PURPOSE: To level photographing frequencies and to automatize most part of operations by controlling a reference sound pressure level at a corresponding stop position in accordance with the number of releasing times at each stop position stored in a storage means.

CONSTITUTION: The reference sound pressure level is classified into eight ranks according to the magnitude of sound pressure. When the counting of second of interval time stored in a memory, that is, the time from the release of the last time but one till the release of the last time is equal to or below one minute, the reference sound pressure level is made higher by one by judging that a release condition easily holds. When the time is within one to three minutes, the sound pressure level is kept as the set level and when the time is equal to or above three minutes, the sound pressure level is made lower by one by judging that the release condition hardly holds. By referring to the photographing frequency(the number of releasing times) at the stop position of a camera, the release is difficult to be performed at the stop position where the photographing frequency is high thereafter. On the contrary, at the stop position where the photographing frequency is low, the release is easy to be performed thereafter.