JP4429150B2 - Strobe shooting system, strobe device and camera - Google Patents

Description

  The present invention relates to a strobe photographing system, a strobe device, and a camera.

  In general, an irradiable lens focal length is used to show the irradiation angle characteristic of a strobe. For example, a 35 mm lens cover is displayed. This indicates that, assuming that the screen size is 135 film, the irradiation characteristics of a strobe device (hereinafter also simply referred to as a strobe) cover an angle of view of about 38 ° up and down and about 54 ° left and right. However, the amount of light at the angle above (about 19 degrees), below (about 19 degrees), left (about 27 degrees), and right (about 27 degrees) the strobe light emitting unit is not illuminated uniformly. Indicates only that it is satisfied that the amount of light on the light emission optical axis of the strobe is minus one step (the amount of light is 50%) or more.

Here, the square frame in FIG. 14 represents the shooting screen. The distribution of the amount of light actually radiated on the photographing screen is not defined as a decrease in the amount of light in the diagonal direction, and is also influenced by the so-called cosine fourth law, and the amount of light decreases with increasing distance from the center. The number of steps indicating the contour lines indicates a drop in the amount of light emitted from the strobe from the center of the screen. As is apparent from FIG. 14, there are cases where the drop in the amount of light at the four corners of the shooting screen is two or more. Therefore, there is no particular problem when the subject is in the vicinity of the center of the screen, but when the subject is located in the periphery of the screen, the exposure is underexposed and a good photographing result may not be obtained. Further, when the zoom state of the lens with a zoom function is set to the wide-angle side, or when a lens configured to widen the angle of view is used, the amount of light is likely to drop. In particular, an electronic still camera has a narrow dynamic range of an image pickup device as compared with a film camera, and there has been a problem in that the amount of strobe light around the screen is reduced. Patent Document 1 has already proposed a technique for compensating for the influence of such a light loss. The technique disclosed in Patent Document 1 includes a light amount distribution correction table that corrects captured data based on a light amount distribution at the time of photographing using a strobe, and corrects the imaged data by the light amount distribution correction table. It is to do.
JP 2003-87653 A

  However, when the light amount drop correction is performed using the conventional technique of Patent Document 1, the exposure is corrected to an appropriate value, but the image quality is not improved. This is due to the fact that the linearity of the image sensor at the site corrected using the light amount distribution correction table is poor and proper correction is not performed. This drop in image quality due to the drop in light intensity is not at the level that users are worried about when shooting with general image quality, but it may be that some users are concerned about shooting with higher image quality. It is done.

(Object of invention)
An object of the present invention is to provide a strobe photographing system, a strobe device, and a camera capable of photographing at an appropriate irradiation angle at the time of photographing using a strobe.

In order to achieve the above object, a strobe shooting system according to the present invention includes an imaging unit that images a subject, an image quality selection unit that selects a recording quality of an image captured by the imaging unit, and focal length information of a shooting lens. Setting means for setting an irradiation angle of strobe light based on the recording image quality selected by the image quality selection means, and when the setting means has the same focal length information of the photographing lens, the image quality selection means The higher the selected recording image quality, the wider the flash light irradiation angle is set .

Similarly, in order to achieve the above object, a strobe device according to the present invention is a stroboscopic device that can be attached to and detached from a camera that includes an imaging unit that captures an image of an object and an image quality selection unit that selects a recording quality of an image captured by the imaging unit. And a setting unit that sets an irradiation angle of the strobe light based on the focal length information of the photographing lens and the recording image quality selected by the image quality selecting unit, and the setting unit includes a focal point of the photographing lens. When the distance information is the same, the higher the recording image quality selected by the image quality selection means, the more the strobe light irradiation angle is set to the wide angle side .

Similarly, in order to achieve the above object, a camera according to the present invention includes an imaging unit that images a subject, an image quality selection unit that selects a recording quality of an image captured by the imaging unit, focal length information of the imaging lens, and the Setting means for setting an irradiation angle of the strobe light based on the recording image quality selected by the image quality selection means, and the setting means is selected by the image quality selection means when the focal length information of the photographing lens is the same The higher the recorded image quality is, the more the irradiation angle of the strobe light is set to the wide angle side .

  According to the present invention, it is possible to provide a strobe photographing system, a strobe device, or a camera capable of photographing at an appropriate irradiation angle at the time of photographing using a strobe.

  The best mode for carrying out the present invention is as shown in Examples 1 to 6 described below.

  FIG. 1 is a block diagram showing a circuit configuration of a flash photographing system according to Embodiment 1 of the present invention. In the figure, 1 is a camera, 2 is a lens that can change the focal length that can be attached to and detached from the camera 1, and 3 is a strobe (strobe device) that can change the irradiation angle of strobe light.

  First, the configuration in the lens 2 will be described. Reference numeral 4 denotes a photographing lens capable of changing the focal length, and reference numeral 5 denotes an aperture. Reference numeral 6 denotes a lens control unit which controls the aperture 5 with the aperture value obtained from the camera 1, controls the taking lens 4 in order to adjust the focus according to an instruction from the camera 1, and sets focal length information of the taking lens 4. This is transmitted to the camera 1. The above exchange of information between the camera 1 and the lens 2 is performed via a terminal 15 composed of a plurality of terminals.

Next, the configuration inside the camera 1 will be described. Reference numeral 7 denotes a shutter. Reference numeral 8 denotes an image sensor, which is controlled by a system control unit 14 described later. An image processing unit 9 processes a signal corresponding to a subject image from the image sensor 8 according to an instruction from the system control unit 14 and sends the processed signal to a buffer memory 10 described later. A buffer memory 10 temporarily stores a signal processed by the image processing unit 9 according to an instruction from the system control unit 14 and outputs the signal to a memory control unit 11 described later as a signal according to an instruction from the system control unit 14. Reference numeral 11 denotes a memory control unit, which is a signal from the buffer memory 10 with an image size (having large, middle, and small sizes) and a compression rate (having normal and low compression rate fines) input by an input unit 17 described later. Are processed and output to the external memory 13 described later, and the processed content is stored in the external memory 13. Further, the memory control unit 11 can read out image information stored in the external memory 13 according to an instruction from the system control unit 14 and display an image on the display unit 18 described later. A connection terminal 12 connects the external memory 13 and the memory control unit 11. A system control unit 14 controls the entire camera system. Reference numeral 17 denotes an input unit constituting image quality selection means, which can select a recording image quality (specifically, image size or compression rate) of a captured image and input various camera modes. Reference numeral 18 denotes a display unit which can display image quality, various camera modes, and images. Reference numeral 19 denotes an operation unit, which includes a plurality of switches, and includes at least a power switch, a release switch, and the like (not shown). Reference numeral 16 denotes a terminal on the camera 1 side, which transmits a signal to the strobe 3 and includes a plurality of terminals.

  Next, the configuration inside the strobe 3 will be described. Reference numeral 20 denotes a terminal provided on the strobe 3, which transmits a signal to the camera 1 and is composed of a plurality of terminals. Reference numeral 21 denotes a strobe system control unit, which controls an irradiation angle of a light emitting unit 24 described later, light emission control, display by a strobe display unit 23 described later, and the like. A strobe input unit 22 can set a mode related to an irradiation angle. Reference numeral 23 denotes a strobe display unit constituted by an LCD, which can display focal length information, guide numbers, various modes, and the like. A light emitting unit 24 moves the light emitting unit 24 back and forth with respect to the Fresnel lens 25 as indicated by an arrow 26 in accordance with an instruction from the strobe system control unit 21 to control the irradiation angle. The strobe system control unit 21 and the light emitting unit 24 correspond to irradiation angle variable means.

  Next, the operation of the flash photographing system configured as described above will be described in detail with reference to FIGS.

  First, the setting time of the image size and the compression rate of the captured image of the camera 1 will be described with reference to the flowchart of FIG.

  Step S101 is a power-on state of the camera 1, and when it is detected in step S102 that the user has selected the image size / compression rate selection mode by an operation button (not shown) of the operation unit 19, the next step In S103, the image size selected by the input unit 17 is set. There are three types of image sizes, large, middle, and small. Here, it is assumed that the large size is selected. Further, the compression rate selected by the input unit 17 is set. There are two types of compression ratios, low compression ratio fine and high compression ratio normal. Here, it is assumed that fine is selected. When the setting of the selected image size / compression rate selection mode is completed, the image size / compression rate selection mode is canceled (step S104), and the process returns to the start state (step S105). As described above, the screen size and the compression rate at this time are in the state set in step S103.

  Next, the photographing operation of the camera 1 will be described with reference to FIG.

  Step S111 is a state in which the image size and the compression rate described in FIG. From this state, the process proceeds to step S112, where it is determined whether the switch SW1 that is turned on by half-pressing a shutter button (not shown) is turned on. Thereafter, when the switch SW1 is turned on, the process proceeds to step S113, where it is determined whether or not a light emission preparation completion signal is input from the strobe 3. If it is in the light emission preparation complete state, the process proceeds to step S114 and is not in the light emission preparation complete state. If so, go to Step S122.

If the strobe 3 is ready for light emission and the process proceeds to step S114, the focal length of the taking lens 4 is input from the lens 1. Here, the focal length of the photographic lens 4 is 36 mm . In step S 115, the focal length “36 mm” of the photographing lens 4 is output to the strobe 3. In the next step S116, the fact that the image size is “large size” is output to the flash unit 3. In the subsequent step S117, the fact that the compression rate is “fine” is output to the flash unit 3.

  In the next step S118, the shutter speed and aperture value used for AE (automatic exposure) are determined by a photometric means (not shown). Further, the in-focus state is controlled by an auto focus (AF) means (not shown). Then, in the next step S119, it is determined whether or not the switch SW2 that is turned on by fully pressing a shutter button (not shown) is turned on. If it is off, the process waits until the switch SW2 is turned on. Thereafter, when the switch SW2 is turned on, the process advances to step S120 to execute the flash photographing operation and store the captured image data in the external memory 13. Then, in the next step S121, the series of operations is terminated.

If it is determined in step S113 that the strobe 3 is not ready for light emission, the process proceeds to step S122, and a photographing process using natural light (details are not directly related to the present invention and will not be described ) is executed. In step S123, the series of operations is terminated.

  Next, the operation of the strobe 3 will be described with reference to the flowchart of FIG. 2C and FIG.

  Step S201 is a state in which a power switch (not shown) of the strobe 3 is turned on, charging of a main capacitor for light emission (not shown) is started, and a light emission preparation completion signal has already been output to the camera 1. In this state, first, the focal length information of the photographing lens 4 is input from the camera 1 in step S202. Here, the focal length of the taking lens 4 is 36 mm. In the next step S203, the display focal length according to a table (not shown) holding the contents of FIG. 3 in the strobe system control unit 21 is displayed on the strobe display unit 23. That is, since the focal length of the photographic lens 4 is 36 mm, 35 mm is displayed on the strobe display unit 23 from FIG. The contents of FIG. 3 will be described in detail later.

  In the next step S204, the image size is input from the camera 1. Here, the image size is a large size. In the subsequent step S205, the compression rate is input from the camera 1. Here, the compression ratio is fine. In step S206, information on the image size and the compression rate is displayed on the strobe display unit 23. Although not shown, “Large” and “Fine” are displayed. In the next step S207, the control irradiation angle is read from the table. The control irradiation angle is a lens focal length that allows the user to maintain an image quality that does not bother the user from worrying about a drop in the amount of peripheral light due to flash irradiation when high image quality is not required. Since the image size is large and the compression rate is fine, the image quality mode is set and 28 mm is read out. In subsequent step S208, since the guide number at the irradiation angle of 28 mm is “30”, “30” is displayed on the strobe display unit 23. However, at this time, the display focal length of the strobe display unit 23 is not changed. In the next step S209, the light emitting unit 24 is controlled to have an irradiation angle corresponding to 28 mm. In step S210, light emission and light emission control are performed in accordance with the light emission instruction from the camera 1, and a series of operations is terminated in the next step S211.

  Here, the contents shown in FIG. 3 will be described below.

  The lens focal length at the left end in FIG. 3 is focal length information of the photographing lens 4 received by the strobe 3 from the camera 1. The display focal length is the focal length displayed on the strobe display unit 23, and the focal length of the photographing lens 4 or the focal length on the wider side is displayed. This is useful for the photographer to know the rough lens focal length at the time of photographing. Further, since the control irradiation angle is controlled stepwise, the display focal length also changes stepwise. The controlled irradiation angle is an irradiation angle of a strobe that is actually controlled, and is a generally defined irradiation angle as described above. In the low image quality mode, the display focal length and the control irradiation angle coincide with each other since the generally defined irradiation angle is controlled with respect to the display focal length. Note that the guide number changes in accordance with the control irradiation angle, and the larger the value of the control irradiation angle, the narrower the irradiation angle and the larger the guide number. The guide number changes according to the sensitivity of the image sensor 8, but the sensitivity is constant in FIG.

  As is clear from FIG. 3, the higher the image quality, the smaller the focal length that can be covered by the control irradiation angle than the focal length of the photographing lens 4, and the wider the irradiation angle. Obtainable.

  Further, in each image quality mode, if the irradiation angle cannot be appropriately controlled in accordance with the focal length of the photographic lens 4, the display focal length display on the strobe display unit 23 blinks to warn. The case where “warning” is written in parentheses after the numerical value of the display focal length in FIG. 3 corresponds to the above. In FIG. 3, the display focal length is displayed stepwise, but the focal length of the photographic lens 4 may be displayed as it is. Further, although the control irradiation angle is controlled stepwise, it may be controlled continuously.

  Next, a flash photographing system according to Embodiment 2 of the present invention will be described. Note that the circuit configuration of the flash photography system is the same as that of the first embodiment (FIG. 1). The operation of the camera 1 is the same as that in the flowcharts of FIGS. 2A and 2B in the first embodiment, and a description thereof will be omitted.

  The operation of the strobe 3 in Embodiment 2 of the present invention will be described with reference to the flowchart of FIG. 4 and FIG.

  Step S301 is a state in which a power switch (not shown) of the strobe 3 is turned on, charging of a light emission main capacitor (not shown) is started, and a light emission preparation completion signal has already been output to the camera 1. From this state, the process proceeds to step S302, and the focal length information of the photographing lens 4 is input from the camera 1. Here, the focal length of the taking lens 4 is 36 mm. In the next step S303, the image size is input from the camera 1. Here, the image size is a large size. In the subsequent step S304, the compression rate is input from the camera 1. Here, the compression ratio is fine. In the next step S305, the display focal length according to a table (not shown) holding the contents of FIGS. 5A and 5B in the flash system control unit 21 is displayed on the flash display unit 23. . That is, since the focal length of the photographing lens 4 is 36 mm and the image quality mode is set, 35 mm is displayed on the strobe display unit 23 from FIG. FIG. 5 will be described in detail later.

  In the next step S306, information on the image size and the compression ratio, that is, “large” and “fine” are displayed on the strobe display unit 23. In subsequent step S307, the focal length correction value is read from the table, the focal length correction value is added to the lens focal length, and the control irradiation angle is determined from the addition result. Here, as can be seen from FIG. 5B, since the lens focal length is 36 mm and the focal length correction value is −5 mm, the corrected focal length is 31 mm, and the corresponding control irradiation angle is 28 mm. It is determined. In the next step S308, the guide number “25” at the control irradiation angle of 28 mm is read from the table and displayed on the strobe display unit. However, at this time, the display focal length information of the strobe display unit 23 is not changed. In the next step S309, the light emitting unit 24 is controlled to have a control irradiation angle corresponding to 28 mm. In step S310, light emission and light emission control are executed in accordance with the light emission instruction from the camera 1, and in a next step S311, a series of operations is terminated.

  Next, the contents shown in FIG. 5 will be described.

  FIG. 5A is a diagram applied in the normal image quality mode, and FIG. 5B is a diagram applied in the high image quality mode. The lens focal length is a focal length of the photographing lens 4 sent from the camera 1 to the strobe 3. The display focal length is the focal length displayed on the strobe display unit 23, and the focal length of the photographing lens 4 or the focal length on the wider side is displayed. This helps the photographer to know the rough lens focal length at the time of shooting. Further, since the control irradiation angle is controlled stepwise, the display focal length is also set to change stepwise. The control irradiation angle is an irradiation angle of a strobe that is actually controlled, and indicates an irradiation angle that is generally defined as described above. In the normal image quality mode, the display focal length is controlled to the generally defined irradiation angle, so that the display focal length matches the control irradiation angle. Note that the guide number changes in accordance with the control irradiation angle, and the larger the value of the control irradiation angle, the narrower the irradiation angle and the larger the guide number. The guide number changes according to the sensitivity of the image sensor 8, but the sensitivity is constant in FIG.

  As is clear from FIG. 5, in the high image quality mode, the focal length that can be covered by the control irradiation angle is smaller in the high image quality mode than in the normal image quality mode. That is, the irradiation angle becomes wide. Therefore, the high image quality mode is less affected by the decrease in the amount of peripheral light, and an image with better image quality can be obtained.

  Further, in each image quality mode, if the irradiation angle cannot be appropriately controlled in accordance with the focal length of the photographic lens 4, the display focal length display on the strobe display unit 23 blinks to warn. In FIG. 5, the case where “warning” is written in parentheses after the numerical value of the display focal length corresponds to the above. In FIG. 5, the display focal length is displayed stepwise, but the focal length of the photographic lens 4 may be displayed as it is. Further, although the control irradiation angle is controlled stepwise, it may be controlled continuously.

  Next, a flash photographing system according to Embodiment 3 of the present invention will be described. Note that the circuit configuration of the flash photography system is the same as that of the first embodiment (FIG. 1). The operations in steps S401 to S405 related to the setting of the image size and compression rate of the captured image shown in FIG. 6A by the camera 1 are the same as the flowchart of steps S101 to S105 in FIG. Since it is the same, the description is abbreviate | omitted.

  First, the photographing operation with the camera 1 according to the second embodiment of the present invention will be described with reference to the flowchart of FIG.

  Step S411 is a state in which the image size and the compression rate are set by the operation in FIG. From this state, the process proceeds to step S412, where it is determined whether the switch SW1 that is turned on by half-pressing a shutter button (not shown) is turned on. Thereafter, when the switch SW1 is turned on, the process proceeds to step S413, where a light emission preparation completion signal is input from the strobe 3 and if the light emission preparation complete state is entered, the process proceeds to step S414, and if not, the process proceeds to step S423.

  If the strobe 3 is ready for light emission and the process proceeds to step S414, the focal length of the taking lens 4 is input from the lens 1. Here, the focal length of the taking lens 4 is 36 mm. In step S415, the focal length 36 mm of the photographing lens 4 is output to the strobe 3. In the next step S416, the focal length correction value is read from a table (not shown) in the system control unit 14 of the camera 1 according to the image quality mode determined by the image size and the compression rate, and the focal length correction value is output to the strobe 3. . It is assumed that the contents of FIG. 5A and FIG. 5B are held in the table. Here, since the lens focal length is 36 mm, the image size is “large”, and the compression rate is “fine”, it is a high image quality mode, and the focal length correction value is −5 mm. This value is output to the strobe 3. In the subsequent step S417, the fact that the image size is a large size is output to the flash unit 3. In the next step S418, the fact that the compression ratio is fine is output to the flash unit 3.

  In the next step S419, the shutter speed and aperture value used for AE are determined by a photometric means (not shown). Further, the in-focus state is controlled by an autofocus means (not shown). Then, in the next step S420, it is determined whether or not the switch SW2 that is turned on when the shutter button (not shown) is fully pressed is turned on, and if it is off, the process waits until the switch SW2 is turned on. Thereafter, if the switch SW2 is turned on, the process proceeds to step S421, where the flash photographing operation is executed and the captured image data is stored in the external memory 13. Then, in the next step S422, a series of operations is terminated.

  If it is determined in step S413 that the strobe 3 is not ready for light emission, the process proceeds to step S423, where photographing processing using natural light (details are not directly related to the present invention and description thereof is omitted) is executed. In step S424, the series of operations is terminated.

  Next, the operation of the strobe 3 will be described with reference to the flowchart of FIG.

  Step S501 is a state in which the power switch (not shown) of the strobe 3 is turned on, charging of the main capacitor for light emission (not shown) is started, and a light emission preparation completion signal has already been output to the camera 1. In this state, first, the focal length information of the photographing lens 4 is input from the camera 1 in step S502. Here, the focal length of the taking lens 4 is 36 mm. In the next step S503, the corrected focal length described in step S416 in FIG.

  In the next step S504, the image size is input from the camera 1. Here, the image size is a large size. In the subsequent step S505, the compression rate is input from the camera 1. Here, the compression ratio is fine. In the next step S506, the strobe display unit 23 displays the image size and the compression ratio, that is, “large” and “fine”. In the next step S507, the display focal length according to a table (not shown) holding the contents of FIGS. 5A and 5B in the strobe system control unit 21 is displayed on the strobe display unit 23. That is, since the focal length of the photographing lens 4 is 36 mm and the image quality mode is set, 35 mm is displayed on the strobe display unit 23 from FIG.

  In the next step S508, the focal length “36 mm” input in step S502 and the focal length correction value “−5 mm” input in step S503 are added to obtain a corrected focal length. Here, the corrected focal length is 31 mm, and the control irradiation angle is determined to be 28 mm correspondingly. In subsequent step S509, the guide number at the control irradiation angle of 28 mm is “25” as shown in FIG. 5B, so that this is displayed on the strobe display unit 23. However, at this time, the display focal length information of the strobe display unit 23 is not changed. Then, in the next step S510, the light emitting unit 24 is controlled to have a control irradiation angle corresponding to 28 mm. In subsequent step S511, light emission and light emission control are performed in accordance with the light emission instruction from the camera 1, and a series of operations is terminated in step S512.

  The difference between the third embodiment and the second embodiment described above is that the focal length correction value is read by the strobe 3 in the second embodiment (step S307 in FIG. 4), and the camera 1 in the third embodiment is used. The data is being read (step S416 in FIG. 6). As a result, the content displayed on the strobe display unit 23 and the controlled irradiation angle are exactly the same. The description of FIG. 5A and FIG. 5B is the same as that of the second embodiment described above, and is omitted here.

  Next, a flash photographing system according to Embodiment 4 of the present invention will be described. Note that the circuit configuration of the flash photography system is the same as that of the first embodiment (FIG. 1). The operation of the camera 1 is the same as that in the flowcharts of FIGS. 2A and 2B in the first embodiment, and a description thereof will be omitted.

  The operation of the strobe 3 in Embodiment 4 of the present invention will be described with reference to the flowchart of FIG. 7 and FIG.

  Step S601 is a state in which the power switch (not shown) of the strobe 3 is turned on, charging of the main capacitor for light emission (not shown) is started, and a light emission preparation completion signal has already been output to the camera 1. From this state, the process proceeds to step S602, and the focal length information of the photographing lens 4 is input from the camera 1. Here, the focal length information of the photographing lens 4 is 36 mm. In the next step S603, since the lens focal length is 36 mm according to the table (not shown) holding the contents shown in FIGS. 8A and 8B in the strobe system control unit 21, the display focal length is set to 35 mm. The information is displayed on the strobe display unit 23. FIG. 8 will be described later. In a succeeding step S604, the image size is input from the camera 1. Here, the image size is a large size. In step S605, the compression rate is input from the camera 1. Here, the compression ratio is fine.

  In the next step S606, a shift step corresponding to the lens focal length is read from the table. Here, since the image quality mode is selected, the focal length is 36 mm, so the shift step is -1. In the normal image quality mode, in the case of 36 mm, the irradiation angle is controlled by the 35 mm cover, but since the shift step is −1, the irradiation angle is controlled by a 28 mm lens cover shifted by one step to the wide angle side. In the subsequent step S607, the guide number is read from the table and displayed. Here, since the control irradiation angle is a 28 mm cover, the guide number is “25”. In the next step S608, the irradiation angle is controlled by the control irradiation angle of the 28 mm cover according to the table. In the subsequent step S609, light emission and light emission control are performed in accordance with the light emission instruction from the camera 1, and a series of operations are terminated in step S610.

  Here, the contents of FIGS. 8A and 8B will be described. FIG. 8A shows a lens focal length in the normal image quality mode, a display focal length, a shift step, a control irradiation angle, and a guide number displayed on the strobe display unit 23 of the strobe 3 corresponding thereto. In the normal image quality mode, the image size / compression rate is small / normal, small / fine, middle / fine, and middle / normal. As is apparent from FIG. 8A, the irradiation angle is controlled stepwise. The shift step indicates how many steps the control irradiation angle with respect to the display focal length is shifted in the normal image quality mode, and naturally the shift step is 0 in the normal image quality mode.

  FIG. 8B shows the display focal length, the shift step, the control irradiation angle, and the guide number with respect to the lens focal length in the high image quality mode in which the image size / compression ratio is large / fine. As is clear from FIG. 8B, the shift step is -1 in the high image quality mode, which is one step wide-angle side compared to when using a lens having the same focal length as in the normal image quality mode. It can be seen that it is controlled by the irradiation angle.

Here, the shift step in the high image quality mode is set to only -1, but the shift step can be changed according to the focal length of the photographing lens 2. It is also possible to provide a low image quality mode, a medium image quality mode, and a high image quality mode as image quality modes and change the shift step according to the image quality mode.

  Also in the fourth embodiment, when a lens having the same focal length is used in the high image quality mode as compared with the normal image quality mode, the irradiation angle is controlled to the wide angle side, so that an image with good image quality can be obtained. .

  Next, a flash photographing system according to Embodiment 5 of the present invention will be described. Note that the circuit configuration of the flash photography system is the same as that of the first embodiment (FIG. 1). Further, since the operation relating to the setting of the image size and compression rate of the photographed image by the camera 1 is the same as that in FIG. 2A in the first embodiment, the description thereof is omitted.

  First, the photographing operation with the camera 1 in Embodiment 5 of the present invention will be described with reference to the flowchart of FIG.

  Step S701 is a state in which the image size and the compression rate are set. From this state, the process proceeds to step S702, where it is determined whether the switch SW1 that is turned on by half-pressing a shutter button (not shown) is turned on. Thereafter, when the switch SW1 is turned on, the process proceeds to step S703. Here, a light emission preparation completion signal is input from the strobe 3, and if the light emission preparation is complete, the process proceeds to step S704, and if not, the process proceeds to step S710.

  If the strobe 3 is ready for light emission and the process proceeds to step S704, the focal length of the taking lens 4 is input from the lens 1. Here, the focal length of the taking lens 4 is 36 mm. In step S705, the focal length of the photographing lens 4 is output to the strobe 3. As described above, it is 36 mm here. In the next step S706, the shutter speed and aperture value used for AE are determined by a photometric means (not shown). Further, the in-focus state is controlled by an autofocus means (not shown). In a succeeding step S707, it is determined whether or not the switch SW2 that is turned on when the shutter button (not shown) is fully pressed is turned on. If it is turned off, the process waits until the switch SW2 is turned on. Thereafter, when the switch SW2 is turned on, the process advances to step S708 to execute the flash photographing operation and store the captured image data in the external memory 13. Then, in the next step S709, the series of operations is terminated.

  If it is determined in step S703 that the strobe 3 is not ready for light emission, the process advances to step S710 to execute a photographing process using natural light (details are not directly related to the present invention, so the description is omitted). In step S711, the series of operations is terminated.

  Next, the operation of setting the irradiation angle mode with the strobe 3 will be described with reference to the flowchart of FIG.

  Step S801 is a state in which a power switch (not shown) of the strobe 3 is turned on. From this state, the process proceeds to step S802, and if it is detected by the user that the setting mode of the irradiation angle mode is selected by the strobe input unit 22, the process proceeds to step S803, and the irradiation angle mode selected by the strobe input unit 22 is set. . The irradiation angle mode has a normal mode and a high image quality mode. Here, the high image quality mode is set on the assumption that the high image quality mode has been selected, and the high image quality mode is displayed on the strobe display unit 23. When the normal mode is selected, the irradiation angle mode need not be displayed. In step S804, the setting mode of the irradiation angle mode is canceled, and in the next step S805, the state at the start is returned.

  Next, the operation of the strobe 3 will be described with reference to the flowchart of FIG. 9C and FIG.

  Step S811 is a state in which the power switch (not shown) of the strobe 3 is turned on, charging of the main capacitor for light emission (not shown) is started, and a light emission preparation completion signal has already been output to the camera 1. As described above, the irradiation angle mode is set to the high image quality mode. From this state, the process proceeds to step S812, and the focal length information of the photographing lens 4 is input from the camera 1. Here, the focal length information of the photographing lens 4 is 36 mm. In the next step S813, the display focal length in the strobe 3 is displayed on the strobe display unit 23 according to a table (not shown) holding the contents shown in FIGS. 10A and 10B in the strobe system control unit 21. To do. At this time, since the focal length of the photographic lens 4 is 36 mm, a lens having a display focal length of 35 mm is displayed from FIG.

  In the next step S814, the guide number 25 is displayed on the strobe display unit 23 according to the table. Then, in the next step S815, the control irradiation angle is controlled to the 28 mm lens cover according to the table. In the subsequent step S816, light emission and light emission control are performed in accordance with the light emission instruction from the camera 1, and a series of operations are terminated in the next step S817.

  Here, the contents of FIGS. 10A and 10B will be described. FIG. 10A shows the normal mode, and the display focal length displayed on the strobe display unit 23 corresponding to the lens focal length, which is the focal length of the photographing lens 4, is generally defined. The control irradiation angle and the guide number corresponding to the control irradiation angle are shown. For example, when the focal length of the photographic lens 4 is 25 mm, the display focal length is 24 mm, and 24 mm and the guide number 23 at that time are displayed on the strobe display unit 23. When the focal length of the photographic lens 4 is 20 mm, the display focal length is 24 mm, but since the controllable irradiation angle is up to 24 mm, the display of 24 mm blinks, and it is photographed that the flash cannot properly illuminate the subject. Alert the person.

  FIG. 10B shows the high image quality mode. The display focal length, the control irradiation angle, and the control displayed on the strobe display unit 23 corresponding to the lens focal length which is the focal length of the photographing lens 4 are shown. The guide number corresponding to the irradiation angle is indicated. In FIG. 10B, when the lens focal length is 25 mm or less, the display focal length is 24 mm, and 24 mm displayed on the strobe display unit 23 blinks and warns as in the description of FIG.

  As is clear from FIGS. 10A and 10B, when the high image quality mode is selected with the flash 3, the irradiation angle is wider than that in the normal mode even with the same lens focal length, and better image quality can be obtained. Is solved. As described above, the table in the strobe system control unit 21 is created so as to realize FIG. 10A and FIG. 10B.

  As is apparent from the flow of FIG. 9 described above, the image quality mode of the strobe 3 can be selected according to the image quality set in the camera 1. Also, the image quality mode can be set regardless of the image quality set by the camera 1. For example, even if the camera 1 is in the high image quality mode, the normal mode can be set if priority is given to the guide number.

  Next, a strobe shooting system according to Embodiment 6 of the present invention will be described. Note that the circuit configuration of the flash photography system is the same as that of the first embodiment (FIG. 1).

  The sixth embodiment of the present invention focuses on an exposure system in which the ratio of exposure between strobe light and natural light is changed by natural light luminance in strobe shooting. In general, in the exposure system as described above, the ratio of strobe light is larger as the natural light is lower in luminance, and is 100% in the dark. In addition, the higher the luminance, the larger the ratio of natural light, and the lower the ratio of strobe light, the lower it is 40% or less. As a matter of course, the lower the luminance is, the larger the ratio of strobe light, the more conspicuous the drop in the amount of light around the shooting screen. On the other hand, in the case of high brightness, the drop in the amount of light around the shooting screen becomes inconspicuous due to natural light.

  As described above, in the sixth embodiment of the present invention, the flash photographing system prioritizes the irradiation angle over the guide number when the natural light has a low luminance, and prioritizes the guide number over the irradiation angle as the luminance increases.

  The operation of the camera 1 according to the sixth embodiment of the present invention will be described with reference to the flowchart of FIG. 11A and FIG.

  Step S901 is a state in which the image size and the compression rate are set by the operation in FIG. From this state, the process proceeds to step S902, where it is determined whether the switch SW1 that is turned on by half-pressing a shutter button (not shown) is turned on. Thereafter, when the switch SW1 is turned on, the process proceeds to step S903. Here, a light emission preparation completion signal is input from the strobe 3. If the light emission preparation complete state is entered, the process proceeds to step S904, and if not, the process proceeds to step S913.

  If the strobe 3 is ready for light emission and the process proceeds to step S904, the focal length of the taking lens 4 is input from the lens 1. Here, the focal length of the photographic lens 4 is 31 mm, and the focal length of 31 mm of the photographic lens 4 is output to the strobe 3 in step S905. In the next step S906, the natural light luminance is measured by a photometric means (not shown). The measurement result is an apex value of BV2. In the subsequent step S907, the contribution ratio to the exposure amount of the strobe light emission is determined based on a table (not shown) holding the contents shown in FIGS. 12A and 13 in the system control unit. Details of the contribution ratio of the strobe light to the natural light luminance are as shown in FIG. Since the ratio of the strobe light is BV2, the numerical value is 70% to 75%.

  In the next step S908, the focal length correction value is output to the strobe from the table. Since the natural light luminance is BV2, the focal length correction value is 31 mm × 0.15 = 4.65. In the subsequent step S909, the shutter speed and aperture value used for AE are determined based on the external light luminance. Further, the in-focus state is controlled by an autofocus means (not shown). In step S910, it is determined whether the switch SW2 that is turned on when the shutter button (not shown) is fully pressed is on. If it is off, the process waits until the switch SW2 is turned on. Thereafter, when the switch SW2 is turned on, the process advances to step S911 to execute a flash photographing operation and store the imaged image data in the external memory 13. As described above, the contribution ratio of strobe light is controlled at 75%. Then, in the next step S712, a series of operations is terminated.

  If it is determined in step S903 that the strobe 3 is not ready for light emission, the process proceeds to step S913, where a photographing process using natural light (details are not directly related to the present invention and description thereof is omitted) is executed. In step S914, the series of operations is terminated.

  Next, the operation of the strobe 3 will be described with reference to the flowchart of FIG. 11B and FIG.

  Step S1011 is a state in which the power switch (not shown) of the strobe 3 is turned on, charging of the main capacitor for light emission (not shown) is started, and a light emission preparation completion signal has already been output to the camera 1. From this state, the process proceeds to step S1012, and the focal length information of the photographing lens 4 is input from the camera 1. Here, the focal length of the photographic lens 4 is 31 mm. In the next step S1013, the focal length information of the photographing lens 4 is displayed on the strobe display unit 23. In the subsequent step S1014, a focal length correction value is input. The focal length correction value is 4.65 mm as described above.

  In the next step S1015, the focal length correction value is subtracted from the focal length of the photographic lens 4 to calculate the corrected focal length. The calculation result is 31−4.65 = 26.25 (mm). Then, the control irradiation angle is determined according to FIG. 12B of a table (not shown) in the strobe system control unit 21. The determined control irradiation angle is 26 mm. In the subsequent step S1016, a guide number corresponding to the control irradiation angle is displayed on the strobe display unit 23. Here, “29” is displayed. At this time, when the corrected focal length is 23 mm or less, since it is out of the range of the irradiation angle control, the displayed focal length blinks and warns. In the next step S1017, the irradiation angle is controlled according to the determined control irradiation angle. In subsequent step S1018, light emission and light emission control are performed in accordance with the light emission instruction from camera 1, and in step S1019, a series of operations is terminated.

  Next, the contents of FIGS. 12A and 12B will be described.

  In FIG. 12A, the luminance is the natural light luminance measured by the photometric means (not shown) of the camera 1, and the strobe light contribution rate is uniquely determined with respect to the natural light luminance. As shown in FIG. 13, for example, the brightness is set in the system control unit 14 in the camera 1 so that the brightness BV2 (apex value) is 75% and the brightness BV5 is 50%. The focal length correction value is less than the lens focal length × 0.15 (mm) when the strobe light contribution rate is very low and less than the luminance BV3. The focal length correction value is BV3 or more and less than BV6 where the strobe light contribution rate is relatively high. Lens focal length × 0.075 (mm). Further, the focal length correction value is 0 (mm) at BV6 or higher where the contribution ratio of strobe light is low. When the focal length correction value is subtracted from the lens focal length, the corrected focal length shown in FIG. The control irradiation angle is determined according to the corrected focal length, and the guide number is also determined.

  In the above flow, the case where the lens focal length is 31 mm and BV2 is described. However, when the lens focal length is 31 mm and BV4, the focal length correction value is 31 × 0.075 = 2.325 mm, and the corrected focal length is 28. It becomes 675 mm, and the control irradiation angle becomes 28 mm. Therefore, it can be seen that the control irradiation angle becomes wider as the luminance decreases, that is, the contribution ratio of the strobe light increases.

  In the sixth embodiment, the focal length correction value is determined by the camera and sent to the strobe. However, the natural light luminance information may be received from the camera and the focal length correction value may be determined by the strobe.

  The effects of the first to sixth embodiments will be described collectively below.

  (1) It has means for changing the flash light irradiation angle according to the focal length information of the photographing lens 4 and means for selecting the shooting image quality, and changes the flash light irradiation angle according to the selection result of the shooting image quality. Like to do. Therefore, it is possible to perform strobe shooting at an appropriate irradiation angle according to the shooting image quality. Specifically, when high image quality is selected by the means for selecting the shooting image quality, the shooting angle is changed so that the irradiation angle is wide (wide angle). Obtainable.

  (2) It has means for changing the irradiation angle of the strobe light according to the focal length information of the photographing lens 4 and means for selecting the photographing image quality, and the focal length information of the photographing lens 4 according to the selection result of the photographing image quality Is corrected by a predetermined amount. Therefore, it is possible to perform strobe shooting at an appropriate irradiation angle according to the shooting image quality. Specifically, when the high image quality is selected by the means for selecting the photographic image quality, the focal length information of the photographic lens 4 is corrected to the wide side. In this case, the irradiation angle is set to the wide side. Therefore, it is possible to obtain a good photographing result with less light loss around the screen. The camera 1 corrects the focal length information of the photographing lens 4 according to the selection result of the image quality, and transmits the corrected focal length information to the strobe 3. Alternatively, the strobe 3 responds to the selection result of the image quality. The focal length information of the photographing lens 4 from the camera 1 is corrected.

  (3) A means for changing the irradiation angle of the strobe light according to the focal length information of the photographing lens 4 and a means for selecting the photographing image quality. Shift). Therefore, it is possible to perform strobe shooting at an appropriate irradiation angle according to the shooting image quality. Specifically, when the high image quality is selected by the means for selecting the shooting image quality, the shooting image quality is shifted to the wide side, so that it is possible to obtain a good shooting result with less light loss around the screen. .

  (4) In the flash photographing system of (1) to (3), the image quality selected by the photographing image quality selecting means is an image size or a compression rate. Therefore, it is possible to perform flash photography at an appropriate irradiation angle according to the image size or compression rate.

  (5) In a strobe device having means for changing the flash light irradiation angle according to the focal length information of the photographing lens 4 and means for selecting an image quality mode, the irradiation angle is changed according to the selected image quality mode. I am doing so. Therefore, it is possible to change the irradiation angle of the strobe light according to the image quality mode, and when a strobe shooting system including the strobe device is configured, the flash photography can be performed at an appropriate irradiation angle according to the shooting image quality. It becomes possible.

  (6) Means for controlling the irradiation angle of the strobe light in accordance with the focal length of the photographing lens 4, means for measuring the external light luminance (natural light luminance), and determining the strobe light contribution rate based on the result of the natural light luminance And correcting the irradiation angle of the strobe light controlled in accordance with the focal length of the photographic lens 4 based on the determination result of the strobe light contribution rate. Therefore, it is possible to appropriately change the irradiation angle of the strobe light according to the contribution ratio to the exposure of the strobe light. Specifically, the strobe light irradiation angle is corrected to the wide side as the strobe light contribution rate is higher according to the determination result of the strobe light contribution rate. Therefore, uneven irradiation of strobe light at low luminance can be reduced.

  In the first to sixth embodiments, the control irradiation angle is determined by the strobe system control unit 21, but the present invention is not limited to this. The camera has a plurality of control irradiation angle tables instead of the strobe, and the control irradiation angle is determined by selecting the table according to the strobe to which the system control unit 14 of the camera is mounted. A configuration for transmitting to the system control unit 21 may be employed.

  In addition, although a description has been given by taking as an example a system including a strobe that can be attached to and detached from the camera and a camera, even a camera having a built-in strobe can set the control irradiation angle as described above.

  As described above, the guide numbers are displayed on the display unit 23 of the strobe 2 in the first to sixth embodiments. This value indicates the maximum guide number that can emit light, and depends on the luminance of the subject. The guide number is set to an appropriate value.

It is a block diagram which shows the circuit structure of the flash imaging | photography system concerning each Example of this invention. It is a flowchart which shows the operation | movement with the camera and strobe in Example 1 of this invention. It is a figure which shows the relationship between image quality mode, a lens focal distance, etc. in Example 1 of this invention. It is a flowchart which shows the operation | movement with a strobe in Example 2 of this invention. It is a figure which shows the relationship between image quality mode, a lens focal distance, etc. in Example 2 of this invention. It is a flowchart which shows the operation | movement with the camera and strobe in Example 3 of this invention. It is a flowchart which shows the operation | movement with a strobe in Example 4 of this invention. It is a figure which shows the relationship between image quality mode, a lens focal distance, etc. in Example 4 of this invention. It is a flowchart which shows the operation | movement with the camera and strobe in Example 5 of this invention. It is a figure which shows the relationship between image quality mode, a lens focal distance, etc. in Example 5 of this invention. It is a flowchart which shows the operation | movement with the camera and strobe in Example 6 of this invention. It is a figure which shows the relationship between natural light brightness | luminance, a strobe light contribution rate, a focal distance correction value, etc. in Example 6 of this invention. It is a figure which shows the relationship between natural-light brightness | luminance and a strobe light contribution rate in Example 6 of this invention. It is a figure which shows the irradiation characteristic of the flash light at the time of general flash photography.

Explanation of symbols

1 Camera 2 Lens 3 Strobe (device)
4 Shooting Lens 8 Image Sensor 14 System Control Unit 21 Strobe System Control Unit 24 Light Emitting Unit

Claims (8)

Imaging means for imaging a subject;
Image quality selection means for selecting a recording quality of an image captured by the imaging means;
Setting means for setting the irradiation angle of the strobe light based on the focal length information of the photographing lens and the recording image quality selected by the image quality selection means;
When the focal length information of the photographing lens is the same, the setting means sets the irradiation angle of the strobe light to the wide angle side as the recording image quality selected by the image quality selection means is higher . The strobe photographing system according to claim 1, wherein the recording quality of the captured image is determined based on an image size and a compression rate when recording the captured image . Having photometric means for measuring subject brightness,
3. The strobe photographing system according to claim 1 , wherein the setting unit sets an irradiation angle of the strobe light to a wide-angle side as the subject brightness obtained by the photometry unit decreases. A stroboscopic device that is detachable from a camera having an imaging unit that images a subject and an image quality selection unit that selects a recording quality of an image captured by the imaging unit,
Based on the focal length information of the photographic lens and the recording image quality selected by the image quality selection means, setting means for setting the irradiation angle of the strobe light,
The strobe device characterized in that, when the focal length information of the photographing lens is the same, the setting means sets the irradiation angle of the strobe light to the wide angle side as the recording image quality selected by the image quality selection means is higher . 5. The strobe device according to claim 4 , further comprising a transmission unit that receives information on a focal length of the photographing lens from the camera and information on a recording image quality selected by the image quality selection unit . The transmission means receives information on subject brightness from the camera,
6. The strobe device according to claim 5 , wherein the setting means sets the irradiation angle of the strobe light to a wide angle side as the subject brightness based on the information received by the transmission means is lower . Imaging means for imaging a subject;
Image quality selection means for selecting a recording quality of an image captured by the imaging means;
Setting means for setting the irradiation angle of the strobe light based on the focal length information of the photographing lens and the recording image quality selected by the image quality selection means;
The camera is characterized in that, when the focal length information of the photographing lens is the same, the strobe light irradiation angle is set to the wide-angle side as the recording image quality selected by the image quality selection device is higher . Having photometric means for measuring subject brightness,
The camera according to claim 7, wherein the setting unit sets an irradiation angle of the strobe light to a wide-angle side as the subject brightness obtained by the photometry unit decreases .

Images