JP2013105024A - Stroboscope and wireless stroboscope control system - Google Patents

Abstract

There is provided a strobe control system capable of preventing a failed photograph due to poor synchronization even when mounted on a camera that does not support wireless strobe control.
A camera that can output an X signal to a strobe, a master strobe device that can be attached to the camera, and a slave strobe device, and wireless communication from the master strobe device with the slave strobe device. In a strobe control system for exchanging information and control, the master strobe device has means for determining whether the camera is compatible with wireless multi-flash control, means for acquiring a shutter speed, and means for acquiring an X tuning value. The master strobe device sends a flash command to the slave strobe device in synchronism with the X signal from the camera to perform strobe shooting, and the shutter speed is synchronized. A means for displaying a warning if there is a time near the second is provided.
[Selection] Figure 6

Description

  The present invention relates to an imaging device, a strobe device, a strobe control camera system, a synchronized photographing method using the same, and a program that constitute a wireless communication system.

  In a multi-lamp control system, Patent Document 1 proposes a system in which a camera performs wireless communication with a slave strobe, thereby centrally controlling the operation of the slave strobe on the camera side and performing flash photography.

  However, since the wireless transmission / reception operation has a delay depending on the communication speed and a delay due to retransmission when communication fails, it is necessary to take light emission synchronization of the shutter timing in consideration of this.

  For this reason, for example, in Patent Document 2, in the strobe control in which the camera and the strobe perform wireless communication, the slave strobe transmits a response trigger packet in response to reception of the light emission command from the camera. After that, it is disclosed that when the reception response packet is received, the camera performs the shutter front curtain operation after the elapse of a first predetermined period and performs the front curtain synchronization flash photography after the second predetermined time.

JP 2000-89306 A JP 2010-185961 A

  However, a strobe for a camera is generally provided to users as a compatible accessory, and can be attached to various cameras.

  Therefore, it is necessary to consider that a strobe equipped with the above-described light emission synchronization technology is mounted on a camera that has been released in the past, that is, a camera that does not support light emission command transmission for wireless communication.

  Accordingly, an object of the present invention is to provide a strobe control system that can prevent a failure photograph due to poor synchronization even when the camera is mounted on a camera that does not support wireless strobe control.

  In order to achieve the above object, the present invention has a camera capable of outputting an X signal (flash synchronization signal) to a strobe, a master strobe device that can be attached to the camera, and a slave strobe device having a light emitting means. In a strobe control system that exchanges information and control with the slave strobe device through wireless communication from the master strobe device, the master strobe device determines whether the camera is compatible with wireless multi-flash control. The master strobe device further includes a means for acquiring a shutter speed from a camera mounted thereon, and a means for acquiring an X tuning value (tunable shutter speed) of the camera, and is not compatible with the determination means. If determined, the master strobe device synchronizes with the X signal from the camera. In this case, the apparatus further comprises a notification means for transmitting a flash command to the slave strobe device by wireless communication, performing strobe shooting, and displaying a warning if the shutter speed is near the synchronization time.

  According to the present invention, it is possible to provide a strobe control system that can prevent a failed photograph due to poor synchronization even when the camera is mounted on a camera that does not support wireless strobe control.

It is a block diagram which shows the camera system for demonstrating the Example of this invention. It is a schematic diagram which shows the camera system for demonstrating the 1st Example of this invention. It is a flowchart for demonstrating the Example of this invention. It is a flowchart for demonstrating the Example of this invention. It is a flowchart for demonstrating the Example of this invention. It is a flowchart for demonstrating the Example of this invention. It is a figure which shows an example of the screen display in the Example of this invention. It is a flowchart for demonstrating the Example of this invention. It is a timing chart which shows strobe synchronous imaging | photography for demonstrating the 1st Example of this invention.

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

  FIG. 1 is a block diagram showing a configuration of a camera system (comprising a digital camera, a lens, and a strobe device) according to Embodiment 1 of the present invention.

  Reference numeral 100 denotes a camera body, 200 denotes a lens, and 300 denotes a strobe device (flash device).

  First, the configuration inside the camera body 100 will be described.

  Reference numeral 101 denotes a microcomputer CCPU (hereinafter referred to as camera microcomputer) that controls each part of the camera 100. The camera microcomputer 101 controls the camera system and also performs various condition determinations.

  Reference numeral 102 denotes an image sensor such as a CCD or CMOS including an infrared cut filter, a low-pass filter, and the like, and an image of a subject is formed at the time of photographing by a lens group 202 described later.

  Reference numeral 103 denotes a shutter including a control circuit that shields the image sensor 102 during non-shooting and opens during shooting to guide the light beam to the image sensor 102. The shutter control circuit controls the shutter in accordance with the shutter front curtain drive signal and the shutter rear curtain drive signal 118 from the camera microcomputer 101. Here, the shutter is a known focal plane shutter, and controls the two shutter drive magnets constituting the focal plane shutter to run the shutter front curtain and the rear curtain, and performs the exposure operation.

  Further, a known shutter wing position is detected in the shutter, and a photo interrupter for detecting timing such as completion of shutter travel is built in, and is detected by a signal 119 connected to the camera microcomputer 101.

  The operation of the shutter 103 will be described in detail with reference to the flowchart of FIG. 4 and the timing chart of FIG.

  A main mirror (half mirror) 104 reflects a part of light incident from the lens group 202 when not photographing, and forms an image on a focusing plate 105.

  Reference numeral 105 denotes a focus plate that visually confirms the focus in an optical viewfinder (not shown).

  Reference numeral 106 denotes a photometric circuit. A photometric sensor in the circuit divides the photographing range of the subject into a plurality of areas and performs photometry in each area.

  Reference numeral 107 denotes a focus detection circuit, in which the distance measuring sensor in the circuit has a plurality of points as distance measuring points, and the distance measuring points are included at positions corresponding to the divided portions of the photometric sensor.

  The photometric sensor in the photometric circuit 106 expects a subject image formed on the focus plate 105 via an 11 4 pentaprism described later.

  Reference numeral 108 denotes a gain switching circuit for switching the gain of signal amplification of the image sensor 102. The gain switching is switched by the camera microcomputer 101 according to shooting conditions, level setting based on a charging voltage condition described later, input by the photographer, and the like. I do.

  Reference numeral 109 denotes an A / D converter that converts an amplified analog signal from the image sensor 102 into a digital signal. Reference numeral 110 denotes an amplified signal input from the image sensor 102 and the conversion timing of the A / D converter 109 synchronized with each other. The timing generator (TG).

  A digital signal processing circuit 111 performs image processing on image data converted into a digital signal by the A / D converter 109 according to parameters.

  A memory for storing processed images is omitted.

  Reference numeral 120 denotes a signal line for an interface between the camera 100, the lens 200, and the strobe device 300, and a communication terminal is provided in the accessory shoe. For example, the camera microcomputer 101 is used as a host to exchange data and transmit commands to each other.

  Thus, a light emission start signal to the strobe device 300 and a communication clock terminal with a strobe microcomputer 310 to be described later are provided, and communication between the camera microcomputer 101 and the strobe microcomputer 310 is enabled.

  Similarly, reference numeral 130 denotes a lens mount that is an interface with a lens microcomputer 201, which will be described later, and has a terminal for transmitting data from the lens microcomputer 201 to the camera microcomputer 101, enabling communication between the camera microcomputer 101 and the lens microcomputer 201. Yes.

  112 is used to input arbitrary filter information settings in various input units, and to input camera settings from the outside using a preliminary light emission button for performing preliminary light emission, a switch or button for daytime sync mode, a dial, and the like. Things are possible.

  A display unit 113 includes a liquid crystal device and a light emitting element that display various set modes and other shooting information.

  A pentaprism 114 guides the subject image on the focusing plate 105 to a photometric sensor in the photometric circuit 106 and an optical viewfinder (not shown).

  Reference numeral 115 denotes a sub-mirror that guides a light beam incident from the lens group 202 and transmitted through the main mirror 104 to the distance measuring sensor of the focus detection circuit 107.

  Next, the configuration and operation within the lens 200 will be described.

  Reference numeral 201 denotes a microcomputer LPU (hereinafter, a lens microcomputer) that controls the operation of each part of the lens 200. The lens microcomputer 201 performs lens control and various condition determinations.

  A lens group 202 includes a plurality of lenses.

  A lens driving unit 203 moves an optical system for focusing the lens group 202. The driving amount of the lens group 202 is determined in the camera microcomputer 101 based on the output of the focus detection circuit 107 in the camera 100. Calculated and calculated.

  An encoder 204 detects a position when the lens group 202 is driven.

  The calculated driving amount is communicated from the camera microcomputer 101 to the lens microcomputer 201, and the lens microcomputer 201 operates the lens driving unit 203 by the driving amount according to the driving information of the encoder 204, and the lens group 202 is moved to the in-focus position. .

  Reference numeral 205 denotes a stop, 206 denotes a stop control circuit, and the stop 205 is controlled by the lens microcomputer 201 via the stop control circuit 206.

  The focal length of the lens group 202 may be a single focal point, or the focal length may be variable like a zoom lens.

  Next, the configuration of the strobe device 300 will be described.

  Reference numeral 310 denotes a microcomputer FPU (hereinafter referred to as a strobe microcomputer) that controls the operation of each part of the strobe device 300. The strobe microcomputer 310 controls the strobe device 300 and determines various conditions.

  Reference numeral 301 denotes a battery as a power source (VBAT) of the strobe. It is connected to a booster circuit 302 and a strobe microcomputer 310 which will be described later.

  Reference numeral 302 denotes a booster circuit that boosts the voltage of the battery 301 to several hundred volts, and stores energy for light emission in the main capacitor 303. It is connected to a terminal of the flash microcomputer 310 and controls charging.

  A main capacitor 303 is a high-voltage capacitor for strobe light emission, which is charged to 330 V in the embodiment and discharged during light emission.

  A voltage detection circuit 313 is connected to both ends of the main capacitor 303 and is a main capacitor voltage detection means.

  The voltage charged in the main capacitor 303 is divided by the voltage detection circuit 313 by the resistors 304 and 305, and the divided voltage is input to the A / D conversion terminal via the terminal of the strobe microcomputer 310.

  This information is communicated from the flash microcomputer 310 to the camera microcomputer 101 via accessory shoe communication.

  Reference numeral 306 denotes a trigger circuit. A trigger signal pulse is output from the flash microcomputer 310 during light emission.

  Reference numeral 307 denotes a discharge tube that emits light by receiving and exciting the energy charged in the main capacitor 303 by receiving a pulse voltage of several KV applied from the trigger circuit 306, and irradiating the subject with the light.

  A light emission control circuit 308 controls the start of light emission of the discharge tube 307 together with the trigger circuit 306 and further controls the stop of light emission.

  Reference numeral 323 denotes a photodiode as a sensor that receives the light emission amount of the discharge tube 307, and receives light from the discharge tube 307 directly or through a glass fiber.

  Reference numeral 309 denotes an integration circuit for integrating the light reception current of the photodiode 323, and an input is connected to a terminal in the flash microcomputer 310 as an integration start signal.

  The output of the integration circuit 309 is input to the A / D converter terminal via the inverting input terminal of the comparator 312 and the e terminal of the strobe microcomputer 310.

  The non-inverting input of the comparator 312 is connected to the D / A converter output terminal via a terminal in the flash microcomputer 310, and the output of the comparator 312 is connected to the input terminal of the AND gate 311.

  The other input of the AND gate 311 is connected to the light emission control terminal via the terminal of the strobe microcomputer 310, and the output of the AND gate 311 is input to the light emission control circuit 308.

  Reference numeral 315 denotes a reflector umbrella, and 316 denotes an optical system that is configured by a panel or the like and determines an irradiation angle of the strobe device 300.

  Reference numeral 320 denotes various input units (input interfaces), and an output is connected to a terminal of the flash microcomputer 310. For example, a switch is installed on the side surface of the strobe device 300 and the strobe information can be manually input.

  Reference numeral 321 denotes a display unit for displaying each state of the strobe device 300, which displays the input from the terminal of the strobe microcomputer 310.

  A constant voltage circuit 322 makes the voltage of the battery 301 constant.

  Reference numeral 323 integrates the received light current by an integration circuit 309 of a photodiode.

  A wireless communication circuit 324 and a wireless antenna 325 transmit and receive data using radio waves to and from camera accessories such as an external strobe and a remote controller. A wireless communication packet generated by the flash microcomputer 310 is exchanged with a flash unit 1000 described later via a wireless communication circuit 324 and a wireless antenna 325.

  FIG. 2 is a schematic diagram of a strobe control camera system according to an embodiment to which the present invention is applied. The strobe control camera system according to the present embodiment is a wireless strobe system including a digital single-lens reflex camera and a strobe (flash device).

  Reference numeral 100 denotes the camera described above, which is connected to the external strobe 300 via an accessory shoe. The strobe 300 operates here as a master strobe. The external strobe 300 incorporates a wireless communication circuit and a wireless antenna.

  Reference numeral 1000 denotes an external strobe, which, like the external strobe 300, has a built-in wireless communication circuit and a wireless antenna. The strobe 1000 is a slave strobe and operates by communication instructed by the master strobe. The strobe 300 and the strobe 1000 perform wireless communication by a method such as IEEE802.15.4, which is a known wireless communication standard.

  Reference numeral 400 denotes a subject, 600 denotes a screen, and 500 denotes a tripod for fixing the camera 100, which is assumed to be used for flash photography in a photo studio.

  In the present embodiment, the strobe 300 becomes a master device and the strobe 1000 becomes a slave device, and strobe synchronized shooting is performed in which the shutter of the camera 100 and the light emission of the strobe 300 and the strobe 1000 are synchronized.

  Next, the camera 100 and the strobe 300 are connected as shown in FIG. 2 according to the flowcharts of FIGS. 3, 4, 5, 6, and 7, the display screen of FIG. 8, and the timing chart showing the strobe synchronized shooting of FIG. The sequence of flash synchronization shooting when the flash 300 and the flash 1000 are 1: 1 will be described.

  First, the strobe 300 and the strobe 1000 are registered in advance as communication partners by known wireless pairing.

  The specific operation of the camera microcomputer 101 will be described with reference to the flowchart of FIG.

  When a power switch (not shown) is turned on and the camera microcomputer 101 of the camera 100 becomes operable, the camera microcomputer 101 starts a predetermined operation from step (hereinafter abbreviated as S) 1 in FIG.

  First, in S1, the memory and port of the camera microcomputer 101 itself are initialized.

  In addition, the state of the switch input from the input unit 112 and preset input information are read, and various shooting modes such as how to determine the shutter speed and how to determine the aperture are set.

  When the power of the camera 100 is turned on, the power of the strobe 300 is turned on, and the wireless strobe light emission mode is set, the strobe microcomputer 310 controls the wireless communication circuit 324 via the camera 100 and changes the radio frequency. Scan the channel. Then, the flash 1000 that is the communication partner is searched.

  When the power is turned on, the strobe 1000 controls the wireless communication circuit 324 in the same manner as the strobe 300, sets a channel to be used, and is set in a state where it can respond to a search from the strobe 300.

  When the strobe 300 finds the strobe 1000 by searching, the strobe 300 starts issuing a regular beacon packet (beacon signal) as a network coordinator to start up the network. The strobe 300 also plays a role of a network device, and can link at any time as a communication partner of the strobe 300 so that communication is possible at any time.

After the system including the camera 100, the strobe 300, and the strobe 1000 is activated in this way, the camera 100 is in a state waiting for a release operation from the user (waiting for SW1 to be turned on). It is determined whether or not SW1, which is in the pressed state, is ON. If it is OFF, this step is repeated, and if it is ON, the process proceeds to S3.

  In S <b> 3, the camera microcomputer 101 communicates with the lens microcomputer 201 in the photographing lens 200 via the communication line 130. Then, the focal length information of the photographing lens 200 (hereinafter referred to as the focal length information of the lens), optical information necessary for distance measurement and photometry are acquired.

  In S4, it is checked whether or not the flash device 300 is attached to the camera 100. If the strobe device 300 is attached to the camera 100, the process proceeds to S5, and if not, the process proceeds to S6.

  In S <b> 5, the camera microcomputer 101 communicates with the flash microcomputer 310 via the communication line 120, and outputs the lens focal length information acquired in S <b> 3 to the flash microcomputer 310.

  Accordingly, the flash microcomputer 310 drives the motor drive circuit 313 based on the received focal length information, detects the position by the encoder 314, and controls the irradiation angle of the flash.

  In S5, the camera microcomputer 101 communicates with the strobe microcomputer 310 via the communication line 120, and issues an instruction to output strobe information stored in the memory of the strobe microcomputer 310 itself. Strobe information is output to the microcomputer 101.

  The strobe information data includes current light emission mode information, main capacitor charging information, and the like.

  Next, in S6, it is determined whether the camera is in a mode for performing an autofocus detection operation (AF mode) or not (MF mode) among the photographing modes set in S1.

  The camera microcomputer 101 transmits camera ID information for identifying the type of camera to the flash microcomputer 310.

  If it is AF mode in S6, it will progress to S7, and if it is MF mode, it will progress to S9 immediately. In S7, the focus detection circuit 107 is driven to perform a focus detection operation by a known phase difference detection method. In S7, the point to be matched from the plurality of distance measuring points (ranging point) is determined according to the points input and set by the input unit 112 or the shooting mode of the camera, or near point priority is set. It is determined by a well-known automatic selection algorithm based on the basic concept.

  In S8, the distance measuring point determined in S7 is stored in a RAM (random access memory) (not shown) in the camera microcomputer 101.

  In step S8, the camera microcomputer 101 calculates a lens driving amount based on information from the focus detection circuit 107.

  The camera microcomputer 101 communicates with the lens microcomputer 201 in the photographing lens 200 via the communication line 130. Based on the calculation result, the lens microcomputer 201 controls the lens driving circuit 203 to drive the lens group 202 to the in-focus position, and proceeds to S9.

  In S9, as an example, the subject brightness value is divided into 12 areas on the screen here, and the subject brightness value is obtained from the photometry circuit 106.

  In S <b> 10, the gain switching circuit 108 performs the gain setting process input from the input unit 112. For example, ISO sensitivity setting.

  In S10, the camera microcomputer 101 communicates with the strobe microcomputer 310 via the communication line 120, and outputs the gain setting information acquired in S10 to the strobe microcomputer 310.

  In S11, exposure values (EVs) are determined from subject luminance values EVb of a plurality of areas by a known algorithm.

  In S12, it is checked whether or not the flash microcomputer 310 outputs a charge completion signal. If the flash microcomputer 310 has output a charging completion signal, the process proceeds to S13, and if not, the process proceeds to S14.

  Note that the determination result of whether or not the flash microcomputer 310 in S12 outputs a charge completion signal is stored for use in a later step.

  In S13, a shutter speed (Tv) and an aperture value (Av) suitable for performing flash photography are determined based on the photometric output obtained in S9.

  In S14, a shutter speed (Tv) and an aperture value (Av) suitable for performing natural light photography are determined based on the photometric output obtained in S9. When the process of S13 or S14 is executed, the process proceeds to S15 in any case.

In step S <b> 15, the camera microcomputer 101 communicates with the flash microcomputer 310 via the communication line 120, and outputs information related to other flashes to the flash microcomputer 310.
Subsequently, in S16, it is determined whether or not SW2, which is a shooting start switch (not shown), is ON. If it is OFF, the operations from S1 to S16 are repeated. If it is ON, the sequence of FIG. The operation after the release will be described with reference to the flowchart of FIG.

  In S <b> 17, the camera microcomputer 101 communicates with the flash microcomputer 310 via the communication line 120 and outputs camera information to the flash microcomputer 310.

  In S18, a photometric operation 1 of stationary light is performed.

  In S19, in order to perform pre-flash communication with the flash 300, the camera microcomputer 101 communicates with the flash microcomputer 310 via the communication line 120 in order to perform pre-flash communication, and outputs camera information to the flash microcomputer 310.

  The pre-flash operation of the strobe 300 will be described later with reference to the flowchart of FIG.

  In S20, photometric operation 2 is performed in the strobe pre-flash state of the strobe 300.

  From the photometric information obtained in this way, the shutter speed, aperture value, flash amount of the strobe 300 and strobe 1000 are calculated.

  In S21, the main mirror 104 is raised and moved away from the photographing optical path.

  In S22, light quantity setting communication is performed. The photometric information obtained in S20 is communicated from the camera microcomputer 101 to the flash microcomputer 310 via the communication line 120, and the camera information is output to the flash microcomputer 310.

  The wireless light amount setting communication of the strobe 300 will be described later with reference to the flowchart of FIG.

  In S23, a light emission command is transmitted. The camera microcomputer 101 communicates with the flash microcomputer 310 via the communication line 120 and outputs camera information to the flash microcomputer 310.

  In S24, shutter and aperture operations are performed. In addition, the slave strobe 1000 is ready for light emission and enters a state of waiting for light emission trigger communication. The camera 100 performs mirror up and aperture control under the control of the camera microcomputer 101, starts the front curtain travel of the shutter 103, and controls the image sensor 102 to start accumulation.

  In S25, the main light emission operation is performed. When the shutter 103 is close to the fully open state, the camera 100 outputs an X signal that is a light emission synchronization signal to the strobe 300.

  In the case of single-flash photography with the strobe 300 instead of multi-flash control, the strobe 300 performs the main flash processing in synchronization with the X signal, thereby performing the flash processing in synchronization with the previous shutter timing of the camera 100. Can do.

  On the other hand, in the case of multi-lamp control by wireless communication described in this embodiment, the master flash 300 to the slave flash 1000 perform light emission synchronization by wireless packet communication, and an X signal is input to the master flash 300. After that, there is a delay corresponding to the communication time of the light emission command packet before the slave strobe 1000 starts the light emission processing. For this reason, in a camera that supports multi-flash control by wireless, X-light output is advanced by the communication time between strobes to synchronize the light emission timing of the slave strobe 1000 and the previous shutter timing of the camera 100. Is possible.

  When a series of exposure operations is completed in this way, in S26, the main mirror 104 that has been retracted from the photographing optical path is lowered and is obliquely installed in the photographing optical path again.

  In S27, the A / D converter 109 converts the signal obtained by amplifying the pixel data of the image sensor 102 with the gain set in the gain switching circuit 108 as a digital signal. The converted pixel data is subjected to predetermined signal processing such as white balance by the signal processing circuit 111 in S29. At this time, the white balance is set in consideration of the filter correction information in S24.

  Then, the image data processed in S28 is stored in a memory (not shown), and one image capturing routine is completed.

  Subsequently, a specific operation (strobe control operation) in the strobe microcomputer 310 in the strobe device 300 will be described with reference to the flowchart of FIG.

  When a power switch (not shown) is turned on and the strobe microcomputer 310 becomes operable, the strobe microcomputer 310 starts a predetermined operation from S101.

  First, in S101, the memory and port of the flash microcomputer 310 itself are initialized.

  Further, the state of the switch input from the input unit 320 and preset input information are read, and the flash photographing mode, the light emission amount, and the like are set.

  When the camera microcomputer 101 communicates with the flash microcomputer 310 via the communication line 120, the flash information is output to the flash microcomputer 310.

  This information is stored in a RAM (random access memory) (not shown) in the flash microcomputer 310.

  In S102, the booster circuit 302 is started to prepare for light emission.

  In S103, the lens focal length information obtained from the camera microcomputer 101 via the communication line 130, the shutter speed and aperture value determined by the camera through exposure control, and the flash information such as the light emission mode information are checked. Also, camera ID information for identifying the type of camera is acquired.

  In S104, the strobe information stored in its own memory is displayed on the display unit 321. Here, it is determined whether the camera 100 is compatible with the wireless multi-light control, and the display content is switched based on the result. Details will be described later with reference to FIG.

  In step S <b> 105, the strobe microcomputer 310 communicates with the camera microcomputer 101 via the communication line 120, and strobe information is output to the camera microcomputer 101.

  In S106, it is determined whether or not the voltage boosted by the booster circuit 302 has reached a voltage level necessary for the light emission of the discharge tube 307 (whether charging is completed), and has reached a voltage level necessary for the light emission of the discharge tube 307. If it is determined that there is, the process proceeds to S108.

  If it is determined in S106 that the voltage boosted by the booster circuit 302 has not reached the voltage level necessary for light emission of the discharge tube 307, the process proceeds to step S107.

  In S107, a charging incomplete signal is output to notify the camera microcomputer 101 via the communication line 120 that the strobe is not ready to emit light. The charge signal is sent to the booster circuit 302, and then the process returns to S102 to repeat the above steps.

  In S108, a charging completion signal is output to notify the camera microcomputer 101 via the communication line 120 that the strobe is ready to emit light.

  In step S109, camera information is received. It is checked whether a pre-flash start signal is output from the camera microcomputer 101.

  If the pre-flash start signal is received, pre-flash communication is performed in S110 (corresponding to S19 in FIG. 4 of the operation flowchart of the camera 100).

  The strobe microcomputer 310 controls the wireless communication circuit 324 and transmits it to the slave strobe 1000 via the antenna 325.

  Here, the display operation in S104 of FIG. 5 will be described in detail using the flowchart of FIG.

  In S150, it is determined whether the camera 300 to which the master flash 300 is attached is compatible with the wireless flash. This determination is made based on the camera ID acquired from the camera 100 in advance. The ROM area in the flash microcomputer 310 stores an ID table for identifying cameras that do not support wireless flash. Further, in this ID table, the synchronization time of the camera used in the processing described later is stored in association with the ID. The flash microcomputer 310 searches this ID table, and if there is no camera ID that matches the camera ID acquired from the camera 100 in S103 of FIG. 4, it is determined that the camera is compatible with the wireless flash, and the process proceeds to S151.

  In S151, the normal display shown in FIG. 7B is performed on the display unit 321 of the master strobe 300.

  On the other hand, if it is determined in S150 that there is a match with the camera ID as a result of searching the ID table, that is, if it is determined that the camera does not support the wireless strobe, the process proceeds to S152.

  In S152, the camera 100 determines the synchronization time. The upper limit of shutter speed at which the camera can synchronize with the flash (limit on the high-speed shutter side) depends on the shutter curtain speed of the camera. In the case of a camera with a fast shutter curtain speed, the shutter full-open time tends to be long even at the same shutter speed as for a slow camera, and as a result, the flash can be synchronized on the high-speed shutter side. In the master strobe 300, since the correspondence relationship indicating which camera is in which synchronization time is included in the above-described ID table, the camera synchronization time of the camera is referred to by referring to the camera ID table searched in S150. Can be requested.

  In step S153, the flash microcomputer 310 compares the shutter speed acquired from the camera microcomputer 101 with the synchronization time of the attached camera. As a result, if it is determined that the acquired shutter speed is close to the synchronization time of the camera, the process proceeds to S154. If it is determined that the speed is sufficiently slower than the synchronization time, the process proceeds to S151 and normal display processing is performed as described above. Here, as an example of a method for determining whether or not it is near the tuning time, the time required for the light emission command communication between the master strobe and the slave strobe is stored in the ROM in the strobe microcomputer 310, and the tuning obtained from the ID table is stored. It is only necessary to calculate the tuning ability value of the wireless multi-lamp control in the form of adding the communication delay time in seconds, and to determine that it is near the tuning time when the shutter speed is higher than the tuning ability value. Alternatively, the shutter speed acquired from the camera 100 may be compared with the second on the lower speed side as a reference with respect to the synchronized second acquired from the ID table.

  In S154, a warning as shown in FIG. 7B is displayed. This notifies the user that there is a possibility that the slave strobe may not synchronize at the shutter speed according to the current camera setting, and prompts the user to reset the shutter speed to the low speed second side.

  Next, the wireless communication operation will be described in detail using the timing chart of FIG.

  FIG. 8 is a diagram showing the flowchart of FIG. 5 in the form of a timing chart. Before the SW1 is turned on, the master strobe 300 issues beacon packets at 100 millisecond intervals.

  The strobe 1000 controls the wireless communication circuit 324 to receive the beacon packet at all times by operating the wireless communication circuit 324 at intervals of 100 milliseconds.

  The time required for receiving the beacon packet is several milliseconds, and in the idle state where communication is not particularly necessary, the wireless communication circuit 324 on the flash side needs to operate between the end of the reception operation and the next reception operation. Therefore, it is possible to save power.

  When SW1 of camera 100 is turned on, strobe 300 transmits a packet to notify strobe 1000 that SW1 is turned on at the timing immediately after the beacon packet (SW1 of master strobe transmission data). . At the same time, the control is changed so as to issue beacon packets that have been at intervals of 100 milliseconds until then at finer intervals of about 10 milliseconds. In this way, by changing the beacon packet issue interval before and after the release operation, the response response of the strobe 1000 when SW2 is turned on next time is improved. As the beacon packet interval is shortened, the timing of the receiving operation on the strobe 1000 side is also shortened in accordance with the beacon interval. As a result, instead of improving the response, the operation frequency of the wireless communication circuit 324 increases and the power consumption increases.

  When SW2 of camera 100 is turned on, strobe 300 transmits a packet to notify strobe 1000 that SW2 is turned on at the timing immediately after the beacon packet (SW2 of master strobe transmission data). .

  The flash unit 1000 checks its own charge state, and if it can emit light, notifies the camera 100 to that effect (strobe transmission data completion information / Ack). At the same time, the strobe 1000 is always set to a state in which wireless packets can be received.

  After this state is reached, steps S109 to S118 in FIG. 5 are sequentially executed.

  That is, the camera 100 and the flash unit 300 enter a light control operation (camera operation light control 1, light control 2, exposure calculation), and perform pre-flash communication and light amount setting communication.

  Each time the strobe 1000 receives a packet from the strobe 300, the strobe 1000 ensures the communication reliability by transmitting an Ack packet.

  If the Ack packet is not sent from the flash unit 1000 even after a predetermined time has elapsed with respect to the transmitted packet, the flash unit 300 performs retransmission processing to transmit the same packet again, assuming that a communication error has occurred.

  The strobe 1000 is ready to receive a light emitting command packet, which is a command packet for a synchronous operation, after the light amount setting communication is performed in step S113 described later. That is, the standby state is set in which the main light emission is always possible and synchronized shooting is possible.

  In S110 of FIG. 5, pre-flash communication is performed wirelessly (see master strobe communication data).

  The strobe microcomputer 310 controls the wireless communication circuit 324 and transmits to the slave strobe 1000 via the antenna 325. If it is normal, the strobe 1000 in FIG. 9 transmits an Ack packet (refer to slave strobe communication data).

  In S111, the photometric operation 2 is performed together with the pre-flash operation of the strobe 300 and the strobe 1000 (corresponding to S20 in FIG. 4 of the operation flowchart of the camera 100).

  The pre-flash and main flash operations of the strobe 300 and the strobe 1000 are shown in the flowchart of FIG.

  In S201 of FIG. 8, it is checked whether or not the light emission start signal is output from the camera microcomputer 101. If the light emission start signal is not output, the routine returns from the routine, while the light emission start signal is output. If so, the process proceeds to step S202.

  In step S202, a trigger signal is given from the light emission control terminal of the flash microcomputer 310 to the light emission control circuit 308 via the AND gate 311 to start flash emission.

  In step S203, the camera microcomputer 101 reaches the flash microcomputer 310 via the communication line 120 to reach the light emission amount corresponding to the light amount determined by the light emission amount calculation value, or the light from the discharge tube 307 is photoed directly or via glass fiber or the like. Light is received by the diode 323.

  The integration circuit 309 integrates the light receiving current of the photodiode 323, and the output is input to the inverting input terminal of the comparator 312 and the A / D converter terminal of the strobe microcomputer 310.

  The non-inverting input of the comparator 312 is connected to a D / A converter output terminal in the flash microcomputer 310, and a D / A converter value corresponding to the light amount corresponding to the light amount determined by the light amount calculation value is set.

  For example, the pre-emission amount may be set to a small light amount such as 1/32 of the full emission amount, and the main emission amount may be set to a relative value of the pre-emission amount.

  If it has not reached this level in S203, the light emission is continued.

  In S204, a light emission stop signal is output from the AND gate 311 and the light emission control circuit 308 stops the light emission. Thereafter, the process returns to step S202, and the above steps are repeated.

  In S112 of FIG. 5, camera information is received. It is checked whether a light quantity setting signal is output from the camera microcomputer 101.

  If the light amount has been set from the pre-emission photometric calculation result, the light amount setting communication is performed in S113 (corresponding to S22 in FIG. 4 of the operation flowchart of the camera 100).

  In S113 of FIG. 5, light amount setting communication is performed. The strobe microcomputer 310 controls the wireless communication circuit 324 and transmits to the slave strobe 1000 by the antenna 325 (refer to master strobe communication data).

  If it is normal, the strobe 1000 in FIG. 9 transmits an Ack packet (refer to slave strobe communication data).

  In S114 of FIG. 5, camera information is received. It is checked whether or not a strobe light emission start signal is output from the camera microcomputer 101.

  Thereafter, the front curtain travel is started by the operation of the front curtain travel signal Mg of the camera 100 (S24 in FIG. 4), and the master strobe Xout signal is turned on at the timing of completion of the front curtain travel, that is, S115 in FIG. 9 master strobe Xout signal high level to low level).

  Thereby, the master strobe transmits a light emission command in S116 of FIG. The strobe microcomputer 310 controls the wireless communication circuit 324 and transmits it to the slave strobe 1000 via the antenna 325.

  Here, since a predetermined communication time is required for the transmission of the light emission command, the light emission timings of the master strobe and the slave strobe are shifted as shown by the main light emission waveform in FIG. Then, in the vicinity of the original synchronization time, the slave strobe light is emitted by the shutter rear curtain, and there is a possibility that the light amount is insufficient, that is, the synchronization is poor.

  If the camera equipped with a master strobe is a camera that supports wireless strobe shooting, the main flash timing is aligned by making a request for the slave strobe command to the master strobe in consideration of this deviation time. Can do.

  In contrast, in the case of the camera described in this embodiment, that is, a camera that does not support wireless flash communication, the master flash 300 determines the synchronization time of the camera 100 and the control shutter speed, resulting in poor synchronization. A warning can be displayed to the user when there is a possibility.

  In this embodiment, it is assumed that the first curtain sync shooting is synchronized with the shutter front curtain running completion timing and the flash firing. However, the shutter first curtain running start and the flash firing start are synchronized with high-speed sync photography. However, the same effect can be obtained by applying the present invention.

  The operation of the main light emission is shown in the flowchart of FIG.

  Note that the camera 100 controls the image sensor 102 to the accumulation state when the shutter 103 starts the front curtain travel. When the rear curtain running of the shutter 103 is completed, the image sensor 102 is controlled from the accumulation state to the reading state, and reading of the image data is started.

  The light emission termination process is performed in S118 of the flowchart of FIG.

  A packet for notifying the end of the sequence is transmitted to the strobe 1000 (end of camera transmission data sequence).

  When the strobe 1000 receives the light-emission command packet and is able to emit light normally, it communicates to that effect to the strobe 300 (normal emission / Ack of strobe transmission data).

  The camera 100 determines that the currently captured image is a captured image when the strobe light is emitted normally, and stores the image attached as a shooting condition information to a file again. On the other hand, if the flash photography is not performed normally, the fact is attached and recorded in the image file (corresponding to S26 and S27 in FIG. 4 of the operation flowchart of the camera 100).

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 100 Camera 101 Camera microcomputer 102 Image pick-up element 103 Shutter 116 Wireless communication circuit 117 Wireless antenna 300 Strobe 310 Strobe microcomputer 324 Wireless communication circuit 325 Wireless antenna 1000 Strobe

Claims (2)

A camera (100) capable of outputting an X signal (flash sync signal) to the strobe,
A master strobe device (300) attachable to the camera;
A slave strobe device (1000) having a light emitting means,
In a strobe control system for exchanging information and control with the slave strobe device by wireless communication from the master strobe device,
The master strobe device includes determination means (310, S150) for determining whether the camera is compatible with wireless multi-flash strobe control.
Further, the master strobe device includes means (310, S103) for acquiring the shutter speed from the attached camera, and means (310, S152) for acquiring the X tuning value (tunable shutter speed) of the camera.
If it is determined by the determination means that the master strobe device is not compatible, the master strobe device transmits a flash command to the slave strobe device by wireless communication in synchronization with the X signal from the camera, performs strobe shooting, and the shutter. A strobe control system comprising a notifying means (321) for displaying a warning if the speed is in the vicinity of the synchronization time. 2. The strobe control system according to claim 1, wherein the shutter speed is in the vicinity of the synchronization time when the shutter speed is higher than the shutter speed when the shutter speed is one step lower than the X synchronization value of the camera.