I'm guessing the mirror is being released early, the shadow is way to indistinct to be from the edge of the metal shutter curtain on the Copal Square shutter. Those cameras had a motor drive available, and the extra wear could be the cause of the problem. See:
http://www.mir.com.my/rb/photography...s/fm/part5.htm There is a pdf file of the timing of the mechanisms you can look at.
And a reply from the ebay seller when I inquired about a (partial) refund after he described it as working perfectly:
Awesomeness. More positive karma for me and negative for him.
Hi. I'm very sorry I got camera from estate sale in chicago and the saler tell me the camera working I paid for this camera for $110.00.
I held the mirror up while releasing the shutter at 1/500th and 1/1000th. Same effect. It's definitely the rear shutter curtain which seems to not even open up all the way. So it'll probably end up at KEH.
For everyone that thinks the shadow would be sharp at the edge of the shutter, here is a photo from my Spotmatic shot at 1/1000th which has the same problem (which goes away after you fire the shutter about 5 times.) The Pentax has a horizontal shutter travel.
Originally Posted by luke_h
It would be sharp with electronic flash. I tended to also think it was the mirror. In natural light there's no real reason why it would be sharp, if the shutter is dragging or hanging up, unless it were stopping altogether.
Nice shot of the dog, BTW.
Looking at the pictures you posted I think you have a slow (sticky) first curtain because the exposed part of the picture is on top. If the pictures were taken with flash and using too high shutter speed the exposed part would be on the bottom. I believe there are 2 gears on the bottom of the camera that allows you to increase the spring tension on the shutter curtain. One is for the first curtain and one is for the second curtain. However, excercise the camera a lot might just cure it.
It's not your fault the seller bought & sold a defective camera, if it came through the auction site, I'd INSIST on returning it. It wasn't as described.
Originally Posted by luke_h
For all you know he was aware the camera was defective. Believe it or not there are some unscrupulous folks on the bay.
1) Don't send it to the guy in Kansas!
2)The shutter does have to be removed from the chassis to be adjusted but the good thing is, once adjusted they stay that way for a long time.
If the spring lost tension, it's not age or use that caused the fault you see, it's more likely been dropped or bumped & lost a tooth or two of tension. A little bit goes a long way.
3)It does look like the Nikon and your Pentax share some flaws but the Pentax is the easier to cure. If you refer to Chan Tran's post that's the cure for the Pentax, a simple travel time adjustment.
Heavily sedated for your protection.
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Regarding your Pentax-Eric Hendrickson has a great reputation.
Camera Clinic in Shoreline, WA would also do a good job. For $138, you'd get a full overhaul of your FM. Or, they might sell you a pre-overhauled FM for the same amount of money.
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