An imaging device includes a matrix array of photosensor pixels. An
effective area in the array is set to a first region during a first mode
of operation of the imaging device, and is set to a second region during
a second mode of operation of the imaging device. The first and second
regions are different in number of photosensor pixels contained therein.
A holder retains the array. The holder is moved between a first position
at which an optical axis related to light incident to the array coincides
with a center of the first region and a second position at which the
optical axis coincides with a center of the second region. The holder is
fixed at the first position during the first mode of operation of the
imaging device, and is fixed at the second position during the second
mode of operation of the imaging device.