Abstract: In a first exposure condition calculating operation, proper exposure conditions in imaging are calculated by the imaging element including the effective exposure time and ISO sensitivity without preliminary light emission from the strobo part. In a second exposure condition calculating operation, the exposure condition is determined by compensating at least the ISO sensitivity among the exposure conditions calculated in the first exposure condition calculating operation by dimmer or light control operation with preliminary light emission of the strobo part. Exposure of the imaging element is executed as a regular imaging operation under the exposure condition calculated and determined in the second exposure condition calculating operation.

Abstract: A lens barrel apparatus according to the present invention incorporates a cam cylinder serving as a lens barrel having cam grooves for moving frame. Spring portions serving as spring means for making predetermined holding force are formed adjacent to the cam grooves to cause the cam grooves to pinch the cam followers. The cam grooves are continuous grooves or openings formed in the surface adjacent to the cam cylinder. The spring portions are constituted by a plurality of openings formed adjacent to the cam grooves. The lens barrel apparatus exhibiting a simple structure having the small number of elements can be operated by a structure constituted by a cam and a cam follower free from any looseness.