charles_caron

Thanks for the info. I found a site (http://olympus.dementia.org/) with lots of useful information. (I don't know why google didn't find that site.)

As it turns out, according to the spec sheet, my zoom lense is not supposed to require refocusing when the focal length is changed. So I definetly have a problem.

I took a good look at the focus screen and it looks like the matte side is down -- not up as it is supposed to be. That same site also had a copy of the repair manual giving detailed instructions on replacing the focus screen. I'll check with a repair company to see if it's reasonably priced before attempting it myself.

Thanks again!

I just pulled my old OM-10 out of the closet the other day. I

stopped using it about 8 years ago because I was having problems

with focussing. (After having had non-warranty work done to clean

the focus screen and replace the light seals.)

I suspect something is wrong with the focus screen but I don't know

how to tell. I have difficulty focussing with my 50mm and 18mm

lenses (looks good through viewfinder but results are frequently

blurry). And with my 75-150mm zoom lense I notice that after

focussing on the subject, if I zoom, it goes out of focus. (I don't

remember this behavior before the work done 8 years ago.)

Could someone suggest a method for me to determine if the focus

screen is improperly positioned, in backwards, etc?