29SNIKKOR45mm1 : 2.8PNikon0000000007070.7.0.000000000000000000707000000000000000Frame CounterWhen opening/closingthe camera backSecond blank exposureFirst shot20th shot... The frame counter has indications of S, 1, 2, 4, 6, etc., up to 36 in even numbers. Frames of oddnumbers are indicated by dots between the even numbers.... The counter stops at 36. However, film will be advanced up to the actual end of the film roll.... Even if there is no film in the camera, the frame counter is operative and advances by a singleframe every time you wind the advance lever.... The frame counter is automatically reset to “S” when the camera back is opened.Depth of Field Preview Lever• When you press the depth of field pre-view lever toward the camera body, thelens is stopped down to the specifiedaperture setting, enabling you to checkthe depth of field through the viewfinder.... When checking the depth of field with an Ai-type lens attached to the camera, press the depthof field preview lever fully. Release the lever before you shoot.... When you press the lever, the image in the viewfinder is darkened according to the specifiedlens aperture.