The Auto Bellows is placed between the OM body and lens to provide the lens extension required in close-up and macrophotographic work. With the double cable release, the diaphragm automatically stops down to the pre-selected aperture at the moment of exposure. The pre-set lever enables you to view the depth of field prior to taking the picture. Since macrophotographs at magnifications greater than 1:1 should be taken with the lens reversed, the Auto Bellows provides a removable lens mounting board. This enables you to reverse the lens without removing the lens from the lens board by extra convenience.