optical axis direction), and performs dimming to limit the amount of incident light. That is, the ND filter 32 attenuates the amount of light from the subject. The ND filter 32 is an example of a neutral density filter. The ND filter 32 is driven by the ND drive unit 38. The ND drive unit 38 includes a motor (not shown), and when the control signal from the lens processor 31 is input, the ND filter 32 may be inserted into and removed from the optical axis op. Whether or not the ND filter 32 is inserted on the optical axis op can be determined using, for example, a photo interrupter that blocks light when the ND filter 32 is inserted and passes light when the ND filter 32 is removed. is there. Further, the lens unit 30 may be provided with a light amount sensor or the like, and the light amount sensor or the like may determine the dimming degree according to the light blocking condition, and may be sent to the lens processor 31 or the like for use in various processes. Further, the ND filter 32 may electronically adjust the ND value (dimming level), and may adjust the ND value stepwise between a state where all light is transmitted and a state where all light is blocked. .

  1 illustrates that the lens unit 30 has the diaphragm 33, the camera body 10 may have the diaphragm 33.

  FIG. 2 is a view showing the electronic contacts of the camera body 10 and the lens unit 30. A plurality of electronic contacts 27 are arranged on the front surface of the mount 25 to which the lens unit 30 is attached of the camera body 10. The plurality of electronic contacts 27 may function as a signal I / F 18 for the camera body 10 to communicate with the lens unit 30.

  A plurality of electronic contacts 47 are disposed on the front surface of the mount 45 attached to the camera body 10 of the lens unit 30. The plurality of electronic contacts 47 may function as a signal I / F 35 through which the lens unit 30 communicates with the camera body 10.

  When the lens unit 30 is attached to the camera body 10, the mount 45 and the mount 25 are brought into contact with each other, and the plurality of electronic contacts 27 and 47 are brought into contact with each other to be conducted. This enables communication between the camera body 10 and the lens unit 30 via the signal I / Fs 18 and 35. For example, when the lens unit 30 is attached to the camera body 10, identification information (for example, a lens ID) of the lens unit 30 or lens unit information regarding the lens unit 30 may be sent from the lens unit 30 to the camera body 10.

Next, the exposure control operation of the imaging device 5 will be described.
FIG. 3 is a flowchart showing an exposure control procedure of the imaging apparatus 5.

  First, the camera processor 11 determines whether or not the lens unit 30 is connected (attached) to the camera body 10 (S1).

  The connection detection of the lens unit 30 is performed, for example, in the following procedure. The camera processor 11 transmits a specific signal to the lens unit 30 through the signal I / F 18. When the lens processor 31 receives the specific signal through the signal I / F 35, the lens processor 31 returns a confirmation signal indicating that it has been received to the camera body 10. Upon receiving this confirmation signal, the camera processor 11 determines that the lens unit 30 is attached to the camera body 10. The detection of the connection of the lens unit is not limited to the communication described above, and may be determined based on whether or not the camera body 10 and the lens unit 30 are merely electrically connected. Further, when the lens unit 30 is mounted on the housing 10z of the camera body 10, the detection of the connection of the lens unit may be determined using an operating mechanical switch. Further, the detection of the connection of the lens unit may be determined using a photosensor provided in the housing 10z of the camera body 10 and detecting a light amount difference depending on the presence or absence of the lens unit 30.

  When the lens unit 30 is not connected to the camera body 10, the camera processor 11 repeats the process of S1.

  When the lens unit 30 is connected to the camera body 10 in S1, the camera processor 11 identifies the type of the lens unit 30 (S2). The type of the lens unit is identified by, for example, receiving lens unit information transmitted from the lens processor 31 through the signal I / F 35 by the camera body 10 and identifying the lens unit information by the camera processor 11. Good. The lens unit information may include at least a lens ID and information indicating the presence / absence of the ND filter 32.

  The camera processor 11 determines whether or not the ND filter 32 is mounted (built in) the lens unit 30 based on the lens unit information (S3).

  When the ND filter 32 is not mounted on the lens unit 30, the camera processor 11 selects exposure control information EC2 for controlling exposure without using the ND filter 32, and performs exposure control according to the exposure control information EC2 (S4). . The exposure control that does not use the ND filter 32 will be described later. The exposure control information EC2 may be held in the memory 15 before the exposure control is performed.

  When the ND filter 32 is mounted on the lens unit 30, the camera processor 11 selects exposure control information EC1 for exposure control using the ND filter 32, and performs exposure control according to the exposure control information EC1 (S5). The exposure control information EC1 may be held in the memory 15 before the exposure control is performed. After the processes of S4 and S5, the camera processor 11 ends the main exposure control.

  Thus, the camera processor 11 may determine whether or not the mounted lens unit 30 is a lens unit having the ND filter 32. When the attached lens unit is the lens unit 30 having the ND filter 32, the camera processor 11 may perform the first exposure control based on the exposure control information EC1. When the attached lens unit is a lens unit that does not have the ND filter 32, the camera processor 11 may perform exposure control based on the exposure control information EC2.

  According to such an exposure control procedure, the imaging device 5 can determine whether or not the lens unit 30 connected to the camera body 10 has the ND filter 32, and can change the exposure control method according to the determination result. . Specifically, it is possible to change parameters to be added in exposure control. For example, when the lens unit 30 includes the ND filter 32, the imaging device 5 can perform exposure control in consideration of information on the ND value of the ND filter 32 that is a parameter related to the ND filter 32. Therefore, when the lens unit 30 has the ND filter 32, the imaging device 5 can perform exposure control in consideration of the light attenuation by the ND filter 32, and when the lens unit 30 does not have the ND filter 32, Exposure control can be performed without taking into account the light attenuation by the filter 32.

  Next, a procedure for generating the exposure control information EC1 and EC2 will be described.

  The generation of the exposure control information EC1 and EC2 is performed, for example, when the lens unit 30 is attached to the camera body 10 for the first time. Therefore, when the same lens unit 30 is mounted for the second time, the generation of the exposure control information EC1 and EC2 is omitted, and the exposure control is performed based on the already registered exposure control information EC1 and EC2. Good. The generated exposure control information EC1, EC2 is registered in the memory 15.

  FIG. 4 is a sequence diagram illustrating a first generation example of the exposure control information EC1 and EC2 by the imaging device 5.

  When the lens unit 30 is attached to the camera body 10, the camera body 10 receives lens unit information (for example, lens ID, presence / absence of the ND filter 32, whether the ND filter 32 is ON / OFF, the ND value). (Information such as control range) is received (T0). The camera processor 11 holds the lens unit information received from the lens unit 30 in the memory 15.

  In order to generate the exposure control information EC1 and EC2 by the imaging device 5, the user sets an arbitrary subject (for example, a whiteboard) irradiated with arbitrary light (for example, ambient light) as the subject (T1).

  And the camera processor 11 implements procedure T3-T7, when the mounted lens unit 30 does not have the ND filter 32, ie, when the information regarding the ND filter 32 is not contained in lens unit information. When the attached lens unit 30 has the ND filter 32, that is, when the lens unit information includes information related to the ND filter 32, the camera processor 11 performs steps T3A to T7A.

  The camera processor 11 sets three parameters when the information regarding the ND filter 32 is not included in the lens unit information (T3). The three parameters here are an aperture value (F value), a shutter speed (S), and a gain (ISO sensitivity). These values are values set in the camera body 10 as arbitrary values. For example, the three parameters are set to F: 1.8, S: 1/60, and ISO: 100. As these three parameters, values arbitrarily input by the user via the operation unit 17 of the camera body 10 may be used. The set values of the three parameters may be held in the memory 15.

  The camera processor 11 captures an image of the subject via the image sensor 13 under the image capturing conditions in which three parameters are set (T4). The camera processor 11 calculates the average luminance based on the luminance of each pixel of the image sensor 13 obtained by this imaging, and obtains the exposure amount E1 based on the average luminance (T5). Information on the exposure amount E1 may be held in the memory 15. The luminance of each pixel may be indicated by a pixel value of 0 to 255, for example.

  The camera processor 11 derives the relationship between the three parameters (F value, S, ISO sensitivity) and the exposure amount E1. For example, the camera processor 11 derives (for example, calculates) a function f (x) that obtains an exposure amount E1 using three parameters (F value, S, ISO sensitivity) as variables (T6). Here, x represents the values of three parameters. For example, the three parameters and the exposure amount E1 may be linear or nonlinear, and the camera processor 11 may derive the function f (x) based on one or a plurality of three parameter patterns (combinations). .

  The function f (x) defines an exposure control method for performing exposure control using three parameters of aperture value (F value), shutter speed (S), and gain (ISO sensitivity). That is, the function f (x) is an example of exposure control information EC2 using three parameters. The exposure control information EC2 may be used when the lens unit 30 that does not have the ND filter 32 is attached and exposure control is performed.

  The camera processor 11 registers the information of the derived function f (x) in the memory 15 in association with the lens unit information (for example, lens ID) (T7).

  In addition, when the lens unit information includes information regarding the ND filter 32, the camera processor 11 sets four parameters (T3A). The four parameters here are the aperture value (F value), shutter speed (S), gain (ISO sensitivity), and ND value. The ND value may be acquired from the lens unit information acquired by the camera body 10. The aperture value (F value), shutter speed (S), and gain (ISO sensitivity) are values set in the camera body 10 as arbitrary values. For example, the four parameters are set to F: 1.8, S: 1/15, ISO: 200, and ND: 1. As parameters for the aperture value (F value), shutter speed (S), and gain (ISO sensitivity), values arbitrarily input by the user via the operation unit 17 of the camera body 10 may be used. The set values of the four parameters may be held in the memory 15.

  The camera processor 11 captures an image of the subject via the image sensor 13 under the image capturing conditions in which four parameters are set (T4A). The camera processor 11 calculates the average luminance based on the luminance of each pixel of the image sensor 13 obtained by this imaging, and obtains the exposure amount E1A based on the average luminance (T5A). Information on the exposure amount E1A may be held in the memory 15. The luminance of each pixel may be indicated by a pixel value of 0 to 255, for example.

  The camera processor 11 derives the relationship between the four parameters (F value, S, ISO sensitivity, ND value) and the exposure amount E1A. For example, the camera processor 11 derives (for example, calculates) a function f ′ (x) that obtains the exposure amount E1A using four parameters (F value, S, ISO sensitivity, and ND value) as variables (T6A). Here, x represents the values of four parameters. For example, the four parameters and the exposure amount E1A are linear or non-linear, and the camera processor 11 derives the function f ′ (x) based on one or a plurality of four parameter patterns (combinations). Good.

  The function f ′ (x) defines an exposure control method for performing exposure control using four parameters of aperture value (F value), shutter speed (S), gain (ISO sensitivity), and light attenuation (ND value). To do. That is, the function f ′ (x) is an example of exposure control information EC1 using four parameters. The exposure control information EC2 may be used when the lens unit 30 having the ND filter 32 is attached and exposure control is performed.

  The camera processor 11 registers the derived function f ′ (x) information in the memory 15 in association with lens unit information (for example, lens ID) (T7A). In this way, the exposure control information EC1 when the ND filter 32 is used and the exposure control information EC2 when the ND filter 32 is not used are registered. Note that the case where the ND filter 32 is not used is not assumed, and the exposure control information EC2 when the ND filter 32 is not used may not be registered.

  According to the first generation example of such exposure control information EC1 and EC2, the imaging device 5 captures an image by arbitrarily setting parameters other than the parameter (ND value) related to the ND filter 32, and the captured image Based on the luminance and pixel values, the optical characteristics of the imaging device 5 are taken into account, and an exposure control method (for example, f (x)) suitable for the optical characteristics can be derived. The imaging device 5 captures an image by arbitrarily setting parameters including a parameter (ND value) relating to the ND filter 32, and based on the luminance and pixel value of the captured image, the imaging device 5 has an optical function. In consideration of the characteristics, an exposure control method (for example, f ′ (x)) suitable for the optical characteristics can be derived. Therefore, even when the ND filter 32 is built in the lens unit 30 and the camera body 10 does not have the parameter information of the ND filter 32, the camera body 10 holds the exposure control information EC1 to capture the image. The apparatus 5 can easily perform exposure control in consideration of the dimming amount of the ND filter 32. Even when the ND filter 32 is not built in the lens unit 30, the image capturing apparatus 5 can easily perform exposure control without taking the ND filter 32 into account by holding the exposure control information EC <b> 2 in the camera body 10. Can be implemented.

  FIG. 5 is a sequence diagram showing a second generation example of the exposure control information by the imaging device 5. In FIG. 4, it is assumed that the lens unit information shown in FIG. 4 is not sent from the lens unit 30 to the camera body 10 and the exposure control information is generated. In FIG. 5, the same procedure numbers as those shown in FIG. 4 are indicated by the same procedure numbers, and the description thereof is omitted or simplified.

  First, since lens unit information is not sent from the lens unit 30 to the camera body 10, the procedure T0 shown in FIG. 4 is omitted.

  The camera processor 11 sets the ND filter 32 to ND off (ND value = 0) for the lens unit 30 (T2). The ND off information may be held in the memory 15. When the lens unit 30 does not include the ND filter 32, the camera processor 11 does not have to do anything in step T2. Thereby, the dimming process by the ND filter 32 is not performed.

  “ND off” is a state in which the ND filter 32 does not substantially act and light does not attenuate before and after the light passes through the ND filter 32. “ND ON” is a state in which the ND filter 32 substantially operates, and indicates that the light is attenuated at least partially before and after passing through the ND filter 32. The amount of light attenuation can vary depending on the ND value.

  Then, the camera body 10 performs steps T3 to T6.

  When the exposure control information EC2 is generated, the camera processor 11 sets the ND filter 32 to ND on (ND value is an arbitrary value) for the lens unit 30. The ND value may be held in the memory 37.

  The camera processor 11 transmits the three parameters (F value, S, ISO sensitivity) obtained in T3 and information on the function f (x) derived in T6 via the signal I / F 18 to the lens unit 30. (T11).

In the lens unit 30, the lens processor 31 acquires information on these three parameters (F value, S, ISO sensitivity) and the function f (x) via the signal I / F 35. The lens processor 31 calculates the exposure amount E1 obtained in T5 based on the acquired three parameters (F value, S, ISO sensitivity) and the inverse function f ⁻¹ (x) of the function f (x). Calculation (back calculation) is performed (T12). Thereby, the lens unit 30 can grasp the exposure amount E1 without directly acquiring the exposure amount E1.

  The lens processor 31 derives the relationship between the four parameters (F value, S, ISO sensitivity, ND value) and the exposure amount E1. This ND value may be acquired from the memory 37. For example, the camera processor 11 derives (for example, calculates) a function f ′ (x) that obtains the exposure amount E1 using four parameters (F value, S, ISO sensitivity, and ND value) as variables (T13). Here, x represents the values of four parameters. For example, the four parameters and the exposure amount E1 are linear or nonlinear, and the lens processor 31 derives a function f ′ (x) based on one or a plurality of four parameter patterns (combinations). Good.

  The lens processor 31 sends information on the function f ′ (x) to the camera body 10 via the signal I / F 35 (T14). In the camera body 10, the camera processor 11 receives information on the function f ′ (x) via the signal I / F 18.

  The camera processor 11 registers the information on the derived function f (x) in the memory 15 in association with the lens unit information (T15). The camera processor 11 registers the information of the derived function f ′ (x) in the memory 15 in association with the lens unit information (for example, lens ID) (T15). In this way, the exposure control information EC1 when the ND filter 32 is used and the exposure control information EC2 when the ND filter 32 is not used are registered. Note that the case where the ND filter 32 is not used is not assumed, and the exposure control information EC2 when the ND filter 32 is not used may not be registered.

  According to the second generation example of the exposure control information EC1 and EC2, the imaging device 5 captures an image by arbitrarily setting parameters other than the parameter (ND value) related to the ND filter 32. Based on the luminance and pixel values, the optical characteristics of the imaging device 5 are taken into account, and an exposure control method (for example, f (x)) suitable for the optical characteristics can be derived. In addition, the imaging device 5 takes into account the optical characteristics when the ND filter 32 is added based on this exposure control method (for example, f (x)), and an exposure control method (for example, suitable for the optical characteristics). f ′ (x)) can be derived. Therefore, even when the ND filter 32 is built in the lens unit 30 and the camera body 10 does not have information on the parameters of the ND filter 32, the camera body 10 holds the exposure control information EC1 and EC2. The imaging device 5 can easily perform exposure control in consideration of the dimming amount of the ND filter 32. Even when the lens unit 30 does not include the ND filter 32, the image pickup apparatus 5 can easily perform exposure control that does not take the ND filter 32 into account by holding the exposure control information EC <b> 1 in the camera body 10. Can be implemented.

  In addition, in both the first generation example and the second generation example of the exposure control information EC1 and EC2, by registering the exposure control information EC1 and EC2 in advance before the exposure control, the imaging device 5 can When the lens unit 30 is attached to the camera body 10 for actual imaging, the exposure control information EC1 and EC2 can be acquired immediately. Therefore, the imaging device 5 can shorten the time required from the mounting of the lens unit 30 to the camera body 10 to the completion of exposure control.

  Next, exposure control using the exposure control information EC1 and EC2 will be described.

FIG. 6 is a sequence diagram showing an exposure control procedure using the exposure control information EC1 and EC2.
First, the camera processor 11 sets a desired exposure amount E2 (T21). The desired exposure amount E2 may be, for example, an exposure amount held in the memory 15, an exposure amount received by a user operation via the operation unit 17, or a Tv (Time Value) derived in the shutter speed priority mode. An exposure amount based on an Av (Aperture Value) value derived in the value or aperture priority mode may be used.

  When the lens unit 30 attached to the camera body 10 is equipped with the ND filter 32, the camera processor 11 uses the function f ′ (x) held in the memory 15 to correspond to the four exposure amounts E 2. Parameters (F value, S, ISO sensitivity, ND value) are derived (for example, calculated) (T22). As an example, the derived four parameters are F: 1.8, S: 1/15, ISO: 200, ND: 1.

  The camera processor 11 sends information on the F value and the ND value among the four parameters (F value, shutter speed, ISO, and ND value) to the lens unit 30 via the signal I / F 18 (T23). In the lens unit 30, the lens processor 31 receives information on the F value and the ND value via the signal I / F 35. Note that Av value information may be sent instead of specific information on the F value and the ND value. The Av value is an instruction value (lens exposure control instruction value) for exposure control in the lens unit 30. The lens processor 31 may calculate the F value and the ND value based on the Av value. The lens exposure control instruction value is an example of an exposure control instruction value.

  The camera processor 11 sets values of the shutter speed S and gain (ISO sensitivity) among the four parameters (F value, shutter speed, ISO, ND value), and holds these set values in the memory 15 (T24). ). The camera processor 11 performs exposure control using the set shutter speed S and gain (ISO sensitivity) values (T26). Accordingly, the camera processor 11 can cause the image sensor 13 to capture an image based on the set shutter speed S and gain (ISO sensitivity).

  The lens processor 31 sets the received F value and ND value, and stores these setting values in the memory 37 (T25). The lens processor 31 performs exposure control using the set F value and ND value (T26). Thereby, the lens unit 30 can adjust the exposure amount at the time of imaging by the imaging device 13 based on the set F value and ND value.

  On the other hand, when the lens unit 30 attached to the camera body 10 does not include the ND filter 32, the camera processor 11 determines 3 corresponding to the exposure amount E2 based on the function f (x) held in the memory 15. Two parameters (F value, S, ISO sensitivity) are derived (for example, calculated) (T27). As an example, the derived three parameters are F: 1.8, S: 1/30, and ISO: 200.

  The camera processor 11 sends information on the F value of the three parameters (F value, shutter speed, ISO) to the lens unit 30 via the signal I / F 18 (T28). In the lens unit 30, the lens processor 31 receives F value information via the signal I / F 35.

  The camera processor 11 sets shutter speed S and gain (ISO sensitivity) values among the three parameters (F value, shutter speed, ISO), and holds these set values in the memory 15 (T29). The lens processor 31 performs exposure control using the set shutter speed S and gain (ISO sensitivity) (T31). Accordingly, the camera processor 11 can cause the image sensor 13 to capture an image based on the set shutter speed S and gain (ISO sensitivity).

  The lens processor 31 sets the received F value, and stores this set value in the memory 37 (T30). The lens processor 31 performs exposure control using the set F value (T31). Thereby, the lens unit 30 can adjust the exposure amount at the time of imaging by the imaging device 13 based on the set F value.

  As described above, the imaging device 5 performs the exposure control using the exposure control information EC1 even when the ND filter 32 is not mounted on the camera body 10 and the ND filter 32 is mounted on the lens unit 30, for example. As a result, exposure control can be performed in consideration of light amount adjustment by the ND filter 32. For example, when the memory unit 15 holds the exposure control information EC1 in consideration of the ND filter 32 in advance, when the lens unit 30 equipped with the ND filter 32 is connected to the camera body 10, the imaging device 5 The exposure control information EC1 can be acquired from the memory 15, and the exposure control according to the exposure control information EC1 can be performed. Therefore, the imaging device 5 can perform exposure control by effectively using the ND filter 32 mounted on the lens unit 30. Even when the ND filter 32 is not mounted on the imaging device 5, exposure control can be performed without taking into account light amount adjustment by the ND filter 32 by performing exposure control using the exposure control information EC2.

  Further, the camera processor 11 may acquire identification information of the mounted lens unit 30 and perform exposure control based on the exposure control information EC1 corresponding to the identification information of the mounted lens unit.

  Therefore, even if the lens unit 30 attached to the camera body 10 is replaceable, the imaging device 5 identifies the lens unit 30 attached to the camera body 10 and an exposure control method suitable for the lens unit 30. Thus, exposure control can be performed. In addition, the imaging apparatus 5 can perform exposure control corresponding to a plurality of types of lens units 30 having the ND filter 32 by holding exposure control information EC1 corresponding to a plurality of types of lens units 30. In addition, the imaging device 5 can perform exposure control corresponding to a plurality of types of lens units 30 that do not have the ND filter 32 by holding exposure control information EC2 corresponding to a plurality of types of lens units 30.

  Further, when the lens unit 30 includes the ND filter 32, the imaging device 5 can perform exposure control using four parameters obtained by the function f ′ (x) as the exposure control information EC1. When the lens unit 30 does not include the ND filter 32, the imaging device 5 can perform exposure control using three parameters obtained by the function f (x) as the exposure control information EC2.

  In this way, the imaging device 5 can perform exposure control regardless of whether or not the ND filter 32 is present. Therefore, even if various lens units 30 are mounted, exposure control can be performed using the exposure control information EC1 and EC2 suitable for the mounted lens unit 30. Therefore, even if the lens unit 30 mounted on the camera body 10 is replaced, the exposure control state automatically adapted to the lens unit 30 after replacement is automatically obtained, and it is not necessary for the user to adjust the exposure control. Convenience is improved.

  Further, since the exposure control information EC1 is control information including the aperture value (F value), shutter speed S, ISO sensitivity, and ND value, the lens unit 30 that does not have the ND filter 32 is added to the camera body 10. Even if connected, it is possible to achieve a desired exposure amount while adjusting the balance of the light amount adjustment by the aperture value (F value), shutter speed S, ISO sensitivity, and ND value.

  In addition, since the exposure control information EC2 is control information including the aperture value (F value), the shutter speed S, and the ISO sensitivity, the lens unit 30 that does not have the ND filter 32 is connected to the camera body 10. In addition, it is possible to realize a desired exposure amount while adjusting the balance of the light amount adjustment by the aperture value (F value), shutter speed S, and ISO sensitivity.

  Next, a specific example of exposure control will be described.

  Here, the exposure control in the lens unit 30 will be mainly described. Further, it is assumed that the camera body 10 instructs the lens unit 30 to specify the Av value in the aperture priority mode, and the lens unit 30 determines the F value and the ND value based on the Av value. The smaller the Av value, the greater the amount of light that reaches the camera body 10 and the brighter it becomes. The larger the Av value, the less the amount of light that reaches the camera body 10 and the darker it becomes. The Av value is a value related to the aperture used when the imaging mode is the aperture priority mode. For example, the camera processor 11 designates the Av value and sends the Av value information to the lens unit 30 via the signal I / F 18.

  Further, it is assumed that the ND filter 32 can be switched between an ND off state and an ND on state.

  Regarding the F value, when the ND is off, the Av value and the F value correspond one-to-one, and the F value increases as the Av value increases. When ND is off, the MTF (Modulation Transfer Function) is good when the F value is in the range of F4 to F8. For example, F8 has the highest image quality.

  When the ND is off and the F value is larger than F11, the diaphragm 33 is narrowed, the light path for passing through the diaphragm 33 is narrowed, and diffraction tends to occur. Therefore, in the case of ND off and when the F value is larger than F11, the MTF value significantly decreases due to diffraction (also referred to as MTF drop).

  The first to third examples of exposure control are shown below. In the first to third examples, exposure control based on the exposure control information EC1 is assumed. Accordingly, the exposure amount is determined by the shutter speed and ISO sensitivity on the camera body 10 side, and the ND value and F value on the lens unit 30 side.

(First example of exposure control)
FIG. 7 is a view showing a first example of exposure control in the lens unit 30. Here, as a characteristic of the lens unit 30, the F value of the diaphragm 33 is variable in the range of F2.8 to F16. The ND value of the ND filter 32 is fixed at ND8.

  For example, when exposure control is performed in the aperture priority mode, Av (Aperture value) values that can be taken as lens exposure control instruction values (control ranges) are Av3 to Av11. As shown in FIG. 7, in the range of Av3 to Av7, the lens processor 31 sets ND off and adjusts the exposure amount. In the range from Av7 to Av11, the lens processor 31 sets ND on (ND value = 8).

  Therefore, in FIG. 7, the lens processor 31 adjusts the F value without depending on the ND value in the range of Av3 to Av7. Specifically, the lens processor 31 can achieve brightness equivalent to Av3 to Av7 by adjusting the F value in the range of F2.8 to F11 corresponding to Av3 to Av7. The lens processor 31 adjusts the F value depending on the ND value in the range of Av7 to Av11. Specifically, the lens processor 31 achieves brightness equivalent to Av7 to Av11 by adjusting the F value in a range of F4 to F16 that is smaller than F11 to 45 corresponding to Av3 to Av7. it can. That is, the lens unit 30 becomes dark when the ND is turned on, but the brightness corresponding to the Av value is ensured by making the F value smaller than when the ND is turned off.

  As described above, in the first example of the exposure control, the imaging device 5 derives the F value and the ND value based on the Av value instructed from the camera body 10 to the lens unit 30, thereby instructing the instructed Av value. It is possible to secure the brightness to realize the image quality and to suppress the deterioration of the image quality due to diffraction or the like.

  Further, when increasing the Av value according to the lens exposure control instruction value, the lens unit 30 narrows the diaphragm 33 until the F value becomes F11. The lens unit 30 switches from ND off to ND on when the lens exposure control instruction value reaches Av7 so that the MTF drop due to diffraction does not become significant, and widens the aperture 33 so that the F value becomes F4. Further, when the Av value is changed in the range of Av7 to Av11, the lens unit 30 fixes the ND value (dimming level) as ND on, for example, fixes ND value = 8, and changes the F value to change Av. Change the value and perform exposure control. Therefore, the imaging apparatus 5 can widen the control range of the exposure control by the lens unit 30 compared with the case where the ND filter 32 is not used, while simplifying the exposure control in the lens unit 30, and can suppress the decrease in the MTF value and improve the image quality. It can be improved.

(Second example of exposure control)
FIG. 8 is a diagram showing a second example of exposure control in the lens unit 30. Here, as a characteristic of the lens unit 30, the F value of the diaphragm 33 is variable in the range of F1.4 to F16. The ND value of the ND filter 32 is variable in the range of ND4 to ND64.

  For example, when exposure control is performed in the aperture priority mode, the control range of the Av value as the lens exposure control instruction value is Av1 to Av14. As shown in FIG. 8, in the range of Av1 to Av6, the lens processor 31 can change the F value in the range of F1.4 to F8 with ND off. In the range of Av6 to Av8, the lens processor 31 can fix the F value at F4 and change the ND value in the range of ND4 to ND16. Here, the exposure amount in the case of ND off and F8 is equal to the exposure amount in ND4 and F4. Therefore, the lens processor 31 can continuously and smoothly change the exposure amount in the range of Av1 to Av8.

  In the range of Av8 to Av10, the lens processor 31 can fix the ND value at ND16 and change the F value in the range of F4.0 to F8. Here, the exposure amount of F4 (fixed) of ND16 (variable) is equal to the exposure amount of F4 (variable) of ND16 (fixed).

  In the range of Av10 to Av12, the lens processor 31 can fix the F value at F8 and change the ND value in the range of ND16 to ND64. Here, the exposure amount of F8 (variable) of ND16 (fixed) and the exposure amount of F8 (fixed) of ND16 (variable) are equal.

  In the range of Av12 to Av14, the lens processor 31 fixes the ND value at ND64 and varies the F value from F8 to F16. Here, the exposure amount of F8 (fixed) of ND64 (variable) is equal to the exposure amount of F16 (variable) of ND64 (fixed). Therefore, the lens processor 31 can continuously and smoothly change the exposure amount even in the range of Av8 to Av14.

  Accordingly, in FIG. 8, the lens processor 31 adjusts the F value without depending on the ND value in the range of Av1 to Av6. Specifically, the lens processor 31 can achieve brightness equivalent to Av1 to Av6 by adjusting the F value in the range of F1.4 to F8 corresponding to Av1 to Av6. Further, the lens processor 31 adjusts the ND value while fixing the F value in the range of Av6 to Av8. Specifically, the lens processor 31 is fixed at F4 which is an F value smaller than F8 to F16 corresponding to Av6 to Av8, and the ND value is adjusted to ND4 to ND16, so that the brightness is the same as that of Av6 to Av8. Can be realized. That is, the lens unit 30 becomes dark when the ND is turned on, but the brightness corresponding to the Av value is ensured by making the F value smaller than when the ND is turned off. Further, the lens processor 31 adjusts the F value while fixing the ND value in the range of Av8 to Av10. Specifically, the lens processor 31 adjusts in the range of F4 to F8, which is an F value smaller than F16 to F32 corresponding to Av8 to Av10, and fixes the ND value at ND16, thereby being equivalent to Av8 to Av10. Can be achieved. The lens processor 31 adjusts the ND value while fixing the F value in the range of Av10 to Av12. Specifically, the lens processor 31 is fixed at F8, which is an F value smaller than F32 to F64 corresponding to Av10 to Av12, and the ND value is adjusted to ND16 to ND64, so that the brightness equivalent to Av10 to Av12 is obtained. Can be realized. Further, the lens processor 31 adjusts the F value while fixing the ND value in the range of Av12 to Av14. Specifically, the lens processor 31 adjusts in the range of F8 to F16, which is an F value smaller than F64 to F128 corresponding to Av12 to Av14, and fixes the ND value at ND64, thereby being equivalent to Av12 to Av14. Can be achieved.

  In the second example of exposure control, when the Av value is increased according to the lens exposure control instruction value, the lens processor 31 sets ND on when the Av value becomes Av6 or more, fixes the F value, and changes the ND value (first value). 2) and ND value fixing and F value change (an example of the first change process) are alternately repeated (repeated) to perform exposure control in the lens unit 30. Thereby, the lens unit 30 can perform exposure control over a wide range of Av1 to Av14 while sequentially switching between a change value and a fixed value in exposure control. The lens unit 30 can adjust the exposure while minimizing the change in the exposure amount by alternately repeating the ND value variable (F value fixed) and the F value variable (ND value fixed). Therefore, the imaging device 5 can improve the image quality by suppressing the decrease in the MTF value while finely switching the exposure control method in the lens unit 30.

(Third example of exposure control)
FIG. 9 is a diagram showing a third example of exposure control in the lens unit 30. In the second example, when performing exposure control in the range of Av1 to Av14, the lens processor 31 repeats ND value variable (F value fixed) and F value variable (ND value fixed) alternately multiple times. In the third example, the lens processor 31 can change the ND value within the variable range (ND4 to ND64) by switching the ND on at Av6 and then fixing the F value at F4. When the ND value reaches ND64, the lens processor 31 can change the F value within the variable range (F4 to F16) by fixing the ND value at ND64, and can change the F value until it reaches F16.

  That is, the lens processor 31 can fix the F value at F4 and change the ND value at ND4 to ND64 in the range of Av6 to Av10. Here, the exposure amount of F8 when ND is off is equal to the exposure amount of F4 at ND4. Therefore, the lens processor 31 can continuously change the exposure amount in the range of Av1 to Av10.

  In the range of Av10 to Av14, the lens processor 31 can fix the ND value at ND64 and change the F value in the range of F4 to F16. Here, the exposure amount of F4 (fixed) of ND64 (variable) is equal to the exposure amount of F4 (variable) of ND64 (fixed).

  Thus, in the third example of exposure control in the lens unit 30, when the lens unit 30 performs exposure control in the same Av value control range as in the second example, the ND is variable and the F value is fixed after the ND is turned on. Switching between variable value and fixed ND value can be done in one time. Therefore, the imaging device 5 can simplify the switching process by the lens processor 31.

  In the second and third examples of exposure control, exposure control may be performed in a range where the F value does not exceed F11. That is, in the second example, the lens processor 31 may set a range of ND64 and F11 or less in the control range of Av12 to Av14 as the control range of the exposure control. Even in this case, the imaging device 5 can realize high image quality while reducing the amount of light compared to the case of ND off and F11. In the second example and the third example, since the F value is equal to or less than F8 in the range of Av1 to Av12, the MTF is good. Therefore, good image quality can be realized in as wide a range as possible in Av1 to Av16.

  Note that adjustment information indicating how the ND value and the F value are adjusted based on the Av value as shown in the first to third examples of exposure control is held in the memory 37 of the lens unit 30. May be. The lens processor 31 may refer to the adjustment information held in the memory 37 and determine the ND value (or on / off of the ND filter 32) and the F value based on the instructed Av value.

  As mentioned above, although this indication was explained using an embodiment, the technical scope of this indication is not limited to the range as described in an embodiment mentioned above. It will be apparent to those skilled in the art that various modifications and improvements can be made to the embodiment described above. It is also apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present disclosure.

  The execution order of each process such as operation, procedure, step, and stage in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. ”And the like, and can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. is not.

  In the above embodiment, the imaging device 5 has a structure in which the lens unit 30 is directly attached to the camera body 10, but a structure in which a mount adapter is attached to the camera body 10 and the lens unit 30 is attached to the mount adapter. It may be. That is, the lens unit 30 may be attached to the camera body 10 via the mount adapter. For example, the camera body 10 and the lens unit 30 manufactured by the same manufacturer can be mounted via a mount adapter even if they cannot be directly mounted due to a manufacturing date shift or model change. The same applies to the case where the camera body 10 and the lens unit 30 manufactured by different manufacturers are mounted.

  In the embodiment described above, the registration processing of the exposure control information EC1 and EC2 and the exposure control using the registered exposure control information EC1 and EC2 are performed at different timings. For example, when the lens unit 30 is connected to the camera body 10 for the first time, the exposure control information EC1 and EC2 are registered. When the lens unit 30 is connected twice or more, exposure control using the exposure control information EC1 and EC2 is performed. Is called. Instead, the imaging device 5 generates exposure control information EC1 and EC2 corresponding to the lens unit 30 when connected for the first time, and the camera body 10 and the lens unit 30 generate the generated exposure control information EC1 and EC2. Exposure control may be performed according to EC2. In this case, the imaging device 5 can free a memory space in which the exposure control information EC1 and EC2 are held for a long time, for example.

DESCRIPTION OF SYMBOLS 5 Imaging device 10 Camera main body 10z Case 11 Camera processor 12 Shutter 13 Image sensor 15 Memory 16 Display part 17 Operation part 17z Release SW
18, 35 Signal I / F
21 Gain Controller 25, 45 Mount 27, 47 Electronic Contact 30 Lens Unit 31 Lens Processor 32 ND Filter 33 Aperture 34 Lens Group 37 Memory

Claims (20)

A camera body having an image sensor and a first processing unit;
A lens unit that has a lens that collects light from a subject and forms an image on the image sensor, and a neutral density filter that attenuates the amount of light from the subject.
The camera body includes a storage unit that stores first exposure control information corresponding to a lens unit having the neutral density filter,
The first processing unit performs first exposure control for adjusting the amount of light from the subject based on the first exposure control information.
Imaging device. A lens unit is attached to the camera body so that it can be replaced.
The storage unit holds a plurality of the first exposure control information different for each lens unit,
The first processing unit includes:
Get the identification information of the mounted lens unit,
Performing the first exposure control based on the first exposure control information corresponding to the identification information of the mounted lens unit;
The imaging device according to claim 1. A lens unit is attached to the camera body so that it can be replaced.
The storage unit stores second exposure control information corresponding to a lens unit that does not have the neutral density filter,
The first processing unit includes:
Determining whether the mounted lens unit is a lens unit having the neutral density filter;
When the mounted lens unit is a lens unit having the neutral density filter, the first exposure control is performed based on the first exposure control information,
When the mounted lens unit is a lens unit that does not have the neutral density filter, based on the second exposure control information, second exposure control for adjusting the amount of light from the subject is performed.
The imaging device according to claim 1 or 2. The first exposure control information includes control information of an aperture value, a shutter speed, a gain for amplifying an image signal obtained by the image sensor, and a dimming degree by the neutral density filter.
The imaging device according to claim 1. The second exposure control information includes control information of an aperture value, a shutter speed, and a gain for amplifying an image signal obtained by the imaging element.
The imaging device according to claim 3. The lens unit includes a second processing unit,
The first processing unit includes:
Sending information on an exposure control instruction value for performing at least a part of the first exposure control in the lens unit to the lens unit;
The second processing unit includes:
Obtaining information of the exposure control instruction value;
Based on the exposure control instruction value, to determine the aperture value and the degree of dimming by the neutral density filter,
The imaging device according to claim 4. The lens unit includes a second processing unit,
The second processing unit, when changing the exposure control instruction value, changes the aperture value while fixing the dimming degree.
The imaging device according to claim 6. The lens unit includes a second processing unit,
The second processing unit, when changing the exposure control instruction value, fixes the aperture value and changes the dimming degree.
The imaging device according to claim 6. The lens unit includes a second processing unit,
The second processing unit, when changing the exposure control instruction value, a first change process for changing the aperture value by fixing the light attenuation level, and changing the light attenuation level by fixing the aperture value. And the second change process to be performed repeatedly.
The imaging device according to claim 6. An exposure control method in an imaging apparatus comprising a camera body having an imaging element and a lens unit,
The lens unit includes a lens that collects light from a subject and forms an image on the image sensor, and a neutral density filter that attenuates the amount of light from the subject.
The camera body includes a storage unit that stores first exposure control information corresponding to a lens unit having the neutral density filter,
Performing a first exposure control for adjusting the amount of light from the subject based on the first exposure control information,
Exposure control method. The storage unit holds a plurality of the first exposure control information different for each lens unit,
The step of performing the first exposure control includes
Obtaining identification information of a lens unit attached to the camera body;
Performing the first exposure control based on the first exposure control information corresponding to the identification information of the mounted lens unit,
The exposure control method according to claim 10. The storage unit stores second exposure control information corresponding to a lens unit that does not have the neutral density filter,
The step of performing the first exposure control includes
Determining whether a lens unit attached to the camera body is a lens unit having the neutral density filter;
Performing the first exposure control based on the first exposure control information when the mounted lens unit is a lens unit having the neutral density filter,
When the mounted lens unit is a lens unit that does not have the neutral density filter, performing a second exposure control that adjusts the amount of light from the subject based on the second exposure control information; Further including
The exposure control method according to claim 10 or 11. The first exposure control information includes control information of an aperture value, a shutter speed, a gain for amplifying an image signal obtained by the image sensor, and a dimming degree by the neutral density filter.
The exposure control method according to any one of claims 10 to 12. The second exposure control information includes control information of an aperture value, a shutter speed, and a gain for amplifying an image signal obtained by the imaging element.
The exposure control method according to claim 12. In the camera body, sending information on an exposure control instruction value for performing at least a part of the first exposure control in the lens unit to the lens unit;
In the lens unit, obtaining information of the exposure control instruction value;
Determining, in the lens unit, the aperture value and the dimming degree by the neutral density filter based on the exposure control instruction value;
The exposure control method according to claim 13. The step of determining the aperture value and the dimming degree by the neutral density filter includes the step of changing the aperture value while fixing the dimming degree when changing the exposure control instruction value.
The exposure control method according to claim 15. The step of determining the aperture value and the dimming degree by the neutral density filter includes the step of changing the dimming degree by fixing the aperture value when changing the exposure control instruction value.
The exposure control method according to claim 15. The step of determining the aperture value and the dimming degree by the neutral density filter includes: a first changing process for changing the aperture value while fixing the dimming level when changing the exposure control instruction value; Repetitively performing a second change process for changing the dimming degree with a fixed value,
The exposure control method according to claim 15. An image pickup apparatus comprising: a camera body having an image pickup device; a lens unit that collects light from a subject to form an image on the image pickup device; and a lens unit that attenuates the amount of light from the subject. In addition,
Performing first exposure control for adjusting the amount of light from the subject based on first exposure control information corresponding to a lens unit having the neutral density filter;
A program for running An image pickup apparatus comprising: a camera body having an image pickup device; a lens unit that collects light from a subject to form an image on the image pickup device; and a lens unit that attenuates the amount of light from the subject. In addition,
Performing first exposure control for adjusting the amount of light from the subject based on first exposure control information corresponding to a lens unit having the neutral density filter;
The computer-readable recording medium which recorded the program for performing this.

Images