JP2019028281A - Imaging System - Google Patents

Abstract

To provide an imaging system enabling even a beginner user to easily change setting when insufficient light quantity causes a failure photograph upon bounce photographing.SOLUTION: An imaging apparatus has exposure condition setting means, and an illuminating device includes: light emission means irradiating a photographing field with light; irradiation direction varying means changing an irradiation direction; irradiation direction determination means automatically driving the irradiation direction varying means and determining an irradiation direction; light emission condition setting means capable of setting a light emission condition for determining an exposure condition; distance measurement means capable of measuring a subject distance between a subject to be imaged and the illuminating device, and a ceiling distance between a ceiling and the illuminating device; and display means notifying a user of information. The imaging apparatus is provided with correct exposure condition calculation means calculating a correct value of setting about exposure using the subject distance measured by the distance measurement means and the exposure condition set by the exposure condition setting means, and displays the correct value calculated by the correct exposure condition calculation means in the display means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging system, and more particularly to strobe shooting control.

  2. Description of the Related Art Conventionally, photographing with a camera or an electronic camera (imaging device) includes so-called bounce photographing in which strobe light from a strobe device is emitted toward a ceiling and diffuse reflected light is emitted from a ceiling or the like to a subject. According to bounce shooting, the subject can be indirectly illuminated, so that it is possible to depict with soft light.

  In addition, the strobe device that performs bounce shooting performs pre-flash, radar irradiation, etc., and the reflected light of the subject and the ceiling is measured by the light receiving sensor of the strobe device, and the subject is depicted with soft light based on the measured value Auto bounce drive control has been devised that determines and drives the optimum strobe head angle as much as possible. As a result, the photographer can perform optimum bounce shooting without setting the head portion angle of the strobe.

  For example, in Patent Document 1, a distance to an object such as an object or a person in front of the camera and a distance to an object such as a ceiling above the camera are obtained, and as a result, strobe light emission to the ceiling during bounce shooting is obtained. A camera capable of bounce photography that can automatically set the head portion angle of the strobe at the time is disclosed.

However, because bounce shooting emits light toward the ceiling and walls,
1) The distance of the subject from the light-emitting unit is increased.
2) Light cannot reach due to diffusion on the ceiling
For some reasons, depending on the camera exposure condition settings (Tv value, Av value, ISO sensitivity value, etc.), there may be a failure photo that is not intended by the user due to insufficient light quantity.

  In this case, since it is necessary to change the exposure condition setting of the camera (Tv value, Av value, ISO sensitivity value, etc.) and take a picture again, a technique for notifying the user of that fact is known. For example, Patent Document 2 discloses a camera that warns the photographer when it is detected that the photographing situation is inappropriate for bounce irradiation based on the distance to the subject.

Japanese Patent Laying-Open No. 2015-4933 Japanese Patent Laid-Open No. 9-138446

  However, since the novice user is not used to shooting, there is a possibility that it will not be understood what kind of setting change should be made only by giving a warning.

  Accordingly, an object of the present invention is to provide an image pickup system that can be easily changed even by a novice user when a failed photo is caused due to a lack of light quantity at bounce shooting.

  In order to achieve the above object, an imaging system according to the present invention is an imaging system including an imaging device and a lighting device built in or attached to the imaging device, and the imaging device can set an exposure condition. The exposure apparatus has a suitable exposure condition setting means, and the illumination device irradiates light to irradiate a photographing field, and moves the movable part provided with the light emission means to change the light irradiation direction of the light emission means. By automatically driving the direction variable means and the irradiation direction variable means, the irradiation direction driving means for changing the light irradiation direction of the light emitting means, and the light irradiation direction driven by the irradiation direction driving means are determined. Illuminating direction determining means, a light emitting condition setting means capable of setting a light emitting condition for determining the exposure condition, a subject distance between the subject to be imaged and the lighting device, and a ceiling between the ceiling and the lighting device. A distance measuring unit capable of measuring a distance, and a display unit for notifying a user of information, and the exposure from the subject distance measured by the distance measuring unit and the exposure condition set by the exposure condition setting unit And an appropriate exposure condition calculation means for calculating an appropriate value for the setting, and the appropriate value calculated by the appropriate exposure condition calculation means is displayed on the display means.

  Another imaging system according to the present invention is an imaging system including an imaging device and an illumination device built in or attached to the imaging device, wherein the imaging device can set an exposure condition. A light emitting means for irradiating light onto the photographing object field, and an irradiation direction variable means for moving a movable part provided with the light emitting means to change the light irradiation direction of the light emitting means. , By automatically driving the irradiation direction variable means, an irradiation direction driving means for changing the light irradiation direction of the light emitting means, and an irradiation direction determination for determining the irradiation direction of the light driven by the irradiation direction driving means. Measurement means, a light emission condition setting means capable of setting a light emission condition for determining the exposure condition, a subject distance between a subject to be imaged and the lighting device, and a ceiling distance between a ceiling and the lighting device A distance measuring unit and a display unit for notifying the user of information, and an appropriate value for exposure setting from the subject distance measured by the distance measuring unit and the exposure condition set by the exposure condition setting unit. Appropriate exposure condition calculation means for calculating the exposure value, and the exposure condition setting means is operated to automatically change to an appropriate value calculated by the appropriate exposure condition calculation means.

  According to the present invention, even if a novice user can easily change a setting when a failed photograph is caused due to insufficient light quantity during bounce shooting.

Strobe auto-bounce drive control flowchart of an embodiment of the present invention Shooting control flowchart of the camera of the embodiment of the present invention Strobe bounce drive control flowchart of an embodiment of the present invention The block diagram which showed the camera structural example of embodiment of this invention 1 is a block diagram showing an example of a strobe configuration according to an embodiment of the present invention. 1 is an external view showing an outline of the entire camera and strobe of an embodiment of the present invention. FIG. 2 is an external view showing the horizontal and vertical head unit angles of the strobe of the embodiment of the present invention. FIG. 2 is an external view showing a tilt state of a strobe according to an embodiment of the present invention. FIG. 3 is an external view showing an example of calculating the head angle of the strobe according to the embodiment of the present invention. Explanatory drawing of the flash mode of the strobe of Embodiment 1 of the present invention Flowchart of a specific example for obtaining the bounce time limit distance limL according to the embodiment of the present invention Table of attenuation change according to head angle according to an embodiment of the present invention

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

(First embodiment)
1 to 3 and FIGS. 11 to 12 are a flowchart and a table of an imaging device and a strobe device according to the embodiment of the present invention. 4 is a block diagram of the camera, and FIG. 5 is a block diagram of the strobe. FIG. 6 is an external view of the camera and the external strobe. FIGS. 7 to 9 are external views of the external strobe. Hereinafter, with reference to FIGS. 1 to 12, an imaging system of an imaging device and a strobe device according to an embodiment of the present invention will be described.

(Camera configuration)
First, the configuration of the camera 100 will be described with reference to the block diagram of FIG. 4 and the external view of FIG. Reference numeral 101 denotes a microcontroller (hereinafter referred to as camera MPU) of the camera 100 for controlling the system such as a photographing sequence. In addition, the camera MPU 101 sets the exposure condition according to the exposure condition (Tv value, Av value, ISO sensitivity value) and the shooting mode arbitrarily set by the photographer and the exposure of the object field obtained from the photometry unit 112 described later. This is exposure condition setting means for setting. Reference numeral 103 denotes an image sensor such as a CCD or CMOS that converts the reflected light from the subject into an electric signal, and reference numeral 102 denotes a timing signal generation circuit that generates a timing signal necessary for operating the image sensor 103.

  Reference numeral 104 denotes an A / D converter that converts analog image data read from the image sensor into digital image data. Reference numeral 105 denotes a memory controller that controls reading / writing of the memory, refresh operation of the buffer memory 106, and the like. Reference numeral 107 denotes an image display unit that displays image data stored in the buffer memory, 108 denotes an interface for connection with a recording medium, and 109 denotes a recording medium such as a memory card or a hard disk. The motor control unit 110 controls the motor (not shown) according to the signal from the camera MPU 101 during the exposure operation, thereby causing the mirror (not shown) to be raised and lowered and the shutter to be charged.

  In accordance with a signal from the camera MPU 101, the shutter control unit 111 cuts off energization of a shutter front curtain (SH front curtain) and a shutter rear curtain (SH rear curtain) that are not shown and travels the curtain to control the exposure operation. The photometry unit 112 outputs to the camera MPU 101 the output from the photometry sensor 113 obtained by dividing the screen into a plurality of areas as the luminance signal of each area in the screen. The camera MPU 101 converts this luminance signal by an A / D converter (not shown), and controls a shutter control value (Tv value), aperture control value (Av value), gain setting value (ISO sensitivity value) for shooting exposure adjustment. ) And other photometric calculations. Similarly, the photometry unit 112 outputs a luminance signal when the built-in strobe 119 or strobe 200 emits preliminary (pre) light toward the subject to the camera MPU 101, and also calculates the strobe main light emission amount during exposure.

  The lens control unit 114 communicates with the camera MPU 101 via a lens mount contact (not shown) with respect to the lens 300 in FIG. 6 and operates a lens drive motor and a lens aperture motor (not shown) to adjust the lens focus and aperture. Is controlling. A focus detection unit 115 has a function of detecting a defocus amount with respect to a subject for AF (autofocus) using a conventional phase difference detection method or the like.

  Reference numeral 116 denotes an attitude detection unit that detects the tilt of the camera with respect to the rotation direction around the optical axis. Reference numeral 117 denotes an operation member of the camera, and SW1 is turned on by a first stroke of a release button (not shown) to start AF and photometry. SW2 is turned on by the second stroke of the release button to start the exposure operation. SW1 and SW2 and other signals from camera operation members (not shown) are detected by the switch operation unit 117 and sent to the camera MPU 101.

  The strobe control unit 118 performs light emission processing such as a light emission mode (selecting flash light emission or flat light emission), a light emission pattern (pre-light emission instruction or main light emission instruction), a main light emission amount, and the like. In addition, an auto bounce drive instruction or the like in the present invention is also performed. The camera MPU 101 communicates with the built-in flash 119 via the flash control unit 118. The camera MPU 101 communicates with the strobe 200 via the strobe control unit 118 and the external strobe connection unit 120.

(Structure of strobe)
Next, the configuration of the strobe 200 will be described with reference to the block diagram of FIG. 5 and the external view of the external strobe of FIGS. In the present embodiment, as shown in FIG. 6, description will be made on an external strobe attached to the camera. Here, the strobe main body unit 201, the bounce mechanism unit 202, the strobe head unit 203, the light emitting unit 205, and the camera connection unit 210 shown in the block diagram of FIG. 5 respectively correspond to the external views of FIGS. .

  First, the structure of the strobe will be described with reference to the block diagram of FIG. A strobe body 201 includes a main board (not shown), a battery box (not shown), and a power switch and various operation members 213 and a display 214 shown in FIG. Etc. are stored.

  Reference numeral 202 denotes a bounce mechanism that stores a head angle detector 208 (not shown), a main capacitor (not shown), and the like. The bounce mechanism unit 202 is an irradiation direction variable means of a known method in the external strobe 200, and holds the strobe head unit 203 so as to be rotatable with respect to the strobe body unit 201 in the horizontal direction and the vertical direction, respectively. It is possible to perform bounce shooting with different strobe emission directions. Reference numeral 203 denotes a strobe head unit, which stores a light emitting unit 205, which will be described later, necessary for strobe light emission.

  Reference numeral 204 denotes a strobe microcontroller (hereinafter referred to as a strobe MPU) for controlling the system such as a light emission control sequence. Selection and control of light emission modes such as flash light emission and flat light emission, light emission amount control, light emission intensity and light emission time of flat light emission. Control and so on. The strobe MPU 204 also performs system control such as control of the light emission angle and determination of the angle of the strobe head unit during auto bounce drive control.

  Further, in the present embodiment, the strobe MPU 204 is a light emission condition setting means for setting light emission modes such as flash light emission and flat light emission, and light emission conditions such as a zoom position set in a zoom driving unit 206 described later. The strobe MPU 204 is an appropriate exposure condition calculation unit that calculates an appropriate value for a setting related to exposure based on an exposure condition acquired from the camera 100 described later and the light emission condition. The strobe MPU 204 is a light emission distance calculation unit that calculates a light emission distance based on a ceiling distance measured by a distance measuring photometry unit 207 described later and a subject distance.

  A light emitting unit 205 in the strobe head unit 203 is a light emitting unit that performs flash light emission and flat light emission, and includes a strobe light emission circuit (not shown) that emits strobe light in accordance with a light emission signal from the strobe MPU 204. The light emitting unit 205 includes a discharge tube such as a xenon tube (not shown) required for strobe light emission, a reflector, a Fresnel lens, and the like.

  A zoom drive unit 206 is a strobe irradiation range changing unit using a known method, and includes a drive motor, a lead screw, and the like (not shown). Based on the control signal from the camera MPU 204, the zoom driving unit 206 drives the xenon tube and the reflector of the light emitting unit 205 to change the illumination range of the emitted light of the strobe light emission, so Irradiation can be performed with strobe light emission that matches the focal length of the illustrated photographic lens.

  A distance measuring photometry unit 207 is a distance measuring unit in the present embodiment. The distance measuring photometry unit 207 reflects the strobe light emitted from the light emitting unit 205 to the object to be measured, receives the reflected light by a distance measuring photometric sensor (not shown), and outputs it to the strobe MPU 204. The strobe MPU 204 converts this luminance signal by an A / D converter (not shown), and calculates a distance corresponding to the conversion amount. Note that the photometry unit for distance measurement 207 measures the distance to the ceiling and the distance to the subject in auto bounce drive control, which is a known method.

Reference numeral 208 denotes a head angle detection unit, which is a rotation angle detection sensor composed of a substrate having a known phase pattern and a contact brush, and a relative rotation angle of the strobe head unit 203 with respect to the strobe body unit 201 during bounce shooting. Is output to the strobe MPU 204. As shown in FIG. 7, the head angle detection unit 208 sets the rotation angle at the bounce around the Y axis with respect to the normal position where the strobe head unit 203 faces the object field (head unit angle 0 °). The part angle θ _A and the rotation angle at the bounce around the X axis are detected as the vertical head part angle θ _B.

Here, in this embodiment, as the detected angle, the horizontal head portion angle θ _A is θ _A = −90 ° in the direction in which the head portion faces left as viewed from the photographer, as shown in FIG. The direction to become θ _A = + 90 °, the direction toward the shooting side is assumed to be θ _A = ± 180 ° (−180 ° when rotating to the left, + 180 ° when rotating to the right), and the vertical head The part angle θ _B will be described assuming that the direction in which the head part faces upward as seen from the photographer is θ _B = + 90 ° as shown in FIG.

In the strobe device according to the present embodiment, as shown in FIG. 7, the movable range of the strobe head unit by the bounce mechanism unit 202 is
Horizontal head portion angle θ _A : −180 ° to + 180 °
Vertical head angle θ _B : 0 to 120 °
And

  Reference numeral 209 denotes a bounce drive control unit, which is an irradiation direction drive unit in the present embodiment. The bounce drive control unit 209 can drive the strobe head unit 203 in the horizontal and vertical directions with respect to the strobe body unit 201 by controlling a motor (not shown) according to a signal from the strobe MPU 204.

  Reference numeral 210 denotes a connection portion with the camera. The camera communicates with the camera via the camera connection unit 210. As shown in FIG. 8, reference numeral 211 denotes an attitude detection unit that obtains the inclination γ in the pitch direction and the inclination η in the roll direction of the strobe body unit 201 based on the horizontal position (normal position) of the camera. Here, as shown in FIG. 8, the inclinations γ and η are detected by detecting the angle of inclination with the clockwise rotation as + and the counterclockwise rotation as −.

  Reference numeral 212 denotes a head unit angle calculation unit, which is an irradiation direction determination unit in the present embodiment. Upon receiving an instruction from the flash MPU 204, the head angle calculation unit 212 receives a command from the distance metering unit 207 and the data acquired by the posture detection unit 211, and the head unit of the strobe for optimal bounce shooting Calculate the angle.

  Reference numeral 213 denotes an operation member which sets parameters necessary for controlling the strobe by the user's operation. Reference numeral 214 denotes a display unit that displays each state of the strobe 200 to the user.

(Operation (flow chart))
The operation of the first embodiment of the present invention will be described below with reference to FIGS. Note that the process shown in FIG. 2 is a shooting operation process performed under the control of the camera MPU 101, and the process shown in FIGS. 1 and 3 is an auto bounce drive executed under the control of the flash MPU 204. It is a process of control operation.

  First, FIG. 2 is a flowchart showing a procedure of photographing processing executed by the camera 100 of FIG. In step S201, the SW1 state of the switch operation unit 117 is detected. If it is ON, the process proceeds to step S202. If it is OFF, the state detection of SW1 is continued. In step S <b> 202, the camera MPU 101 performs distance measurement using the focus detection unit 115. The lens control unit 114 performs autofocus control, and performs focus detection processing for controlling the focus lens to the in-focus position.

In step S203, the camera MPU 101 performs a photometric operation using the photometric unit 112, and acquires a photometric result. For example, when the photometric sensor 113 of the photometric unit 112 performs photometry in each of the divided areas, the camera MPU 101 sets the brightness value of each area as an obtained photometric result as EVb (i) (i = 0 to 5). )
Is stored in the buffer memory 106.

  In step S204, the camera MPU 101 performs exposure calculation using a known algorithm based on the photometric result (the luminance value stored in the buffer memory 106) acquired in step S203 and the set shooting mode. A shutter control value (Tv value), an aperture control value (Av value), and a gain setting value (ISO sensitivity) are set as various exposure conditions, and an exposure value (EV) is determined.

  In step S205, the camera MPU 101 communicates an auto bounce drive instruction to the strobe 200 via the strobe control unit 118. In step S206, the camera MPU 101 notifies the exposure condition (Tv value, Av value, ISO sensitivity value) calculated in step S204 to the strobe 200 via the strobe control unit 118.

  In step S207, the camera MPU 101 checks for an auto bounce end notification from the strobe 200. If the bounce drive end notification transmitted in step S305 from the strobe 200, which will be described later, has been acquired, the process proceeds to step S208 as auto bounce end, and if not acquired, the check of the auto bounce end notification is continued.

  In step S208, it is detected whether or not SW2 (not shown) of the switch operation unit 117 is pressed. If it is ON, the process proceeds to step S210. If it is OFF, the process proceeds to step S209. In step S209, similarly to step S201, whether or not SW1 is continuously pressed is detected. If ON, the process returns to step S207 to continue checking SW2, and if OFF, the process returns to step S201.

  In step S210, strobe preliminary light emission processing is performed. First, the camera MPU 101 instructs the flash control unit 118 to perform preliminary (pre) light emission. The strobe control unit 118 communicates a pre-flash instruction with a predetermined amount of light to the strobe, and strobe emission is started. The camera MPU 101 calculates the main flash emission amount at the time of exposure based on the luminance signal at the time of the preliminary (pre) emission.

  Next, in step S211, the motor control unit 110 controls the motor according to the signal from the camera MPU 101 to raise the mirror (not shown). In step S212, accumulation in the image sensor 103 is started. In step S213, the shutter control unit 111 is instructed to run and open a shutter (not shown) to start exposure of the image sensor 103.

  In step S214, strobe main light emission processing is performed. The camera MPU 101 instructs the flash control unit 118 to perform main flash based on the flash main flash amount obtained in step S210. Then, the strobe control unit 118 communicates a main light emission instruction with a predetermined light amount to the strobe, and strobe light emission is started. The camera MPU 101 performs an exposure operation under predetermined exposure conditions (Av value, Tv value, ISO sensitivity value) in synchronization with the strobe light emission.

  In step S215, the camera MPU 101 instructs the shutter control unit 111 to close the shutter, and in the next step S216, the accumulation of the image sensor 103 is ended.

  In step S217, the camera MPU 101 instructs the motor control unit 110 to lower the mirror (not shown) to the imaging optical path.

  In step S 218, the image signal is read from the image sensor 103 and the image data processed by the A / D conversion unit 104 is temporarily stored in the buffer memory 106. When all the image signals are read from the image sensor 103, a predetermined development process is performed on the image signals to create image data.

  In step S219, the created image data is recorded as an image file in the storage medium 109 via the storage medium I / F 108, and the series of shooting processes is completed.

(Strobe auto bounce drive control)
Next, the auto bounce drive control process executed based on the control of the strobe MPU 204 in the strobe 200 of FIG. 5 will be described using the flowchart of FIG. In the flowchart in the present embodiment, the strobe body 201 is described as having no inclination (inclination γ = 0 °, inclination η = 0 ° in step S101 described later), and when the strobe body 201 has an inclination. An example of auto bounce driving will be described later.

  First, in step S <b> 101, the strobe MPU 204 detects the pitch direction inclination γ and the roll direction inclination η of the strobe body unit 201 by the posture detection unit 211. In step S102, the flash MPU 204 checks an auto bounce instruction notification from the camera. If the auto bounce instruction notification transmitted in step S205 from the camera side has been acquired, the process proceeds to step S103, and if not acquired, the process returns to step S101 to continue the posture detection and auto bounce instruction check.

  In step S103, the flash MPU 204 acquires the camera exposure conditions (Tv value, Av value, ISO sensitivity value) transmitted in step S206 from the camera side.

  In step S104, the flash MPU 204 determines the GNo., Which is the amount of light at the time of photographing based on the Tv value of the exposure condition acquired in step S103 and the flash emission condition. Calculate the value. Here, the flash emission conditions are the flash GNo. This is the setting of the strobe 200 for changing the value, that is, the flash mode or the flat flash mode, and the zoom position of the light emitting unit 205 driven by the zoom driving unit 211. These light emission conditions are arbitrarily set by the photographer, or automatically set by the camera MPU 101 or the strobe MPU 204 according to the exposure conditions of the camera 100 and the lens focal length.

  Here, depending on the light emission mode and the zoom position which are the light emission conditions of the strobe, Gno. A description of changing the value will be given. First, according to FIG. 10, Gno. Is the amount of strobe light emitted to the subject by strobe light emission when shooting with the camera 100 according to the light emission mode of flash light emission or flat light emission and the Tv value of the exposure condition. Explain that the value changes.

  First, FIGS. 10A and 10B are diagrams when the strobe 200 emits flash light, and FIGS. 10C and 10D are diagrams when the strobe 200 is controlled to emit light with flat light emission. It is. 10 (a) and 10 (c) are the respective light emission modes. As the shutter operation performed under the control of the shutter control unit 111 when an instruction is issued from the camera MPU 101, the vertical axis represents the SH front curtain and the post SH SH. The curtain position and the horizontal axis of the curtain are represented by time. The curtain positions are the positions of the SH front curtain and the SH rear curtain with respect to the image sensor 103. As an example, FIGS. 10A and 10C illustrate the SH front curtain and the SH rear screen from the upper side to the lower side of the image sensor 103. This shows the curtain running in the order of the curtain. (B) and (d) of FIG. 10 show the operation of light emission control by the flash MPU 204 in the respective light emission modes, the vertical axis indicates the light emission amount, and the horizontal axis indicates the time axis.

  In the case of flash emission control as shown in FIGS. 10A and 10B, the shutter speed at the time of flash emission is up to 1/200 or 1/250 at which the flash emission can be synchronized. Setting. In this case, strobe light emission is performed with flashing light as shown in FIG. 10B at the timing of the fully opened state where the front curtain and rear curtain of the shutter are fully opened as shown in FIG. In the case of flash emission as shown in the figure, the shutter speed is limited, but it is possible to emit light with the maximum amount of light that the strobe 200 can emit.

  On the other hand, as shown in FIGS. 10C and 10D, when the strobe 200 emits flat light, the shutter speed setting is 1/8000, and the shutter speed is higher than a numerical value such as a synchronization speed 1/250. Setting is possible. However, as shown in FIG. 10C, in the case of a high-speed shutter operation, the so-called slit travel is performed between the SH front curtain and the SH rear curtain, not in the fully open state. In that case, when flash emission as shown in FIG. 10B is performed, the brightness of a photograph taken with strong light hitting only a part of the image sensor 103 is uneven.

  Therefore, as shown in FIG. 10 (d), a flat light emission of a known method for emitting light at a constant brightness from the traveling of the front curtain of the SH to the completion of the traveling of the rear curtain of SH is performed. In flat light emission, it is necessary to continue to emit light with the same amount of light for a certain period of time from the time when the SH front curtain travel is completed to the time after the SH rear curtain travel is completed. It will decrease.

  Furthermore, as the Tv value, which is the shutter speed, increases with respect to the maximum light amount at the time of flat light emission, the exposure time of the image sensor 103 is shortened, so that the amount of light that is captured by flat light emission is reduced. It will become. As an example, Gno. In the strobe 200 having a value of about 40, when the light emission mode becomes flat light emission and the Tv value becomes 1/320 (about 3.1 msec), the Gno. When the value is about 17.6 and the Tv value is 1/8000 (about 0.13 msec), Gno. The value is about 3.5.

  Next, Gno. An explanation of the change in value will be given. The zoom driving unit 206 is a known strobe irradiation range changing unit, and moves a xenon tube (not shown) or a reflector of the light emitting unit 205 to a predetermined zoom position according to the lens focal length. Then, at the zoom position adjusted to the focal length on the telephoto side (Tele) of the lens, the irradiation range at the time of flash emission becomes narrow, and Gno. The value gets bigger. On the other hand, when the zoom position is set in accordance with the focal length on the wide angle side (Wide) of the lens, the irradiation range at the time of flash emission becomes wide, and Gno. The value is low.

  In step S105, the flash MPU 204 obtains the Gno. Based on the value and the exposure condition (Av value, ISO sensitivity value) of the camera acquired in step S103, the optimum shooting distance d at which the light emitted by the flash emission reaches the subject is determined.

And is temporarily stored in the internal memory of the strobe MPU 204.

  In step S106, the flash MPU 204 determines whether or not the optimum shooting distance d with the strobe light emission calculated in step S105 is equal to or less than a predetermined distance n. If it is equal to or less than the predetermined distance n, the process proceeds to step S107. If the distance d is greater than the predetermined distance n, the process proceeds to step S108. Here, the predetermined distance n is set as a numerical value such as 0.5 m or 1 m, for example. By doing so, when the result of the optimum shooting distance d calculated in step S105 is a short distance of 0.5 m or 1 m or less and bounce shooting toward the ceiling direction, the irradiation light of the strobe clearly does not reach the subject. It is possible to prevent it from becoming a failed photo.

Step S107 is bounce drive control of a subroutine to be described later. The strobe MPU 204 sets the target value of the head part angle of the strobe head part 202 as the horizontal direction target head part angle θ _X and the vertical direction target head part angle θ _Y. . Here, in step S106, since it is determined that there is a high possibility that light does not reach the subject in the bounce shooting, in order to perform strobe shooting in the front direction of the imaging device,
θ _X = 0 °, θ _Y = 0 °
Will be set. In step S107, the distance measurement in step S304 of a subroutine described later is not performed.

Step S108 is a bounce drive control of a subroutine to be described later. The strobe MPU 204 sets the target value of the head portion angle of the strobe head portion 202 as the horizontal direction target head portion angle θ _X and the vertical direction target head portion angle θ _Y. . Here, it is a bounce drive for measuring the subject, and in order to face the front direction of the imaging device,
θ _X = 0 °, θ _Y = 0 °
Will be set. In step S108, the distance measuring photometry unit 207 measures the subject distance p and temporarily stores it in the internal memory of the flash MPU 304.

In step S109, the flash MPU 204 compares the optimum shooting distance d calculated in step S105 with the object distance p measured in step S108 multiplied by a predetermined coefficient μ.
Optimal shooting distance d> μ × subject distance p (2)
If so, the process proceeds to step S110 in order to continue the ceiling distance measurement and the like in the auto bounce drive control. When the expression (2) is not satisfied, the process proceeds to step S107 in order to stop the operation in the auto bounce drive control.

  Here, the predetermined coefficient μ in the expression (2) is an optimum shooting distance d considering that the distance is always longer than the subject distance p in order to irradiate the subject by reflecting off the ceiling or the like when performing bounce photography. Is a value set so that the distance becomes longer than the subject distance p with a predetermined margin. For example, when performing bounce shooting, it is assumed that the ceiling distance is at least 0.5 m or more. Further, based on the measurement result in step S108, the subject distance p = 1 m. Then, the calculation of the bounce head portion angle θ and the calculation of the optical path length L, which are obtained in steps S111 and S112, which will be described later with reference to FIG. 9, are performed from the light emitting unit 205 of the strobe by the equations (3), (4), and (5). The optical path length L of the main light beam 213 is assumed to be about 1.5 m.

  Therefore, when μ = 1.5 and the subject distance p = 1 m is multiplied, it is determined whether or not the optimum shooting distance d is larger than 1.5 m, and whether or not the subject can be irradiated even if bounce shooting is considered. Can be determined. Then, it is determined whether or not to perform auto bounce drive for distance measurement in the ceiling direction in the subsequent step S110, and it becomes possible to eliminate the bounce operation in unnecessary auto bounce drive control.

  Also, in actual bounce shooting, the ceiling often has a reflectance of 60% or 70%, so that the light irradiated by the bounce emission is attenuated, and μ = 2.0 or 2.5 You may set by value.

Step S110 is a bounce drive control of a subroutine which will be described later. Here, the strobe MPU 204 performs horizontal target head angle θ _X , as a drive for measuring the distance to the ceiling, which is a reflector at the time of bounce shooting. perform bounce driving target vertical target head unit theta _Y, a step of measuring the distance to the ceiling. Therefore, when the camera 100 has no tilt, the strobe 200 has no tilt and the tilt acquired in step S101 is γ = 0 ° and η = 0 °, and the ceiling direction is θ _X = 0 ° and θ _Y = 90 °. Will be set. In step S110, the ceiling distance h is measured and temporarily stored in the internal memory of the strobe MPU 304.

Here, an example of the horizontal direction target head portion angle θ _X and the vertical direction target head portion angle θ _Y set as the drive target when the strobe 200 detects the tilt in step S101 will be described. In step S101, the pitch direction inclination γ = + 10 ° and the roll direction inclination η = 0 ° are detected. In step S103, the horizontal head portion angle θ _A = 180 ° and the vertical head portion angle θ _B = It is assumed that 70 ° is acquired. On the basis of the result, here, the direction of the ceiling directly above is set as the horizontal target head angle θ _X = 180 ° and the vertical target head angle θ _Y = (90−10) = 80 ° according to the inclination. The setting is made and bounce drive is performed.

  In step S111, the flash MPU 204 uses the head angle calculation unit 212 to set the bounce head from the tilt, subject distance p, and ceiling distance h obtained in steps S101, S108, and S110. The angle θ is obtained and temporarily stored in the internal memory of the strobe MPU 204.

Here, the example of the calculation method of bounce head part angle (theta) is given. Like the example of the bounce shooting scene shown in FIG. 9A, the subject distance to the subject P starting from the strobe light exit surface of the strobe head unit 203 is p, the ceiling distance to the ceiling is h, the subject P is Let p1 be the distance from the ceiling reflecting surface at the time of bounce to the intersection with the vertical line, and p2 be the distance from the intersection to the strobe light exit surface of the strobe head unit. The angle formed by the main light beam 213 of the light emitted from the light emitting unit 205 at the time of bounce is defined as a bounce head unit angle θ with reference to the front direction in which the light emitting unit 205 of the strobe is directed to the optical axis direction of the photographing lens. Here, since there is no inclination of the strobe body 201, γ = 0 ° and η = 0 °. Therefore, a horizontal target head angle θ _X , a vertical target head angle θ _Y , which will be described in a later-described subroutine, Are set as θ _X = 0 ° and θ _Y = θ.

  Then, assuming that the angle at which the main light beam 213 is reflected by the ceiling and enters the subject is the subject incident angle α, p2 is

Is required. Also, from equation (3), the bounce head angle θ is

Thus, the bounce head portion angle θ for realizing the subject incident angle α is determined by the above equation (4).

  Here, since the subject incident angle α is a preset constant, the subject distance p and the ceiling distance h are detected by the distance measuring photometry unit 207 in step S304, which will be described later, so that the bounce head unit angle θ can be calculated. Become. For example, when the subject incident angle α = 30 °, the subject distance p = 3 m, and the ceiling distance h = 1.5 m, the bounce head portion angle θ is about 75 °. Similarly, as shown in FIG. 9B, in the case where the subject P and the photographer photographed at a relatively close distance, for example, the subject incident angle α = 30 °, the subject distance p = 2m, When the ceiling distance h is 1.5 m, the result of Expression (3) is negative, θ on the left side of Expression (4) is (180 + θ), and the bounce head portion angle θ is about 112 °. .

  In step S111, as shown in FIG. 9, assuming that the subject P is a person, the subject incident angle α of the reflected light emitted by the strobe light is calculated with an optimum angle of 30 °. This is because when the subject incident angle α is a large value such as 60 ° or 70 °, the light is almost directly above the person and a shadow may appear on the hair or chin of the person. Accordingly, when it is known by image recognition or the like that the subject is not a person, the subject incident angle may be set to a value other than 30 °.

In step S112, the flash MPU 204 determines that the bounce head unit angle θ calculated in step S111 is θ> τ (5) with respect to the predetermined angle τ.
If the expression (5) is satisfied, the process proceeds to step S113. If not satisfied, the process proceeds to S107. In step S112, when the bounce head portion angle θ is smaller than a predetermined angle, the emitted light at the time of strobe emission directly enters the field of photography to prevent a bright and unnatural photograph from appearing only in the upper part of the field. It is a judgment of. Therefore, in a condition where the emitted light is likely to enter directly (θ ≦ τ), bounce shooting is not performed, and driving is performed so that the irradiation direction of the light emitting unit 205 of the strobe 200 is directed to the front direction of the shooting optical axis. The predetermined angle τ is set in consideration of the angle of view of the lens and the light distribution angle of the strobe light. However, it is desirable that the predetermined angle τ is set at an angle of 40 ° or 45 ° with a sufficient margin.

  In step S113, the bounce limit distance limL is obtained by calculation. Here, the limL defined as the bounce limit distance is obtained from the camera exposure conditions obtained in S103, the subject distance p obtained in S108 and S110, the ceiling distance h, the amount of light attenuation by reflecting the ceiling, and the like. This is the value of how much light reaches the direction of the subject under the bounce condition.

  Here, the calculation method of the bounce limit distance limL will be described using the flowchart of FIG. In S600, the optical path length L is obtained. The strobe MPU 204 is based on the subject distance p and the ceiling distance h detected in steps S108 and S110, the bounce head portion angle θ calculated from the equations (3) and (4) in step S111, and the set subject incident angle α. The optical path length L is calculated and temporarily stored in the internal memory of the strobe MPU 204.

Here, an example of a method for calculating the optical path length L will be described with reference to FIG. First, as shown in FIG. 9A, the distance to the reflecting surface of the ceiling of the main luminous flux 213 of the light emitted from the light emitting unit 205 of the strobe head unit 203 is A, and the distance to the subject after the reflection of the ceiling is shown. B. The distances A and B are A = h / Sinθ (6)
B = h / Sinα (7)
The optical path length L is L = A + B (8)
It can be calculated by. For example, as shown in FIG. 9A in step S111, when the subject incident angle α = 30 ° and the bounce head portion angle θ calculated with the ceiling distance h = 1.5 m is about 75 °, A = 1. .55 m, B = 3 m, and L = 4.55 m.

  In S601, the distance light quantity attenuation rate dL is obtained by calculation. Here, the attenuation rate of the light quantity due to the difference between the distance p in the case where light is emitted directly to the subject without bounce and the distance of the optical path length L in the case of bounce obtained in S600 is obtained by the following equation.

dL = (p / L) ^ 2
In S602, the ceiling reflection attenuation rate dB is acquired. Here, by reflecting the strobe light on the ceiling, the strobe MPU 204 acquires two attenuations, which are a light amount attenuation due to the reflectance of the ceiling and a light amount attenuation due to the diffusion of the light, as fixed values in advance. . Here, assuming that the reflectance of the ceiling is 50%, and the attenuation factor due to light diffusion is 1 / π, the ceiling reflection attenuation factor dB is approximately −2.6 steps when expressed by the number of steps.

  In S603, the head angle attenuation rate dH is acquired from the table. This head angle attenuation rate indicates the attenuation rate of the amount of light that varies depending on the head angle. The reason that the attenuation rate of the strobe light quantity changes depending on the head angle is that the ceiling is made an ideal diffusion surface in S602. However, the attenuation factor changes because the specular reflection component actually increases and decreases depending on the head angle. It is done.

  A table of the head angle and the head angle attenuation rate dH is shown in FIG. As shown in the table of FIG. 12, when the head angle is directed toward the subject, the light quantity attenuation rate decreases. 9A and 9C, the distance of the optical path length A + B is the same, but the head angle θ is tilted toward the subject side from (a) to (c). In this case, bounce is caused. The attenuation rate of the light quantity is (a)> (c).

In S604, frPv of Gno at the time of bounce is obtained by calculation. The various light quantity attenuation coefficients obtained in S601 to S603 are added to the direct shot Gno obtained in S104. In the following formula, Gno and various light quantity attenuation coefficients are converted into a log scale and used.
frPV = Gno + dL + dB + dH
In S605, the bounce limit distance limL is obtained by calculation. As described above, the limL defined as the bounce limit distance is obtained by the following equation based on the camera exposure conditions obtained in S103 and the bounce time Gno obtained in S604. LimL is a value indicating how much light reaches the direction of the subject under this bounce condition.

Bounce time limit distance = frPV + ISO sensitivity value−Av value As described above, S600 to S605 are specific methods for obtaining the bounce time limit distance limL. Returning to the flow of FIG. In step S114, the flash MPU 204 compares the optimum shooting distance d calculated in step S105 with the bounce time limit distance limL calculated in step S605.

Optimum shooting distance d> Bounce limit distance limL (9)

If so, it is determined that the bounce shooting at the bounce head portion angle θ calculated in step S111 is possible, and the process proceeds to step S115. If the equation (9) is not satisfied, the bounce head portion angle θ as it is. Then, it is determined that the amount of light is insufficient in the bounce shooting, and the process proceeds to step S116.

  With this operation, it is possible to perform optimum flash photography that prevents a photographer's unintentional photograph from being generated due to insufficient light emission amount of the flash emitted to the subject during bounce photography.

Step S115 is a bounce drive control of a subroutine, which will be described later. The strobe MPU 204 drives the strobe head unit 202 to the bounce head unit angle θ calculated in step S111 or step S118, and a horizontal target head unit angle θ _X. performs bounce drive control based on the vertical target head angle theta _Y. After the bounce drive in step S115 is completed, the process proceeds to step S120.

  In step S116, the flash MPU 204 calculates an optimal ISO sensitivity value and an optimal Av value that satisfy the equation (10). One of ISO sensitivity value and Av value may be fixed and the other may be calculated, or both may be changed.

Optimum shooting distance d> frPV + optimum ISO sensitivity value−optimum Av value (10)
In step S117, the flash MPU 204 causes the display unit 214 to display “warning display, appropriate exposure condition setting value information”. Here, the appropriate exposure condition setting value information is the optimum ISO sensitivity value or the optimum Av value calculated in step S116.

  In step S118, the flash MPU 204 acquires the current ISO sensitivity value and Av value information from the camera MPU 101, and checks whether the setting has been changed. If changed, the process proceeds to step S119, and if there is no change, step S117 is continued.

  In step S119, the flash MPU 204 acquires the current ISO sensitivity value and Av value information from the camera MPU 101, and checks whether or not the expression (11) is satisfied.

Optimum shooting distance d> frPV + current ISO sensitivity value−current optimum Av value (11)
If it is satisfied, it is determined that bounce shooting is possible, and the process proceeds to step S120. If not satisfied, step S117 is continued.

  In step S120, the flash MPU 204 deletes the “warning display and appropriate exposure condition setting value information” displayed on the display unit 214, and proceeds to step S112. Thus, the user can know that the bounce shooting is possible.

  As described above, even when a bounce photograph causes a failed photograph due to insufficient light quantity, even by a novice user, the setting can be easily changed by displaying “warning display, appropriate exposure condition setting value information” on the display unit 214. It becomes possible.

  In step S <b> 121, the flash MPU 204 checks a light emission instruction notification from the camera MPU 101. If the light emission pattern (preliminary light emission instruction or main light emission instruction) and the predetermined light emission amount transmitted in steps S210 and S214 from the camera MPU 101 side are acquired, the process proceeds to step S122. If not, the light emission instruction notification is checked. Continue.

  In step S122, the flash MPU 204 performs light emission control according to the light emission pattern (preliminary light emission instruction or main light emission instruction) and a predetermined light emission amount. In step S123, the flash MPU 204 returns to step S121 to continue to perform main flash control if the flash pattern acquired from the camera in step S121 is preliminary flash, and if the acquired flash pattern is flash, The control process ends.

In steps S110 to S120 in the present embodiment, the description has been made on the assumption that there is no inclination. Actually, however, the inclinations γ and η of the strobe main body 200 obtained in step S101 are the same as described in step S110. Based on the above, the bounce head portion angle θ and the horizontal direction target head portion angle θ _X and the vertical direction target head portion angle θ _Y that are target values for realizing the bounce head portion angle θ are set.

(Bounce drive control subroutine)
Next, details of the bounce drive control in subroutine steps S107, S108, S110, and S115 will be described with reference to the flowchart of FIG. The process shown in FIG. 3 is a bounce drive operation process executed under the control of the flash MPU 204.

First, in step S301, the strobe MPU 204 controls a motor (not shown) by the bounce drive control unit 209 and starts driving the strobe head unit 203. In step S302, the stroboscopic MPU 204 acquires the current horizontal head part angle θ _A and vertical head part angle θ _B of the current stroboscopic head position from the head angle detection unit 208, and the acquired current head part angle is It is checked whether the horizontal target head portion angle θ _X and the vertical target head portion bounce angle θ _Y are matched. If they match θ _X = θ _A and θ _Y = θ _B , the process proceeds to step S303, and if they do not match, the check of whether they match is continued.

Here, the horizontal direction target head portion angle θ _X and the vertical direction target head portion angle θ _Y are values set as driving in the ceiling direction in step S110 shown in FIG. Similarly, the horizontal target head angle θ _X and the vertical target head angle θ _Y are set as θ _X = 0 ° and θ _Y = 0 ° as driving in the front direction in steps S107 and S108. Value. Similarly, the horizontal direction target head portion angle θ _X and the vertical direction target head portion angle θ _Y are calculated in steps S111 and S118 as the bounce head portion angle θ in step S115, and the inclination γ, It is a value set according to η.

  In step S303, the strobe MPU 204 controls the motor by the bounce drive control unit 209 and stops driving the strobe head unit 203. In step S304, the strobe MPU 204 measures the distance to the ceiling in the step S110 shown in FIG. 1, and measures the distance to the subject in step S108. There are various methods for measuring the distance, such as a triangulation method and a laser distance measurement. Here, the distance is measured by the amount of light of the reflector by the light emitted by the strobe light.

  Specifically, strobe light is emitted from the light emitting unit 205 by the pre-flash of the strobe 200, reflected by the object, the reflected light is received by the distance measuring photometry unit 207, and output to the strobe MPU 204. The strobe MPU 204 converts this luminance signal by an A / D converter (not shown), calculates a distance according to the conversion amount, and temporarily stores it in the internal memory of the strobe MPU 204. This step is executed by performing communication only at steps S108 and S110.

  In step S305, the flash MPU 204 communicates a bounce drive end notification to the camera via the camera connection unit 210. In this step, communication is performed at steps S107 and S115.

  With the control method in the present embodiment described above, in auto bounce drive control during bounce shooting, based on exposure conditions (Av value, Tv value, ISO sensitivity value, etc.) and light emission conditions (light emission mode, zoom position, etc.), It was determined whether appropriate bounce shooting is possible with the current camera exposure condition settings (Tv value, Av value, ISO sensitivity value, etc.). As a result, even if the bounce light does not reach the subject, it is possible for a novice user to easily change the setting by displaying “warning display, appropriate exposure condition setting value information” on the display unit 214. Become.

  In the present embodiment, in the calculation of the optimum shooting distance d, bounce head unit angle θ, and optical path length L, the posture detection on the strobe side, the data acquired by the photometry unit for distance measurement, and the strobe side received from the camera side. The flash MPU 204 calculates the exposure conditions (Tv value, Av value, ISO sensitivity value). However, data (exposure conditions, subject distance, etc.) acquired by the photometry unit, lens control unit, posture detection unit, etc. on the camera side, light emission conditions (Gno. Value, etc.) received from the strobe side by the camera side, ceiling distance, etc. The camera MPU 101 may calculate based on the above.

  Furthermore, in the present embodiment, the strobe MPU 204 on the strobe side controls the auto bounce drive and the drive instruction to the predetermined target drive head unit angle, but the camera side communicates the state of the external strobe to the camera side. The MPU 101 may perform control of auto bounce drive and drive instruction to a predetermined target drive head unit angle.

  In this embodiment, after the optimum ISO sensitivity value and the optimum Av value are calculated, “warning display, appropriate exposure condition setting value information” is displayed on the display unit 214. However, the camera MPU 101 is operated to set the camera. May be automatically changed to an appropriate value.

101 Camera MPU
103 Image sensor 105 Memory controller 106 Buffer memory 110 Motor control unit 111 Shutter control unit 112 Photometric unit 113 Photometric sensor 115 Focus detection unit 116 Attitude detection unit 117 Switch operation unit 118 Strobe control unit 119 Built-in strobe 120 External strobe connection unit 200 External strobe 201 Strobe body 202 Bounce mechanism 203 Strobe head 204 Strobe MPU
205 Light Emitting Unit 206 Zoom Driving Unit 207 Distance Measuring Photometric Unit 208 Head Angle Detection Unit 209 Bounce Drive Control Unit 210 Camera Connection Unit 211 Posture Detection Unit 212 Head Unit Angle Calculation Unit 213 Operation Member 214 Display Unit

Claims (4)

An imaging system comprising: an imaging device; and an illumination device built in or attached to the imaging device,
The imaging apparatus has an exposure condition setting means capable of setting an exposure condition,
A light emitting means for irradiating the photographic field with light;
An irradiation direction variable means for moving a movable portion including the light emitting means to change the light irradiation direction of the light emitting means;
An irradiation direction drive means for changing the irradiation direction of light of the light emitting means by automatically driving the irradiation direction variable means;
An irradiation direction determining means for determining an irradiation direction of light to be driven by the irradiation direction driving means;
A light emission condition setting means capable of setting a light emission condition for determining the exposure condition;
Distance measuring means capable of measuring a subject distance between a subject to be imaged and the lighting device, and a ceiling distance between a ceiling and the lighting device;
Display means for notifying the user of information,
An appropriate exposure condition calculating unit that calculates an appropriate value of the setting related to exposure from the subject distance measured by the distance measuring unit and the exposure condition set by the exposure condition setting unit;
An imaging system, wherein the appropriate value calculated by the appropriate exposure condition calculating means is displayed on the display means.   After the appropriate value calculated by the appropriate exposure condition calculating means is displayed on the display means, the display content of the display means is changed when the exposure condition is changed by the exposure condition setting means. The imaging system according to claim 1.   After the appropriate value calculated by the appropriate exposure condition calculating means is displayed on the display means, when the exposure condition is changed by the exposure condition setting means to satisfy the appropriate value, the display means The imaging system according to claim 1, wherein display content is changed. An imaging system comprising: an imaging device; and an illumination device built in or attached to the imaging device,
The imaging apparatus has an exposure condition setting means capable of setting an exposure condition,
A light emitting means for irradiating the photographic field with light;
An irradiation direction variable means for moving a movable portion including the light emitting means to change the light irradiation direction of the light emitting means;
An irradiation direction drive means for changing the irradiation direction of light of the light emitting means by automatically driving the irradiation direction variable means;
An irradiation direction determining means for determining an irradiation direction of light to be driven by the irradiation direction driving means;
A light emission condition setting means capable of setting a light emission condition for determining the exposure condition;
Distance measuring means capable of measuring a subject distance between a subject to be imaged and the lighting device, and a ceiling distance between a ceiling and the lighting device;
Display means for notifying the user of information,
An appropriate exposure condition calculating unit that calculates an appropriate value of the setting related to exposure from the subject distance measured by the distance measuring unit and the exposure condition set by the exposure condition setting unit;
An imaging system, wherein the exposure condition setting means is operated to automatically change to an appropriate value calculated by the appropriate exposure condition calculation means.