Patent ID: 8204370

Claim:
An image pickup apparatus comprising: an in-focus operation section configured to drive a focus lens to move over a predetermined driving range to detect evaluation values, each of the evaluation values representing a contrast strength of an image signal generated by an image pickup operation of a subject from a plurality of predetermined focal positions, the in-focus operation section finding an in-focus position of said focus lens based on the evaluation values; and a detector configured to acquire first evaluation values obtained for each of said predetermined focal positions during a first period of driving said focus lens over said predetermined driving range, and a second evaluation value obtained for at least one of said predetermined focal positions during a second period between the end of said first period and a process carried out by said in-focus operation section to find said in-focus position of said focus lens on the basis of said first evaluation values, and a change measurement section configured to measure an evaluation difference as a difference between said second evaluation value and a first evaluation value corresponding to the at least one of said predetermined focal positions of said second evaluation value, and determine a velocity of the subject based on the evaluation difference, wherein said in-focus operation section determines a next driving range of said focus lens on the basis of said in-focus position found from said first evaluation values and using the velocity of the subjected determined based on the evaluation difference.