JP2015185925A - Imaging device and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device capable of enhancing the success rate of shooting a still image, and to provide a control method thereof.SOLUTION: An angular velocity sensor 111 detects the deflection of an imaging device, a motion vector detector 141 detects motion of a subject image from a captured image. A camera shake correction control unit 117 performs image blur correction control by drive control of a shift lens group 104. A camera control unit 132 performs shooting control by acquiring the detection data from the angular velocity sensor 111, the detection data from the motion vector detector 141, and the focal distance information from a shooting lens unit 101. When the image position is changed by image blur correction control at the time of shooting, the camera control unit 132 determines whether or not a subject is captured as a still image by means of an imaging element 122, and then determines change of the exposure time and execution of continuous shooting.

Description

  The present invention relates to an imaging apparatus such as a camera having an image blur correction function, and more particularly to an imaging assistance technique for suitably performing panning.

The panning shot by the camera is a method of shooting a subject (moving object) at a shutter speed slower than usual while following the subject. According to this method, an image in which the background flows and the subject is stationary can be obtained. The user can take a photograph full of speed by panning. However, since long-time shooting is performed, it is difficult to match the speed of the subject and the speed of shaking the camera during the exposure period, which is one of the shooting techniques that require skill.
In order to easily realize panning, Patent Document 1 detects the difference between the speed of the subject and the speed of shaking the camera, and corrects the shift amount corresponding to the difference using the camera shake correction function. A method for assisting panning is disclosed. Hereinafter, this method is referred to as panning assist.

JP 2006-317848 A

In the prior art disclosed in Patent Document 1, there is a limit to the angle at which correction is possible by the camera shake correction function. Therefore, when the difference between the speed of the subject and the speed when the camera is shaken is significant, there is a possibility that the panning is not successful. For a user, there are often few shooting opportunities in panning, so it is required to reduce the possibility of shooting failure as much as possible.
An object of the present invention is to provide an imaging apparatus and a control method therefor that make it possible to increase the success rate of still image shooting during panning shooting.

  An apparatus according to a first aspect of the present invention is an imaging device that detects a shake and corrects an image shake by an image shake correction unit, and that captures an image of a subject formed through a photographing optical system. First detection means for detecting shake of the imaging device, second detection means for detecting movement of a subject image from an image captured by the imaging means, exposure time setting means for setting an exposure time, Acquisition means for acquiring focal length information of the photographing optical system, drive control for performing drive control of the image blur correcting means by acquiring the output of the first detection means and the second detection means, and the focal length information And when the image blur correction unit is driven by the drive control unit and the subject is not captured as a still image by the imaging unit, the exposure time is changed by the exposure time setting unit and then the continuous shooting control is performed. Performed, and a photographing control means does not control the changes and continuous shooting the exposure time if it is captured as a still image by the subject is the image pickup means.

  An apparatus according to a second aspect of the present invention is an imaging device that detects a shake and corrects the image shake by an image shake correction unit, and that captures an image of a subject formed through a photographing optical system. First detection means for detecting shake of the imaging device, second detection means for detecting movement of a subject image from an image captured by the imaging means, exposure time setting means for setting an exposure time, Acquisition means for acquiring focal length information of the photographing optical system, drive control for performing drive control of the image blur correcting means by acquiring the output of the first detection means and the second detection means, and the focal length information Means, an operation means used for setting a panning shot, and a shooting control means for controlling the continuous shooting by changing the exposure time by the exposure time setting means when the operation means is set to perform a panning shot. , Be prepared That.

  According to the present invention, the success rate of still image shooting can be increased.

1 is a configuration diagram of an imaging apparatus according to a first embodiment of the present invention. It is a flowchart explaining the process of the camera control part in 1st Embodiment of this invention. It is a flowchart explaining a non-shooting permission determination process. It is a block diagram of a camera-shake correction part. It is a flowchart explaining the panning control in a lens control part. It is a block diagram of panning assist control. It is a figure explaining a panning determination process. It is a flowchart explaining the process of the camera control part in 2nd Embodiment of this invention. It is a block diagram of the imaging device which concerns on 3rd Embodiment of this invention. It is a flowchart explaining 3rd Embodiment of this invention. It is a flowchart explaining 4th Embodiment of this invention. It is a figure which shows the example of a display in 4th Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
[First Embodiment]
FIG. 1 is a diagram illustrating a configuration example of an imaging apparatus according to the first embodiment of the present invention, and illustrates a configuration of a mirrorless camera equipped with a panning assist function. The interchangeable lens 100 in FIG. 1 is an optical device that can be attached to the camera body 120. The interchangeable lens 100 includes a photographing lens unit 101 including a main photographing optical system 102, a zoom lens group 103 that can change a focal length, and a shift lens group 104. The shift lens group 104 is a correction lens that optically corrects an image shake with respect to the optical axis caused by a shake of the imaging apparatus by moving the image in a direction perpendicular to the optical axis direction. The zoom encoder 105 detects the position of the zoom lens group 103 and outputs a detection signal to a lens system control microcomputer 113 (hereinafter referred to as a lens control unit). From the detection signal of the zoom encoder 105, the focal length of the photographic lens unit 101 can be acquired. The position sensor 106 detects the position of the shift lens group 104, and the detection signal is output to the lens control unit 113 via the amplifier 115.

  The angular velocity sensor 111 is a first detection unit that detects a shake of the imaging apparatus. The shake detection signal is amplified by the amplifier 112 and then output to the lens control unit 113. The driver 114 drives the shift lens group 104 in accordance with a control signal from the lens control unit 113. The mount contact portion 116 is a connection portion with the camera body portion 120. The lens control unit 113 includes a camera shake correction control unit 117 that performs camera shake correction control, and a panning control unit 118 that performs control for panning assist. The lens control unit 113 also performs focus lens control, aperture control, and the like, which are omitted for simplification of illustration. At the time of image blur correction, for example, detection and correction processing related to two orthogonal axes such as the horizontal direction and the vertical direction are executed. Since these are the same configuration, only one axis will be described below.

  The camera body 120 includes a shutter 121 and an image sensor 122 such as a CMOS (complementary metal oxide semiconductor) sensor. The output signal of the image sensor 122 is processed by the analog signal processing circuit 123 and then sent to the camera signal processing circuit 124. The camera signal processing circuit 124 includes a motion vector detection unit 141 as second detection means for detecting the motion of the image. A timing generator (TG) 125 sets operation timings of the image sensor 122 and the analog signal processing circuit 123. The operation unit 131 includes a power switch, a release switch, a changeover switch for setting whether to set the panning assist mode, and the like.

  A camera system control microcomputer (hereinafter referred to as a camera control unit) 132 controls the system of the entire camera. The driver 133 drives the shutter driving motor 134 in order to perform the shutter operation. The memory card 171 is a recording medium that records captured image data. The display unit 172 includes a display device such as a liquid crystal panel (LCD) that is used for a monitor of an image to be captured by the camera and displays the captured image. The camera body 120 is provided with a mount contact 161 for the interchangeable lens 100. The lens control unit 113 and the camera control unit 132 perform serial communication at a predetermined timing via the mount contact units 116 and 161. The camera control unit 132 includes a shutter control unit 151 that sets an exposure time, a determination unit 152 that determines success or failure of panning, and a subject angular velocity calculation unit 153 that calculates an angular velocity of the main subject.

  In the imaging apparatus, when the user turns on the power using the operation unit 131, the camera control unit 132 detects the state change. The camera control unit 132 executes power supply and initial setting processing to each circuit of the camera body 120. Power is supplied to the interchangeable lens 100, and the lens control unit 113 executes an initial setting process in the interchangeable lens 100. Communication between the lens control unit 113 and the camera control unit 132 starts at a predetermined timing. In this lens-camera communication, information regarding the camera state, shooting settings, and the like is transmitted and received from the camera body 120 to the interchangeable lens 100 at necessary timings. Further, focal length information, angular velocity information, and the like of the interchangeable lens 100 are transmitted and received from the interchangeable lens 100 to the camera body 120 at necessary timings. In the normal mode in which the panning assist mode is not set, the angular velocity sensor 111 detects camera shake due to camera shake or the like in the interchangeable lens 100. An image blur correction operation is performed when the camera shake correction control unit 117 drives the shift lens group 104 using the detection result.

  The camera shake correction function will be described with reference to FIG. FIG. 4 is a configuration diagram relating to a camera shake correction operation. The same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. Each unit 401 to 408 in FIG. 4 shows a detailed configuration of the camera shake correction control unit 117.

  An A (Analog) / D (Digital) converter 401 converts a shake detection signal from the angular velocity sensor 111 into a digital signal. Data sampling at the time of A / D conversion with respect to the output of the angular velocity sensor 111 (output after the amplifier 112) is performed at, for example, about 1 to 10 kHz. The shake detection signal is processed by a filter calculation unit 402 configured by a high-pass filter (HPF) or the like, and an offset component included in the output of the angular velocity sensor 111 is removed. Further, panning countermeasure processing is performed by changing the cutoff frequency of the filter calculation in accordance with the magnitude of the shake detected by the angular velocity sensor 111. The first integrator 403 converts angular velocity data into angular displacement data in order to generate drive target data for the shift lens group 104. The A / D converter 407 converts the output of the position sensor 106 (output after the amplifier 115) into digital data. The adder 404 adds the outputs of the first integrator 403 as a positive input and the output of the A / D converter 407 as a negative input. That is, the actual drive data of the shift lens group 104 is calculated by subtracting the current shift lens position from the drive target value of the shift lens group 104. The filter calculation unit 405 acquires the output of the adder 404 and performs predetermined filter processing. According to the processing result, a PWM (pulse width modulation) output unit 406 converts the calculated movement amount data into a PWM signal and outputs it to the driver 114 for driving the shift lens. The adder 404, the filter calculation unit 405, and the PWM output unit 406 constitute a drive control unit for the shift lens group 104.

  The panning control unit 408 acquires the output signal of the A / D converter 401 and determines whether the camera is panned from the state indicated by the angular velocity data. When the panning control unit 408 determines panning of the camera, the panning control unit 408 performs cut-off frequency change control of the filter calculation unit 402 and output adjustment of the first integrator 403.

Next, panning control will be described with reference to FIG. FIG. 5 is a flowchart illustrating panning control, and the following processing is executed by the camera shake correction control unit 117 in the lens control unit 113.
In S501, the average value (average value for a predetermined number of sampling times) of angular velocity data captured by the A / D converter 401 is compared with a first threshold value (denoted as a predetermined value α), and the average value is greater than the predetermined value α. It is determined whether it is large. If the average value is less than or equal to the predetermined value α, it is determined that panning has not been performed, and the process proceeds to S507. If the average value is larger than the predetermined value α, the process proceeds to S502.

  S502 is a process for determining whether or not the average value of the angular velocity data is greater than a second threshold value (denoted as a predetermined value β and “β> α”). As a result of the determination, if the average value is less than or equal to the predetermined value β, it is determined that slow panning is being performed, and the process proceeds to S506. On the other hand, when the average value is larger than the predetermined value β, it is determined that fast panning is performed, and the process proceeds to S503. In step S503, the cutoff frequency of the HPF in the filter calculation unit 402 is set to the maximum value, and in step S504, image blur correction control is forcibly set to OFF. This setting is performed in order to eliminate the uncomfortable feeling when the shift lens group 104 is gradually stopped by increasing the cutoff frequency of the HPF and the camera shake correction control is turned off. Also, during fast panning, the amount of movement due to panning is very large relative to the size of camera shake. For this reason, even if camera shake remains by turning off camera shake correction control, there is no sense of incongruity. If an attempt is made to correct panning as a large blur without performing this setting, the image is temporarily stopped at the start of panning. After that, at the moment when the shift lens group 104 reaches the end of the movable range, the image suddenly moves greatly, so that it appears to the user as a very unnatural movement.

  In S505, a process of gradually changing the output of the first integrator 403 from the current data to the data of the center position is executed, and control is performed so as to move the shift lens group 104 to the center position of the movable range. This is because it is desirable that the position of the shift lens group 104 be at the center position of the movable range when the image blur correction operation is restarted next time. If the average value of the angular velocity data is equal to or smaller than the predetermined value β in S502 (when it is determined that slow panning is performed), the process proceeds to S506, and the cutoff frequency of the HPF is set according to the size of the angular velocity data. Is set. This is because the effects of camera shake cannot be ignored when slow panning is performed. The process of S506 is a process necessary for performing the camera shake correction while keeping the image followability at the time of panning not to be unnatural. Then, the process proceeds to S508.

On the other hand, when the average value of the angular velocity data is equal to or smaller than the predetermined value α in S501 (when it is determined that panning is not performed), the process proceeds to S507, and the cutoff frequency of the HPF is set to the normal value. In step S508, the forced OFF setting of the image stabilization (image blur correction) control is canceled.
FIG. 7 illustrates the relationship between the lateral angular velocity data during panning and the predetermined values α and β. The horizontal axis is the time axis, and the vertical axis indicates the change in the sampling value of the angular velocity data 701. In this example, an angular velocity output in the + direction is obtained when panning in the right direction, and an angular velocity output in the-direction is obtained when panning in the left direction. An example is shown in which sudden panning in the right direction and slow panning in the left-right direction are detected. As can be seen from FIG. 7, during the panning, the angular velocity data greatly deviates from the center value. Therefore, when the angular velocity data is integrated to calculate the drive target value of the shift lens group 104, the output of the first integrator 403 becomes a very large value due to a DC (direct current) offset component, and the control becomes impossible. There is a possibility of falling. Therefore, when panning is detected, it is necessary to cut the DC component by changing the HPF cutoff frequency higher. In the case of rapid panning, the output of the first integrator 403 becomes particularly significant, so that control for increasing the cutoff frequency is performed.
By performing panning control as described above, it is possible to monitor an image without a sense of incongruity during panning. In this example, the panning operation is described, but the same applies to the tilting operation.

  When the user sets the panning assist mode using the operation unit 131 in FIG. 1, the camera control unit 132 switches to control for panning assist. Since the setting information of the panning assist mode is transmitted from the camera control unit 132 to the lens control unit 113, the lens control unit 113 shifts to the panning assist mode. In the camera body unit 120 during setting of the panning assist mode, the motion vector detection unit 141 in the camera signal processing circuit 124 detects the motion vector of the subject from the image information and outputs the detected motion vector to the camera control unit 132. The camera control unit 132 receives angular velocity data detected by the angular velocity sensor 111 in the interchangeable lens 100 from the lens control unit 113.

  When the photographer is taking a panning shot, the motion vector of the subject output from the motion vector detection unit 141 includes two types: a vector corresponding to the main subject to be photographed and a vector corresponding to the flowing background. Become. In this case, since the purpose is panning, data with a small amount of motion among the two types of detected motion vectors becomes the motion vector of the main subject. The value of this motion vector corresponds to the amount of movement of the main subject image on the image plane. On the other hand, the angular velocity data received by the camera controller 132 from the lens controller 113 corresponds to the panning speed of the camera. Therefore, by calculating the difference between the received angular velocity data and the angular velocity data calculated from the movement amount of the main subject image on the image plane and the current focal length of the lens, the angular velocity data relating to the movement of the main subject is obtained. It is done. The camera control unit 132 transmits the calculated angular velocity data relating to the movement of the main subject to the lens control unit 113.

  FIG. 6 is a configuration diagram relating to shift lens drive control in the interchangeable lens 100 in the panning assist mode. Each unit 601 to 606 shows a detailed configuration of the panning control unit 118. The difference from FIG. 4 will be mainly described.

  The camera information acquisition unit 601 acquires setting information and shutter release information for the panning assist mode from the communication control unit 610. The angular velocity data output unit 602 acquires (samples) angular velocity data from the A / D converter 401 at a predetermined timing, and transmits the angular velocity data to the camera control unit 132 via the communication control unit 610. The subject angular velocity acquisition unit 603 acquires the angular velocity information of the main subject necessary for the panning assist from the camera information acquired from the communication control unit 610. The adder 604 calculates the difference between the angular velocity data from the A / D converter 401 as a positive input and the angular velocity data of the subject from the subject angular velocity acquisition unit 603 as a negative input. The calculated difference data is output to the second integrator 605. The second integrator 605 performs an integration operation only for a predetermined period, and outputs an integration calculation result to the adder 404. The setting change unit 606 changes the setting of the panning control unit 408 according to the mode information acquired by the camera information acquisition unit 601. A communication control unit 610 in the lens control unit 113 performs bidirectional communication with the camera control unit 132.

  When the user operates the switch of the camera body unit 120 to set the panning assist mode, camera information is read from the communication control unit 610 by the camera information acquisition unit 601 and notified to the setting change unit 606. The setting change unit 606 changes the setting of the panning control unit 408 according to the notified mode information. The setting change performed here is a change for facilitating the transition to a rapid panning state. Specifically, the predetermined values α and β for panning determination described above are changed. Further, the angular velocity data output unit 602 sends the angular velocity data to the communication control unit 610 in order to transmit the detected angular velocity data to the camera control unit 132. Further, the angular velocity information of the movement of the main subject image transmitted from the camera control unit 132 to the lens control unit 113 is read by the subject angular velocity acquisition unit 603. The adder 604 calculates a difference between the angular velocity data detected by the angular velocity sensor 111 and the angular velocity information of the movement of the main subject image, and outputs the difference to the second integrator 605. The second integrator 605 starts the integration operation based on the signal acquired by the camera information acquisition unit 601 indicating that it is during the exposure period, and in the other period, the second integrator 605 is positioned at the center position of the movable range of the shift lens group 104. Output the corresponding value. When control is performed to place the shift lens group 104 at the center position of the movable range in a period other than the exposure period, the shift lens group 104 moves steeply from the current shift lens position to the center position at the end of the exposure period. become. However, immediately after the end of the exposure period, reading from the image sensor 122 corresponds to a period during which the image disappears on the display screen. Therefore, the movement of the image due to the abrupt change of the shift lens position is not a problem. The output of the second integrator 605 becomes a positive input to the adder 404 and is added together with the output of the first integrator 403 (positive input) and the position information (negative input) of the shift lens group 104. As a result, the driving amount of the shift lens group 104 is calculated.

  When the photographer performs a panning operation while setting the panning assist mode, the panning control unit 408 immediately controls the steep panning state in the interchangeable lens 100. That is, as shown in S503 to S505 in FIG. 5, the image blur correction operation is prohibited, and the output of the first integrator 403 is an output corresponding to the center position of the movable range of the shift lens group 104. As a result, the position of the shift lens group 104 is corrected by a drive amount corresponding to the difference between the angular velocity at the time of panning the camera and the angular velocity related to the subject. Therefore, during the exposure period, the difference between the camera panning speed and the subject speed is offset by the movement of the shift lens group 104, so that the panning is successful.

  By the way, if the difference between the panning speed of the camera and the speed of the subject is large, there may be a case where the cancellation by the movement of the shift lens group 104 is not sufficient. The determination unit 152 shown in the camera control unit 132 of FIG. 1 detects whether or not the panning has succeeded by detecting in advance whether or not the difference between the camera panning speed and the subject speed can be canceled by the movement of the shift lens group 104. Determine.

A processing example of shooting control performed by the camera control unit 132 will be described with reference to the flowcharts of FIGS. FIG. 2 is a flowchart showing a shooting sequence in the panning assist mode. FIG. 3 is a flowchart showing the process for determining whether or not the panning is successful.
In S201 of FIG. 2, it is determined whether or not the release switch has been pressed halfway. When the half-press operation is performed and the first switch (denoted as S1) is turned ON, the process proceeds to S202, and when S1 is OFF, the process proceeds to S203. In S202, a process of incrementing the value of the time measurement counter is executed, and the process proceeds to S204. In S203, the time measurement counter is reset, the process returns to S201, and the determination process is repeated until the release switch is pressed halfway.

  S204 is a determination process as to whether or not the angular velocity of movement of the main subject image has already been calculated. If the angular velocity of movement of the main subject image has been calculated, the process proceeds to S205, and if the angular velocity has not been calculated, the process proceeds to S206. In S205, it is determined whether or not the value of the time measurement counter has become a value corresponding to the predetermined time T. That is, when the predetermined time T has elapsed, the process proceeds to S206, and when the predetermined time T has not elapsed, the process proceeds to S207.

  In S206, the angular velocity of movement of the main subject image is calculated. Here, the reason for recalculating the angular velocity of the movement of the main subject image is to consider the case where the velocity of the main subject changes over time. The angular velocity of movement of the main subject image calculated in S206 is transmitted to the lens control unit 113. In S207, success or failure determination of the panning assist operation is performed. This determination process will be described later with reference to FIG.

  In S208, it is determined whether or not the release switch has been fully pressed. If the second switch (denoted as S2) is turned on by the full depression of the release switch, the process proceeds to S209. If S2 is OFF, the process returns to S201. In this case, the process of S201 to S207, that is, the success / failure determination of the panning shot is repeated while the subject speed information is updated at a predetermined cycle.

  In S209, shooting is performed in the current camera setting state. After shooting, in S210, the determination result in S207 is confirmed. If it is determined that the panning is successful, the shooting sequence is terminated. If it is determined in S207 that the panning has not been successful, the process proceeds to S211, where the shutter speed is changed to a faster value, and the process of adjusting the exposure state of the camera according to the change in the shutter speed is executed. In step S212, photographing is performed again. Thus, by increasing the shutter speed during continuous shooting, the possibility of failure of panning shots can be further reduced. Although it is conceivable that the exposure is underexposed by increasing the shutter speed, when the panning is originally performed, the shutter speed is set slower than the normal camera control state. For this reason, in many cases, the aperture is further narrowed and the ISO sensitivity is also low. Therefore, even if the shutter speed is increased during the continuous shooting (continuous shooting) in S212, the possibility of underexposure is very low. In addition, when continuous shooting is performed during panning, the angle of view changes to some extent. However, since there is a high possibility that the photographer can capture the target object, it is possible to reduce the probability of failure for a single shooting opportunity.

  Next, with reference to FIG. 3, the process of S207 in FIG. First, in step S <b> 301, the camera control unit 132 takes in the moving angular velocity of the camera, that is, the angular velocity data detected by the angular velocity sensor 111 in the interchangeable lens 100 acquired through communication with the lens control unit 113. Next, in S302, a difference (denoted as A) between the moving angular velocity of the camera and the above-described angular velocity data of the movement of the main subject image is calculated. In S303, from the difference data A calculated in S302, the shutter speed set by the camera, and the focal length information, the movement amount of the shift lens group 104 necessary for successful panning (hereinafter referred to as the necessary movement amount). Is written as B). In step S <b> 304, the camera control unit 132 captures the maximum movement amount (denoted as C) of the shift lens group 104 acquired from the lens control unit 113 through communication.

In S305, the required movement amount B calculated in S303 is compared with the maximum movement amount C of the shift lens group 104 acquired in S304. As a result of the comparison, if the required movement amount B is equal to or greater than the maximum movement amount C, the process proceeds to S306, and if the required movement amount B is less than the maximum movement amount C, the process proceeds to S307. In S306, it is determined that the panning has failed, and in S307, it is determined that the shift panning has been successful. After S306 or S307, the process proceeds to return processing.
In this embodiment, when the image blur correction unit using the shift lens group is driven and controlled during shooting, and the subject is not captured as a still image, continuous shooting control is executed after the shutter control unit changes the exposure time. Is done. According to the present embodiment, the success rate of the panning shot can be increased by performing the continuous shooting while changing the exposure time according to the result of the success / failure determination of the panning shot.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The present embodiment is different from the first embodiment in the determination conditions in the success / fail determination process of panning. The success / failure determination process of the panning is performed according to the position of the shift lens group during the panning shooting period to determine whether continuous shooting is possible. Note that the configuration of the imaging apparatus according to the present embodiment is the same as that of the first embodiment, and thus detailed description thereof is omitted by using the reference numerals already used. The way of omitting such description is the same in the embodiments described later.

Hereinafter, a second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a flowchart showing an example of shooting control performed by the camera control unit 132 according to the second embodiment, and shows a shooting sequence in the panning assist mode. In FIG. 8, the processing of S201 to S206, S208, and S209 is the same as that in FIG. Hereinafter, S809 to S812 which are different points will be described.
After the photographing process in S209, the camera control unit 132 acquires and confirms the position data of the shift lens group 104 transmitted from the lens control unit 113 in S809. In S810, regarding the confirmed position of the shift lens group 104, the displacement amount of the shift lens group 104 by the panning assist operation is determined with respect to the movable range. When it is determined that the position of the shift lens group 104 is the end position of the movable range, there is a high possibility that the panning has failed due to the shift lens group 104 hitting the correction end (end of the movable range). . In addition, the position sensor of the shift lens group 104 is often made up of a Hall element and a magnet. In this position sensor, there is a possibility that the linearity in detection characteristics is lowered near the end of the movable range of the lens. Therefore, when the shift lens group 104 has moved to the vicinity of the end of the movable range and a decrease in linearity is assumed, there is a possibility that the actual drive position may deviate from the drive target value of the shift lens group 104. It is done. Occurrence of misalignment increases the possibility of failure of panning. Furthermore, when the interchangeable lens 100 is a zoom lens and photographing on the wide side is assumed, if the shift lens group 104 is moved to the vicinity of the end of the movable range, the correction angle becomes large. Therefore, there is a possibility that panning may fail due to the influence of optical distortion such as trapezoidal distortion. Therefore, in this embodiment, when it is determined in S810 that the position of the shift lens group 104 is at or near the end position of the movable range, the process proceeds to S811. After the shutter speed is changed to a fast value in S811 and the camera setting update process is executed, continuous shooting is performed in S812. On the other hand, when it is determined in S810 that the position of the shift lens group 104 is not the end position or the vicinity of the end of the movable range, the processing ends without executing the processing of S811 and S812. Note that the vicinity of the end is a position within the movable range set with respect to the end position of the movable range, and is determined in advance from the maximum angle of image blur correction.

  In the present embodiment, when performing the panning assist using the shift lens group 104, the position of the shift lens group 104 during photographing is confirmed. When the shift lens group 104 hits the end of the movable range or moves to the vicinity of the end, the exposure time is changed and continuous shooting is performed. Therefore, it is possible to reduce the probability of failure of the panning without executing a pre-determination process for the success or failure of the panning before shooting.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. In the present embodiment, a configuration example in which continuous shooting is always performed during setting of the panning assist mode will be described.
FIG. 9 is a configuration diagram of an imaging apparatus according to the third embodiment of the present invention, and shows a configuration example of a single-lens reflex camera equipped with a panning assist function. The camera shake correction function is mounted not in the interchangeable lens but in the camera body. In FIG. 9, differences from FIG. 1 will be mainly described.
The imaging apparatus includes an interchangeable lens 900 and a camera main body 920. The interchangeable lens 900 includes a photographing lens unit 901 and a lens control unit 911. The zoom encoder 105 detects the position of the zoom lens group 103 and outputs a detection signal to the lens control unit 911 to acquire the focal length. The lens control unit 911 performs aperture control and the like.

  The camera body 920 includes an optical finder 973, a main mirror 961, and a pentaprism unit 962. The output of the photometric sensor 922 is processed by the analog signal processing circuit 923 and output to the camera signal processing circuit 124. A part of the light beam collected by the photographic lens unit 901 is reflected by the main mirror 961, guided to the pentaprism unit 962, and forms an image on the photometric sensor 922 and the optical viewfinder 973. The image sensor 934 is arranged so as to be movable in a direction perpendicular to the optical axis direction of the photographing optical system. That is, image blur correction is performed by movement control of the image sensor 934. The driver 932 drives the image sensor 934 in a direction perpendicular to the optical axis direction in order to perform an image blur correction operation according to a control signal from the camera control unit 931. The position sensor 933 detects the position of the image sensor 934 and outputs a detection signal to the camera control unit 931. The angular velocity sensor 941 detects camera shake and outputs a shake detection signal to the camera control unit 931.

  In the camera control unit 931, the camera shake correction control unit 951 controls image blur correction based on the detection signal of the angular velocity sensor 941. The panning control unit 952 performs control in the panning assist mode. In the present embodiment, the camera shake correction control unit 951 and the panning control unit 952 are incorporated in the camera control unit 931, but the internal control is the same as in the first embodiment. The determination unit 953 in the camera control unit 931 determines whether the captured image is in the panning state based on the panning speed information related to the camera body 920 obtained from the detection signal of the angular velocity sensor 941 and the set shutter speed information. Judging. The determination unit 953 determines whether the exposure state of the captured image is appropriate.

In the present embodiment, the image blur correction operation and the panning assist operation are performed by moving the image sensor 934 in a direction perpendicular to the optical axis direction instead of the shift lens group. The motion vector detection for detecting the amount of movement of the main subject is performed using the output of the photometric sensor 922 instead of the output of the image sensor 934.
FIG. 10 is a flowchart for explaining a processing example of shooting control performed by the camera control unit 931, and shows a shooting sequence in the panning assist mode. In FIG. 10, the processes of S201 to S206 and S208 are the same as those of FIG. 2, so detailed description thereof will be omitted, and differences S1009 to S1013 will be described.
After shooting in S208, in S1009, the determination unit 953 calculates a shutter speed (threshold is denoted as S) that is allowable in panning from the panning speed based on the output data of the angular velocity sensor 941. Thereafter, in S1010, the shutter speed is changed to a faster value, and an exposure state changing process is performed accordingly. In next step S1011, the determination unit 953 compares the shutter speed S calculated in step S1009 with the currently set shutter speed. As a result of the comparison, if the current shutter speed is faster than the shutter speed S calculated in S1009, the effect of the panning shot does not appear, and the shooting is terminated.

If the current shutter speed is slower than the shutter speed S calculated in S1009 in S1011, the process proceeds to S1012 and the determination unit 953 determines whether or not the set exposure is under. If the currently set exposure is underexposed, the photograph can be expected to succeed, so the shooting is stopped. If it is determined in S1012 that the currently set exposure is not under, the process proceeds to S1013 and continuous shooting is performed. Then, returning to S1010, the shutter speed is changed again. That is, every time continuous shooting is performed, a process for changing the setting to shorten the exposure time is performed, and the determination processes in S1011 and S1012 are repeated. If the shutter speed is slower than the threshold value S in S1011, or if it is determined that the exposure is underexposed in S1012, continuous shooting is stopped. As described above, since the continuous shooting is performed while the shutter speed is changed and the effect of the panning shot is present and the exposure is in an appropriate exposure state, the possibility of taking a success shot of the panning shot is increased.
In the present embodiment, when the panning assist mode is set, the success probability of panning can be increased by performing continuous shooting while changing the shutter speed as compared with the case of single shooting.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. This embodiment relates to a notification process when continuous shooting is performed in the panning assist mode. FIG. 11 is a flowchart regarding an operation sequence in the panning assist mode in the present embodiment. The following processing is realized by the CPU (central processing unit) of the camera control unit 132 executing a control program. In FIG. 11, the processing of S201 to S212 is the same as that of FIG. 2, so that the description thereof is omitted and S1108, S1109, and S1115 that are different points are described.

If the success / failure determination result of the panning assist is successful in S1108 after S207 in FIG. 11, the process proceeds to S208. If it is determined that the success is not successful, the process proceeds to S1109. In S1109, warning display control to the display unit 172 is set to ON, and the process proceeds to S208. In the warning display control, notification processing such as a message to the photographer is executed.
When it is determined in S201 that the first switch S1 of the release switch is in the OFF state, the process proceeds to S1115 after the time measurement counter is reset in S203. In S1115, the warning display control to the display unit 172 is set to OFF, and the process returns to S201.

  In the present embodiment, when the panning assist mode is set, the camera setting is forced to be continuously shot in order to reduce the probability of shooting failure. Therefore, the photographer may not be able to determine whether the current shooting operation is a continuous shooting operation. As a result, if the camera is moved carelessly even though continuous shooting is being performed, panning in continuous shooting will not succeed. Therefore, when there is a possibility that the panning may fail, a message to that effect is displayed on the display unit 172, or notification is given by sound from a speaker or the like. Accordingly, the photographer is notified that continuous shooting is to be performed and is alerted, so that it is possible to avoid inadvertently moving the camera. FIG. 12 illustrates a message displayed on the screen of the display unit 172. In this example, a message for urging the camera to continue shooting and to keep the camera from moving carelessly is displayed.

In this embodiment, the success rate of the panning shot can be increased by notifying the photographer that continuous shooting is performed by warning display control in the panning mode.
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 Interchangeable lens 104 Shift lens group 111 Angular velocity sensor 113 Lens control part 120 Camera main body part 132 Camera control part 141 Motion vector detection part 152 Pan shot determination part

Claims (19)

An imaging apparatus that detects shake and corrects image shake by image shake correction means,
An image pickup means for picking up a subject image formed through the photographing optical system;
First detection means for detecting shake of the imaging device;
Second detection means for detecting movement of a subject image from an image captured by the imaging means;
Exposure time setting means for setting the exposure time;
Obtaining means for obtaining information of a focal length of the photographing optical system;
Drive control means for acquiring the output of the first detection means and the second detection means, and information on the focal length and performing drive control of the image blur correction means;
When the image blur correction unit is driven by the drive control unit and the subject is not captured as a still image by the imaging unit, the exposure time is changed by the exposure time setting unit, and then continuous shooting is controlled. An imaging apparatus comprising: an imaging control unit that does not change the exposure time and control continuous imaging when the imaging unit captures a still image.   The shooting control means determines success or failure of the panning before shooting, determines that the panning is not successful when the subject is not captured as a still image by the imaging means, and changes the exposure time by the exposure time setting means. The imaging apparatus according to claim 1, wherein continuous imaging control is performed.   The photographing control means calculates the amount of movement of the image blur correction means from the difference between the output of the first detection means and the output of the second detection means, the set exposure time, and the focal length information. The success or failure of the panning is determined by comparing the amount of movement with a threshold value.   The imaging apparatus according to claim 3, wherein the imaging control unit determines that the panning is successful when the movement amount of the image blur correction unit is smaller than the threshold value.   The imaging apparatus according to claim 3, wherein the threshold value is a value indicating an end position of a movable range of the image blur correction unit.   The photographing control means determines success or failure of the panning after the photographing, and when it is determined that the panning is not successful, the exposure time is changed by the exposure time setting means and the continuous photographing is controlled. The imaging device according to claim 1.   The shooting control unit acquires the position information of the image shake correction unit during the shooting period, and compares the position information with the end position of the movable range of the image shake correction unit, thereby determining success or failure of the panning. The imaging apparatus according to claim 6.   8. The imaging according to claim 7, wherein the photographing control unit determines that the panning is successful when the position of the image blur correcting unit is not the end position or the vicinity of the end of the movable range of the image blur correcting unit. apparatus. An imaging apparatus that detects shake and corrects image shake by image shake correction means,
An image pickup means for picking up a subject image formed through the photographing optical system;
First detection means for detecting shake of the imaging device;
Second detection means for detecting movement of a subject image from an image captured by the imaging means;
Exposure time setting means for setting the exposure time;
Obtaining means for obtaining information of a focal length of the photographing optical system;
Drive control means for acquiring the output of the first detection means and the second detection means, and information on the focal length and performing drive control of the image blur correction means;
Operation means used for setting the panning;
An imaging apparatus comprising: an imaging control unit configured to control continuous imaging by changing an exposure time by the exposure time setting unit when the operation unit is set to perform panning.   The photographing control unit obtains the output of the first detection unit and the exposure time set by the exposure time setting unit, determines the result of the panning, and performs control to perform or stop the continuous photographing. The imaging apparatus according to claim 9.   The imaging according to claim 10, wherein the imaging control unit determines a result of panning by comparing an exposure time with a threshold value, and stops the continuous imaging when the exposure time is shorter than the threshold value. apparatus.   The imaging apparatus according to claim 10 or 11, wherein the imaging control unit stops the continuous imaging when the exposure is under-exposed.   12. The imaging apparatus according to claim 1, wherein the exposure time setting unit sets the exposure time to be shorter every time the continuous shooting is performed.   The imaging apparatus according to claim 1, wherein the imaging control unit performs a process of notifying the continuous imaging by display or sound. The photographing optical system includes a correction lens,
The image pickup apparatus according to claim 1, wherein the image blur correction unit includes a drive unit that moves the correction lens in a direction different from an optical axis direction of the photographing optical system.   The image pickup apparatus according to claim 1, wherein the image shake correction unit includes a drive unit that drives the image pickup unit in a direction different from an optical axis direction of the photographing optical system.   The imaging apparatus according to any one of claims 1 to 16, wherein the first detection unit detects an angular velocity of shake, and the second detection unit detects a motion vector of the captured image. A control method executed by an imaging apparatus that detects shake and corrects image shake by an image shake correction unit,
A first detecting unit detecting a shake of the imaging device, and a second detecting unit detecting a movement of a subject image from an image captured by the imaging unit;
A drive control unit performing drive control of the image blur correction unit based on the outputs of the first detection unit and the second detection unit and information on the focal length of the photographing optical system acquired by the acquisition unit;
The photographing control means has a photographing control step for controlling exposure time change and continuous photographing by the exposure time setting means,
In the shooting control step, when the image blur correction unit is driven by the drive control unit and the subject is not captured as a still image by the imaging unit, the shooting control unit changes the exposure time by the exposure time setting unit. A control method for an image pickup apparatus, wherein continuous shooting control is performed, and when the subject is picked up as a still image by the image pickup means, the exposure time change and the continuous shooting control are not performed. A control method executed by an imaging apparatus that detects shake and corrects image shake by an image shake correction unit,
A first detecting unit detecting a shake of the imaging device, and a second detecting unit detecting a movement of a subject image from an image captured by the imaging unit;
A drive control unit performing drive control of the image blur correction unit based on the outputs of the first detection unit and the second detection unit and information on the focal length of the photographing optical system acquired by the acquisition unit;
The imaging control unit has a step of controlling the continuous shooting by changing the exposure time by the exposure time setting unit when it is set to perform the panning by the operation unit used for setting the panning shooting. Control method of the device.

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