I was GIVEN a superb almost Mint OM-2 Spot Program and load more OM gear by a Widow Lady -- read the OM-2 SP 'Eats Batteries' so i did some research and was told on the 'Amateur Photographer Magazine' site Forum Olympus Section that if you set shutter to a RED Mechanical Speed of '60' or 'B' it turns OFF the battery circuit and it works !

