Patent ID: 7477314

Claim:
A method of controlling an exposure control mechanism of an image pickup apparatus, comprising the steps of: determining a luminance level of an image signal entering said image pickup apparatus; controlling movement of a first diaphragm element, a second diaphragm element and an ND filter unit having a plurality of filter elements, based on the determined luminance level; and calculating a total movement amount to be performed in said controlling step, wherein said calculating step comprises: calculating an error amount based on a predetermined target luminance level and the determined luminance level; and calculating the total movement amount based on the error amount and a previous movement amount; setting a control range and movement amount of said first and second diaphragms based on the calculated total movement amount; and setting a control range and movement amount of said ND filter unit based on the calculated total movement amount and the set movement amount of said first and second diaphragms.