JP2008129467A - Imaging apparatus and imaging system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of achieving accurate AF control even when using various interchangeable lenses under various light sources, and performing AF processing at high speed when using a specified interchangeable lens. <P>SOLUTION: The imaging apparatus 1 includes: a focus detection means to perform focus detection by using light from a photographic optical system 11; a light source discrimination means 31 to discriminate the light source by using the light from the photographic optical system; and a control means 100 capable of generating information on focus control by using the detected result of a focus state and the discriminated result of the light source. The control means restricts the formation of the information to be used for the focus control using the discriminated result of the light source according to information on the chromatic aberration amount of the photographic optical system. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging apparatus that performs focus control, and more particularly to an imaging apparatus that performs focus control according to information about a light source.

  There is a so-called TTL (Through The Lens) phase difference detection method as an AF (autofocus) method for an imaging apparatus such as a digital single lens reflex camera. In a camera that employs a TTL phase difference detection method, light incident from a photographing lens is separated by a light separation member such as a mirror, and transmitted light is guided to an imaging system and reflected light is guided to a focus detection system. Thus, in the TTL phase difference detection type camera, the imaging system and the focus detection system are provided separately. For this reason, the following problems arise.

  The spectral sensitivity characteristics of the imaging system are usually most sensitive to light of about 400 to 650 nm in order to give color reproducibility that matches the characteristics of the human eye in the case of a general silver salt film. ing.

  On the other hand, a silicon photodiode constituting an imaging device such as a CMOS sensor used in an imaging system generally has a sensitivity peak at about 800 nm, and has a sensitivity up to about 1100 nm on the long wavelength side. However, in order to place importance on color reproducibility, light having a wavelength outside the above frequency range is blocked by a filter at the expense of sensitivity.

  In addition, a photoelectric conversion element as a sensor that performs focus detection by the phase difference detection method generally has a sensitivity up to about 1100 nm. However, the focus detection can be performed even on a low-luminance subject, and an accurate focus detection can be performed by irradiating the subject with auxiliary light in the near-infrared region (about 700 nm) from the camera under a low luminance. In many cases, it has sensitivity up to a long wavelength region.

  FIG. 8 shows spectral sensitivities of various light sources, image sensors, and auxiliary light. The horizontal axis indicates the wavelength. The vertical axis indicates the relative focus position due to relative energy or chromatic aberration of the lens. In the figure, C represents chromatic aberration of the photographing lens, and B, G, and R represent the respective spectral sensitivities of the blue pixel, green pixel, and red pixel of the primary color image sensor. F indicates a fluorescent lamp, L indicates a flood lamp, and A indicates the spectral sensitivity of the auxiliary light described above.

  From the figure, it is understood that the wavelength component of the fluorescent lamp contains almost no wavelength component longer than 620 nm, but the flood lamp has a higher relative sensitivity as the wavelength becomes longer.

  On the other hand, the focal position of the chromatic aberration C of the lens changes according to the wavelength, and the focal length increases as the wavelength becomes longer.

  Therefore, when a focus detection sensor having a maximum sensitivity at 700 nm is used, the focus position to be detected differs between the fluorescent lamp and the flood lamp with a small long wavelength component, and as a result, the focus on the image sensor is also shifted. End up.

  A camera that corrects the focus position is disclosed in Patent Document 1 for the problem that the focus position detected by the focus detection system shifts in accordance with the spectral sensitivity of the light source.

  In this camera, the output of two types of sensors having different spectral sensitivities is compared to determine the type of the light source, and the focus position is corrected to correct the focus shift due to the spectral characteristics of the light source.

  Further, in Patent Document 2, the amount of chromatic aberration of an interchangeable lens is stored in an in-lens memory, and a method of obtaining a defocus correction amount by multiplying a lens chromatic aberration amount by a predetermined coefficient based on a determination result of the type of light source. It is disclosed.

Further, Patent Document 3 discloses a method for obtaining a defocus correction amount by acquiring chromatic aberration amount information stored in a photographing lens.
JP 2000-275512 A (paragraphs 0041 to 0110, FIGS. 3 to 10 and the like) JP-A-62-174710 (page 6, upper left column, line 2 to page 7, upper left column, line 3, FIG. 9 etc.) Japanese Patent Laying-Open No. 2005-208300 (paragraphs 0144 to 0159, FIG. 14 and the like)

  However, in the camera disclosed in Patent Document 1, the correction amount of chromatic aberration is handled as a fixed value, and it cannot be directly applied to an interchangeable lens autofocus camera. This is because when the chromatic aberration varies depending on individual lens differences, the defocus correction amount becomes excessive or insufficient.

  In Patent Documents 2 and 3, the defocus correction amount is obtained according to the chromatic aberration amount of the interchangeable lens. However, even in the case of an interchangeable lens that has a very small chromatic aberration that originally does not require defocus correction by the light source, the light source discrimination operation and the calculation of the correction amount are always performed, so that time is wasted on wasteful processing. Therefore, when this is applied to an AF camera, processing related to AF for the light source discrimination operation and correction amount calculation is delayed, and the release time lag is also increased.

  The present invention enables high-precision AF control even when various interchangeable lenses are used under various light sources, and can perform high-speed AF processing when a specific interchangeable lens is used. One of the purposes is to provide a device.

  An imaging apparatus according to an aspect of the present invention includes a focus detection unit that detects a focus state of a photographing optical system, a light source detection unit that detects information about a light source, a focus control using a detection result of the focus state and information about the light source. Control means capable of generating information on The control means limits generation of information used for the focus control using the information about the light source according to the information about the chromatic aberration amount of the photographing optical system.

  Note that an imaging system including the imaging device and a lens device that can be attached to and detached from the imaging device and has a photographing optical system also constitutes another aspect of the present invention.

  According to another aspect of the present invention, there is provided a method for controlling an imaging apparatus using a step of detecting a focus state of a photographing optical system, a step of detecting information on a light source, a detection result of a focus state, and information on a light source. And an information generation step capable of generating information used for focus control. In the information generation step, the generation of information used for focus control using information regarding the light source is limited according to information regarding the amount of chromatic aberration of the photographing optical system.

  According to the present invention, in accordance with the amount of chromatic aberration of the photographing optical system (interchangeable lens), it is determined whether or not to generate information used for focus control using the light source discrimination result. Therefore, when using an interchangeable lens with a small focus control error caused by chromatic aberration, the calculation processing of the information using the light source discrimination result can be omitted, and the processing related to AF can be performed at high speed. As a result, the release time lag can be reduced.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a single-lens reflex camera system (imaging system) that is an embodiment of the present invention. The camera system includes a single-lens reflex camera (imaging device) 1 and an interchangeable lens (lens device) 11 that is detachably attached to the camera 1.

  In the figure, an optical component, a mechanical component, an electric circuit, an image sensor (or film), and the like are accommodated in the camera 1 and an image (or photograph) can be taken.

  Reference numeral 2 denotes a main mirror, which is disposed obliquely in the photographing optical path in the viewfinder observation state and retracts out of the photographing optical path in the photographing state. Further, the main mirror 2 is a half mirror, and when arranged in the photographing optical path, transmits about half of the light beam from the subject to a focus detection optical system described later.

  Reference numeral 3 denotes a focusing plate, which constitutes a part of the finder optical system and is disposed on a planned imaging plane of a photographing optical system described later. Reference numeral 4 denotes a finder optical path changing pentaprism. Reference numeral 5 denotes an eyepiece, and the photographer can observe the subject image by observing the focus plate 3 from this window.

  Reference numerals 6 and 7 denote a first imaging lens and a photometric sensor for measuring the subject luminance in the viewfinder observation screen. Reference numerals 30 and 31 denote a second imaging lens and a light source detection circuit for measuring the luminance of the subject in the viewfinder observation screen.

  Reference numeral 8 denotes a focal plane shutter. Reference numeral 9 denotes an image sensor, which is composed of a CCD sensor or a CMOS sensor. Reference numeral 25 denotes a sub-mirror, which is disposed obliquely in the photographing optical path together with the main mirror 2 in the finder observation state, and retracts out of the photographing optical path in the photographing state. The sub mirror 25 bends the light beam transmitted through the main mirror 2 arranged in the photographing optical path downward and guides it to a focus detection unit described later.

  A focus detection unit 26 includes a secondary imaging mirror 27, a secondary imaging lens 28, a focus detection sensor 29, a focus detection circuit described later, and the like. The secondary imaging mirror 27 and the secondary imaging lens 28 constitute a focus detection optical system, and a secondary imaging surface of the photographing optical system is formed on the focus detection sensor 29. The focus detection unit 26 detects a focus state (pixel information having a phase difference) of the photographing optical system by a so-called phase difference detection method, and sends the detection result to a camera microcomputer to be described later.

  A mount contact group 10 serves as a communication interface between the camera 1 and the interchangeable lens 11.

  Reference numerals 12 to 14 denote lens units. A first lens unit (hereinafter referred to as a focus lens) 12 performs focus adjustment by moving on the optical axis. The second lens unit 13 performs zooming by changing the focal length of the photographing optical system by moving on the optical axis.

  Reference numeral 14 denotes a fixed third lens unit. Reference numeral 15 denotes an aperture. A focus driving motor 16 moves the focus lens 12 in the optical axis direction during AF. Reference numeral 17 denotes an aperture drive motor for changing the aperture diameter of the aperture 15.

  A distance encoder 18 slides a brush 19 attached to the focus lens 12 to read the position of the focus lens 12 and generate a signal corresponding to the subject distance.

  Next, the electric circuit configuration of the camera system will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same component as FIG.

  First, the circuit configuration in the camera 1 will be described. Connected to the camera microcomputer 100 are a focus detection circuit 105, a photometric sensor 7, a light source detection circuit 31, an image size setting unit 112, an AF mode setting unit 113, a shutter control circuit 107, a motor control circuit 108, and a liquid crystal display circuit 111. ing. The camera microcomputer 100 communicates with the lens microcomputer 150 arranged in the interchangeable lens 11 via the mount contact 10.

  The light source detection circuit 31 includes a visible light sensor 311 and an infrared light sensor 312 having different spectral sensitivities (detecting light in different wavelength regions). The light source detection circuit 31 performs charge accumulation control and charge readout control of the visible light sensor 311 and the infrared light sensor 312 in accordance with signals from the camera microcomputer 100. Then, the luminance information obtained by the sensors 311 and 312 is output to the camera microcomputer 100.

  The camera microcomputer 100 performs A / D conversion on the luminance information, and generates a luminance value ratio (luminance ratio) detected by the visible light sensor 311 and the infrared light sensor 312 as information on the light source.

  The focus detection circuit 105 performs charge accumulation control and charge read control of a pair or a plurality of pairs of CCD line sensors provided in the focus detection sensor 29 according to a signal from the camera microcomputer 100. Then, pixel information from each line sensor (information representing two images formed on the pair of line sensors) is output to the camera microcomputer 100.

  The camera microcomputer 100 A / D converts this pixel information and detects the phase difference of the pixel information. Further, a defocus amount of the photographing optical system, that is, information used for focus control is obtained based on the phase difference.

  Here, as will be described in detail later, the camera microcomputer 100 performs correction according to the light source of the defocus amount (hereinafter referred to as light source correction of the defocus amount) as necessary.

  Based on the defocus amount (the light source is not corrected or the light source is corrected), the focus sensitivity information of the photographing optical system, and the like, the drive amount of the focus lens 12 (focus drive) The driving amount of the motor 16) is calculated. The driving amount information of the focus lens 12 is transmitted to the lens microcomputer 150. The lens microcomputer 150 controls the focus drive motor 16 according to the received drive amount information. Thereby, AF control in the interchangeable lens 11 is performed, and focusing is obtained.

  The shutter control circuit 107 performs energization control of the shutter front curtain drive magnet MG-1 and the shutter rear curtain drive magnet MG-2 constituting the focal plane shutter 8 in accordance with a signal from the camera microcomputer 100. As a result, the shutter front curtain and rear curtain travel, and the image sensor 9 is exposed.

  The motor control circuit 108 controls the mirror drive motor M in accordance with a signal from the camera microcomputer 100. Thereby, the up / down operation of the main mirror 2 and the charging operation of the focal plane shutter 8 are performed.

  SW1 is a switch that is turned on by a first stroke (half-press) operation of a release button (not shown) to start photometry and AF.

  SW2 is a switch that is turned on by a second stroke (full press) operation of the release button and starts shutter running, that is, an exposure operation. In addition to the switches SW1 and SW2, the camera microcomputer 100 reads the states of various switches such as an ISO sensitivity setting switch, an aperture setting switch, and a shutter speed setting switch which are not shown.

  The image size setting unit 112 is an operation unit for setting an image size (resolution) by the user. The camera microcomputer 100 reads the state of the image size setting unit 112 and changes the compression rate of the image data acquired by the image sensor 9. Here, the image size can be set in three types: high resolution (L) without compression, medium resolution (M) with low compression, and low resolution (S) with high compression.

  The AF mode setting unit 113 is an operation unit that sets an AF mode (focus mode) by the user. The camera microcomputer 100 reads the state of the AF mode setting unit 113 and changes the AF mode. Here, two types of AF modes can be set: a normal AF mode in which a normal AF operation is performed, and a servo AF mode in which a focus position is predicted in accordance with a shooting timing following a moving subject. The AF mode can also be referred to as a shooting mode using AF.

  The liquid crystal display circuit 111 controls the in-finder display 24 and the external display 42 according to signals from the camera microcomputer 100.

  Next, an electric circuit configuration in the interchangeable lens 11 will be described. As described above, the interchangeable lens 11 is electrically connected to the camera 1 via the mount contact 10. The mount contact 10 is a contact L0 which is a power contact for the focus drive motor 16 and the aperture drive motor 17 in the interchangeable lens 11, and a power contact L1 for the lens microcomputer 150, and a clock for serial data communication. Contact L2. Further, a data transmission contact L3 from the camera 1 to the interchangeable lens 11, a data transmission contact L4 from the interchangeable lens 11 to the camera 1, a motor ground contact L5 to the motor power supply, and a power supply for the lens microcomputer 150. And a ground contact L6.

  The lens microcomputer 150 is connected to the camera microcomputer 100 via the mount contact 10 and controls the focus drive motor 16 and the aperture drive motor 17 in accordance with signals from the camera microcomputer 100. Thereby, focus adjustment and light quantity adjustment are performed.

  Reference numerals 50 and 51 denote a photodetector and a pulse plate. The pulse plate 51 is rotated by the focus drive motor 16. When the pulse plate 51 rotates, the photodetector 50 receives detection light intermittently and outputs a pulse signal. The lens microcomputer 150 obtains position information of the focus lens 12 at the time of focus adjustment by counting the number of pulses from the photodetector 50. The lens microcomputer 150 controls the focus drive motor 16 so that the position information of the focus lens 12 matches the drive amount for focusing the focus lens 12 transmitted from the camera microcomputer 100. Thereby, focus adjustment is performed.

  Reference numeral 18 denotes the above-described distance encoder, and the position information of the focus lens 12 read here is input to the lens microcomputer 150. The lens microcomputer 150 converts the position information into subject distance information and transmits it to the camera microcomputer 100.

  Next, the spectral characteristics of the visible light sensor 311 and the infrared light sensor 312 will be described with reference to FIG. In the figure, the horizontal axis represents wavelength (nm) and the vertical axis represents intensity. A is the spectral sensitivity characteristic of the visible light sensor 311, and B is the spectral sensitivity characteristic of the infrared light sensor 312.

  As can be seen from this figure, the visible light sensor 311 mainly detects light in the visible light region, and the infrared light sensor 312 mainly detects light in the long wavelength region having peak sensitivity in the near infrared light region. .

  Next, the AF operation of the camera system of the present embodiment will be described using the flowchart of FIG. This AF operation is mainly executed by the camera microcomputer 100 as control means in accordance with a computer program.

  When SW1 of the camera 1 shown in FIG. 2 is turned on, the operation starts from step (abbreviated as S in the figure) 101. The camera microcomputer 100 causes the focus detection sensor 29 in the focus detection unit 26 including the focus detection circuit 105 to perform charge accumulation, and generates pixel information corresponding to the focus state of the photographing optical system.

  In step 102, the camera microcomputer 100 calculates the defocus amount of the photographing optical system based on the acquired pixel information shift (phase difference).

  In step 103, the camera microcomputer 100 reads the states of the image size setting unit 112 and the AF mode setting value 113.

  In step 104, a correction determination value serving as a determination criterion for performing light source correction on the defocus amount calculated in step 102 or prohibiting (limiting) it is determined.

  Here, a method of determining the correction determination value will be described with reference to FIG. FIG. 6 is an example of correction determination values for the image size (resolution) and the AF mode. The correction determination value data is stored in advance in a ROM table (not shown) of the camera microcomputer 100. The camera microcomputer 100 reads the correction determination value corresponding to the image size and AF mode read in step 103 from the ROM table and determines it as the current correction determination value.

In general, when the image size is not compressed, the permissible circle of confusion (allowable defocus amount) is 2 to 3 times the pixel pitch of the image sensor 9. For example, when F: lens aperture value = 1.0 and pixel pitch: P = 7.0 μm, δ: allowable confusion circle is
δ = P × 3.0 = 7 × 3.0 = 21.0 μm
It is. When this is converted into the defocus amount d,
d = F × δ = 1.0 × 21.0 = 21.0 μm
It is.

  In the case of high resolution (L) in the normal AF mode, the image size is not compressed. Therefore, if the error of the defocus amount corresponding to the light source is 21 μm or less, no correction is necessary. For this reason, the correction determination value is set to 21 μm.

  In addition, in the case of medium resolution or low resolution, the permissible circle of confusion increases depending on the compression rate of the image, so the correction determination value is also set larger than in the case of high resolution (L) in the normal AF mode. For example, the medium resolution is about 1.5 times the high resolution setting value, and the low resolution is 2.0 times the high resolution setting value.

  Furthermore, when the AF mode is set to the servo AF mode, the AF speed is prioritized, and therefore the permissible circle of confusion is made larger than that in the normal AF mode. For example, in the servo AF mode, it is set to 2.0 times the set value in the normal AF mode.

  In step 105, the camera microcomputer 100 requests the lens microcomputer 150 to transmit chromatic aberration amount data specific to the interchangeable lens (imaging optical system). This request is transmitted to the lens microcomputer 150 via the serial communication lines LCK, LDO, and LDI shown in FIG.

  Upon receiving the request, the lens microcomputer 150 first analyzes the content of the request (communication). If the request is a transmission request for chromatic aberration data, the chromatic aberration data corresponding to the current focal length and focus lens position of the photographing optical system is read from the memory (ROM table) 150a in the lens microcomputer 150. That is, the chromatic aberration amount data is measured in advance in association with the focal length and the focus lens position for each individual interchangeable lens, and is stored in the memory 150a. The lens microcomputer 150 returns the chromatic aberration amount data to the camera microcomputer 100 via serial communication lines LCK, LDO, and LDI.

  In step 106, the camera microcomputer 100 detects information about the light source through the light source detection circuit 31. The light source detection method will be described later.

Further, the camera microcomputer 100 determines whether to perform light source correction on the defocus amount calculated in step 102 or prohibit it. Specifically, when the chromatic aberration amount of the photographing optical system acquired in step 105 is equal to or smaller than the correction determination value determined in step 104, it is determined that the light source correction of the defocus amount is unnecessary (should be prohibited), and step 111 Migrate to This direct shift to step 111 (step 107 to be described later) limits. On the other hand, if the chromatic aberration amount is larger than the correction determination value, it is determined that the light source correction of the defocus amount is necessary, and the flow shifts to step 107.

  In step 107 and step 108, the camera microcomputer 100 drives the light source detection circuit 31 and reads luminance information from the visible light sensor 311 and the infrared light sensor 312. Then, the ratio of luminance information from the visible light sensor 311 and the infrared light sensor 312, that is, the luminance ratio is calculated, and the correction coefficient is calculated from the table shown in FIG. 7 according to the luminance ratio (infrared light / visible light). read out.

  FIG. 7 is a correction coefficient data table stored in the memory (ROM table) 100 a in the camera microcomputer 100. The horizontal axis indicates the luminance ratio between the visible light sensor 311 and the infrared light sensor 312, and the vertical axis indicates the correction coefficient.

  In steps 109 and 110, the chromatic aberration amount data acquired in step 107 is multiplied by the correction coefficient obtained in step 108. Further, the multiplication result is added to the defocus amount obtained in step 102 to calculate the defocus amount after the light source correction.

  Note that correcting the defocus amount is not only generating a new defocus amount (defocus amount after light source correction), and in this sense, correcting in the present embodiment can be rephrased as generating. .

  In step 111, when the defocus amount after light source correction is within a specific range, it is determined that the focus is achieved, and the process proceeds to step 113. If the defocus amount after light source correction is larger than the specific range, the process proceeds to step 112, and the drive amount for focusing the focus lens 12 is calculated from the defocus amount after light source correction. Then, the driving amount information is transmitted to the lens microcomputer 150 via the serial communication lines LCK, LDO, and LDI described above.

  The lens microcomputer 150 that has received the drive amount information drives the focus drive motor 16 by determining the drive direction of the focus drive motor 16 according to the drive amount information. The process returns to step 101, and the operations of the steps described above are repeated until it is determined in step 111 that focus is achieved.

  In step 113, it is determined whether SW2 is ON. If it is ON, the process proceeds to step 201 shown in FIG. If SW2 is OFF, the AF operation process is terminated.

  Next, the photographing operation will be described with reference to FIG. When the above-described AF operation is completed and SW2 is ON, the camera microcomputer 100 obtains the subject brightness BV from the photometric value from the photometric sensor 7 that measures the subject brightness in step 201. Then, the subject brightness BV is added to the set ISO sensitivity SV to obtain the exposure value EV, and the aperture value AV and the shutter speed TV are calculated from the exposure value EV.

  In step 202, the camera microcomputer 100 moves the main mirror 2 up and retracts it from the photographing optical path. At the same time, the camera microcomputer 100 instructs the lens microcomputer 150 to reduce the aperture 15 to the aperture value AV determined in step 202. The lens microcomputer 150 receives the command and drives the aperture drive motor 17.

  Thereafter, when the main mirror 2 is completely retracted from the photographing optical path, in step 203, the camera microcomputer 100 energizes the shutter front curtain drive magnet MG-1, and starts the opening operation of the focal plane shutter 8.

  When the predetermined shutter opening time elapses, the process proceeds to step 204 where the camera microcomputer 100 energizes the shutter rear curtain drive magnet MG-2 and closes the rear curtain of the focal plane shutter 8. Thereby, the exposure of the image sensor 9 is completed.

  In step 205, the main mirror 2 is moved down and placed in the photographing optical path, and the photographing operation is terminated.

  As described above, according to the present embodiment, whether or not the detected defocus amount is light source corrected by comparing the chromatic aberration amount stored in the interchangeable lens with the correction determination value set on the camera side. To decide. Therefore, it is possible to prevent light source correction of the defocus amount from being performed for an interchangeable lens that originally has a small defocus amount error due to chromatic aberration. For this reason, it is possible to omit the arithmetic processing related to light source correction, and as a result, it is possible to speed up the processing related to AF and reduce the release time lag.

  In addition, in this embodiment, the correction determination value is not a fixed value, but an optimal value corresponding to the resolution (image size) of the captured image and the AF mode is used, so that the necessity / unnecessity (limitation) of light source correction is more accurately determined. Can be determined.

  Also, in the servo AF mode, the AF operation can be satisfactorily followed even for a fast-moving subject by changing the correction determination value in a direction in which light source correction is not performed.

  In the above embodiment, the case where the defocus amount as the focus detection result is corrected has been described. However, the present invention is not limited to this. For example, the focus lens drive amount calculated based on the defocus amount can be corrected. The correction target in the present invention may be any information as long as it is information used for focus control such as a defocus amount and a focus lens drive amount.

  In the above embodiments, a single-lens reflex camera has been described. However, the present invention can also be applied to a lens exchange type video camera that performs phase difference detection AF.

1 is a schematic diagram showing a configuration of a single-lens reflex camera system that is an embodiment of the present invention. FIG. The block diagram which shows the electric circuit structure in the camera system of an Example. The figure which shows the spectral sensitivity characteristic of the visible light sensor and infrared light sensor for a light source detection which are used for the camera system of an Example. 6 is a flowchart showing the operation of the camera system of the embodiment. 6 is a flowchart showing the operation of the camera system of the embodiment. The table | surface which shows the correction determination value with respect to the image size and AF mode in the camera system of an Example. The figure which shows the correction coefficient with respect to the infrared light / visible light of the camera system of an Example. The figure which shows the spectral sensitivity of a light source, an image pick-up element, and auxiliary light.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera 31 Light source detection circuit 11 Interchangeable lens 12 Focus lens 26 Focus detection circuit 100 Camera microcomputer 150 Lens microcomputer

Claims (6)

Focus detection means for detecting the focus state of the imaging optical system;
Light source detection means for detecting information about the light source;
Control means capable of generating information used for focus control using the detection result of the focus state and information on the light source;
The image pickup apparatus, wherein the control unit restricts generation of information used for the focus control using information about the light source according to information about a chromatic aberration amount of the photographing optical system.   When the amount of chromatic aberration is larger than a specific value, the control unit generates information used for the focus control using information on the light source and the detection result of the focus state, and the amount of chromatic aberration is smaller than the specific value. 2. The imaging apparatus according to claim 1, wherein information used for the focus control is generated using the detection result of the focus state without using the information regarding the light source.   The imaging apparatus according to claim 2, wherein the specific value is a value corresponding to a resolution of a captured image.   The imaging apparatus according to claim 2, wherein the specific value is a value corresponding to a focus mode of the imaging apparatus. An imaging device according to any one of claims 1 to 4,
An imaging system comprising: a lens device that is detachable from the imaging device and has a storage unit that stores information relating to the imaging optical system and the chromatic aberration amount. Detecting a focus state of the photographing optical system;
Detecting information about the light source;
An information generation step capable of generating information used for focus control using the detection result of the focus state and information about the light source;
In the information generation step, the generation of information used for the focus control using the information on the light source is limited according to the information on the chromatic aberration amount of the photographing optical system.