Patent ID: 8451372

Claim:
An image shooting apparatus, comprising: an imaging unit operable to read out signals from an image sensor and output image frames in sequence at a predetermined frame rate, the image sensor collecting charges through a photoelectric conversion of incident light; a frame rate changing unit operable to change a frame rate while the imaging unit outputs the image frames in sequence; an aperture adjusting unit operable to adjust a level of aperture that determines an amount of the incident light; an exposure time adjusting unit operable to adjust an exposure time that is a time taken for collecting the charges through the photoelectric conversion of the incident light; a determining unit operable to determine a post-change aperture level so that a post-change amount is substantially equal to a pre-change amount, the post-change amount being an amount of collected charges corresponding to each frame of an image shot at a post-change frame rate, the pre-change amount being an amount of collected charges corresponding to each frame of an image shot at a pre-change frame rate, where the frame rate changing unit changes the frame rate from the pre-change frame rate to the post-change frame rate; and a control unit operable, before the change of the frame rate, to control the aperture adjusting unit to adjust the level of aperture to transit to the post-change aperture level determined by the determining unit, and to control the exposure time adjusting unit to adjust the exposure time in accordance with the level of aperture in transition so that the post-change amount of collected charges is substantially equal to the pre-change amount of collected charges, wherein the adjustment to the level of aperture by the aperture adjusting unit and the adjustment to the exposure time by the exposure time adjusting unit, under control by the control unit, are completed before the change of the frame rate is initiated, the post-change frame rate is higher than the pre-change frame rate, and the image shooting apparatus further comprises: a recording instruction obtaining unit operable to obtain an instruction for recording; a conversion unit operable to convert from an image frame output at the post-change frame rate to an image frame output at the pre-change frame rate; and a storage unit storing the image frames output from the imaging unit, wherein, when the recording instruction obtaining unit obtains the instruction for recording after the frame rate changing unit changes the frame rate, the storage unit stores a predetermined number of image frames before and after the receiving of the recording instruction, and image frames other than the image frames before and after the receiving of the recording instruction are converted conversion unit and results of the conversion are stored in the storage unit.