A zoom optical system includes only one optical-element group moved in a magnification
change and at least one deformable mirror having a compensating function for compensating
for a shift of an image surface caused by the magnification change and a focusing
function. According to this configuration of the zoom optical system, it is possible
to attain a zoom optical system and an imaging apparatus using the zoom optical
system that have as small a number of movable lenses as possible, are very small
in size, and work with an extremely low power consumption and low operation noise.
