If you leave it on A, it will set the correct aperture for the shutter speed selected. If you take it off A, it works like any other manual camera (you have to pick both aperture and shutter speed). Assuming it does not have the squeal that a number of these bodies have developed (usually associated with the shutter curtain's lubricant drying out, which means it may be off in the shutter times), the camera is a tank that just keeps going, assuming there is a battery in it. I previously owned one which developed the squeal; $150 to repair seemed excessive, so I figured out it was over-exposing by 2/3 of a stop and compensated by changing the ISO. Found another at a garage sale for $20 and chucked the faulty one.