Imaging apparatus and method of controlling the image depth of field

An imaging apparatus comprising:

• an imaging device;
• a lens which forms an image and collects light on said imaging device;
• a shift control unit configured to shift an object-space focal point of said imaging apparatus by shifting an image-space distance between said imaging device and said lens;
• an exposure time determining unit configured to determine an exposure time based on an image scene;
• and
• a shift pattern determining unit configured to determine a shift pattern of the image-space distance, such that the focal point moves from one end to an other end of a predetermined range of focus during an exposure period of which duration is the exposure time, the image-space distance being shifted by said shift control unit, and the shift pattern being found in a frame period including the exposure period,
• wherein said shift pattern determining unit is configured to determine the shift pattern such that:
• a shift speed of the image-space distance increases from zero during an acceleration period included in the frame period;
• the image-space distance shifts at a constant speed during a constant speed period included in the frame period and following the acceleration period;
• and
• the shift speed of the image-space distance decreases to zero during a deceleration period included in the frame period and following the constant speed period, and
• each of the acceleration period and the deceleration period has a duration equal to or longer than one-tenth of the frame period.