Is this due to the shutter being too fast?

[wiltw]

I found the culprit! On the shutter blades there was a point of dirt, sticky dirt. That single spot was slowing down the upper curtain in such a way that on every speed above 1/125 there was not enough time for the shutter to open completely. I didn't see that, because you must wind the shutter to see the upper curtain come down. I cleaned it with benzene and then again with a cotton bud moistened with just a tad of water and now everything is back to normal. It puzzles me where that spot came from. The seals are fresh and still new, the mirror bumper as well.
It is not an expensive camera to die for, but I hate owing things that partially work.

Congrats, and now you have a better understanding of how the Copal Square shutter works, too! Probably better than a camera tech who would simply have swapped out the entire Copal shutter module without attempting to fix issues within the shutter mechanism.

 

[reddesert]

Shutter curtains - two - are used in horizontal travel shutters. Two cloth type curtains, hence the name.

Vertical travel shutters tend to be made out of multiple blades. With two sets of them.

I am curious though - is there a metal bladed horizontal shutter? The Nikon SP used titanium cloth, but it was still cloth, and still just two pieces.
And also, are there vertical travel shutter curtains? In 35mm cameras? I'd guess in medium format there is as the configuration is more symmetrical with the SLR type cameras.
Many medium format cameras have leaf shutters in the lenses.

I think you're speaking of multi-blade vs a curtain as a monolithic piece. By these terms, the Nikon SP, F, F2 use titanium horizontal travel curtains (but not cloth - cloth to me suggests woven fabric). Many later Canon rangefinders like the P and 7 use steel horizontal curtains. I don't know of a vertical monolithic curtain shutter in 35mm, but almost everything has existed at some point. In medium format, there are lots of focal plane curtain shutters, mostly cloth, occasionally steel; examples are the first series of Mamiya 645 SLRs, Bronica S/EC, early focal plane shutter Hasselblads, the Kiev 88. I think most of the "cuboid" bodies use vertical travel curtain shutters and the "big 35mm" bodies like the Pentax 6x7 or Pentacon 6/Kiev 60 use horizontal, but don't hold me to that. The Mamiya 645 changed its design between the older and newer series. And the Speed Graphic uses a well-known vertical cloth curtain shutter.

To the OP, nice work on finding and fixing the problem.

 

[zanxion72]

I think you're speaking of multi-blade vs a curtain as a monolithic piece. By these terms, the Nikon SP, F, F2 use titanium horizontal travel curtains (but not cloth - cloth to me suggests woven fabric). Many later Canon rangefinders like the P and 7 use steel horizontal curtains. I don't know of a vertical monolithic curtain shutter in 35mm, but almost everything has existed at some point. In medium format, there are lots of focal plane curtain shutters, mostly cloth, occasionally steel; examples are the first series of Mamiya 645 SLRs, Bronica S/EC, early focal plane shutter Hasselblads, the Kiev 88. I think most of the "cuboid" bodies use vertical travel curtain shutters and the "big 35mm" bodies like the Pentax 6x7 or Pentacon 6/Kiev 60 use horizontal, but don't hold me to that. The Mamiya 645 changed its design between the older and newer series. And the Speed Graphic uses a well-known vertical cloth curtain shutter.

To the OP, nice work on finding and fixing the problem.

I always mix terms terribly referring to this as curtains.

Funny, that spot was on the mirror side of the shutter and on one of the blades of the upper set. Spotted it out of pure luck after forgetting the camera with the film advanced and raising the mirror by hand to see what could be wrong with it.

 

[zanxion72]

Congrats, and now you have a better understanding of how the Copal Square shutter works, too! Probably better than a camera tech who would simply have swapped out the entire Copal shutter module without attempting to fix issues within the shutter mechanism.

Quite lucky this time. I am not always that lucky and above all I have some kind of Midas touch. I touch gold and turn it to...

 

[drkhalsa]

The Nikon F2 and F3 for sure. I am not sure about the Nikon F. Also the Hasselblad 2000FC has metal shutter too. Which got damaged easily if you're not careful.
My mistake there is no metal bladed shutter that I know off. The bladed shutter is needed for vertical because there is no room for the full curtain but vertical has advantage of shorter distance.

My Nikon F has a horizontal titanium foil shutter.

 

[Chan Tran]

My Nikon F has a horizontal titanium foil shutter.[/QUOTA
and so the F2 and F3 but they don't have blades. Just 2 curtain.

 

[Sirius Glass]

I think you're speaking of multi-blade vs a curtain as a monolithic piece. By these terms, the Nikon SP, F, F2 use titanium horizontal travel curtains (but not cloth - cloth to me suggests woven fabric). Many later Canon rangefinders like the P and 7 use steel horizontal curtains. I don't know of a vertical monolithic curtain shutter in 35mm, but almost everything has existed at some point. In medium format, there are lots of focal plane curtain shutters, mostly cloth, occasionally steel; examples are the first series of Mamiya 645 SLRs, Bronica S/EC, early focal plane shutter Hasselblads, the Kiev 88. I think most of the "cuboid" bodies use vertical travel curtain shutters and the "big 35mm" bodies like the Pentax 6x7 or Pentacon 6/Kiev 60 use horizontal, but don't hold me to that. The Mamiya 645 changed its design between the older and newer series. And the Speed Graphic uses a well-known vertical cloth curtain shutter.

To the OP, nice work on finding and fixing the problem.

So I like certain cuboid camera bodies. Good to know.