I couldn't pass up the bargain. Yesterday my wife and I were passing a local antique shop and it was going out of business. They had a cabinet with a bunch of old cameras and accessories. I started browsing through gear...most of which held no interest for me...and came across an old Spiratone 400mm, f6.3 lens in pristine condition. It was marked $35.00. At 50% off, I bought it for $17.50. It was a T-mount and fully manual, including the iris which, once selected needed to be stopped down by moving a ring on the lens body. It also had a tripod mount collar. Well, I have a M4/3 adapter. So last night I put the whole thing together and tried it out. It shows promise. Not super sharp, but I wasn't working under the best conditions and was shooting a half-moon at a very high ISO. I'm anxious to see how it performs in daylight. I'll post something if it turns out to be as good a lens as the price.