light meter readings

I have an Olympus OM-1. The readings err in the direction of overexposure -- extremely so. With ASA 200, for example, in sunlight, I must set the lens to 1.4 and the shutter to 1 second for the camera to indicate a proper exposure. I have replaced the battery and cleaned the contact, to no avail. Does anyone know what is causing these faulty readings and, equally important, what I can do in response? Thank you for your attention.

Are you sure you have the right battery? I don't know much about Olympus, but I think the older OM's used a mercury battery that's not available anymore. Some of the currently available replacements aren't an exact replacement and can give you false readings because of it.

The other option is that the meter needs to be recalibrated. Find a good local camera shop that does in-house repairs (if any exist in your area - or try KEH) and they can check it out for you. Could actually be a combination of both - I don't think either problem should give you readings that are that far off. In mid-day sun (now that it's summer) you should be at ISO200, 1/250 and f16 (sunny 16 rule).

How long have you had the camera? Has it always done this?

[QUOTE=another view]Are you sure you have the right battery? I don't know much about Olympus, but I think the older OM's used a mercury battery that's not available anymore. Some of the currently available replacements aren't an exact replacement and can give you false readings because of it.

The other option is that the meter needs to be recalibrated. Find a good local camera shop that does in-house repairs (if any exist in your area - or try KEH) and they can check it out for you. Could actually be a combination of both - I don't think either problem should give you readings that are that far off. In mid-day sun (now that it's summer) you should be at ISO200, 1/250 and f16 (sunny 16 rule).

How long have you had the camera? Has it always done this?[/QUOTE

Thank you very much for your assistance. Your remark about the battery has led me to
believe that I have the wrong battery. I have not yet had time to acquire a proper replacement.
On the Internet I have found vintagebatteries.com and photobattery.com, which offer the Weincell substitute for the PX625 mercury, no longer available. First I'll check a local camera shop. Thank you again.

The Wein cells are expensive and don't last long, but seem to work well. B&H has a good deal on them - compared to other places at least.