Mark C
Well-known
Have you looked through it from the back, or can you do that on a Contax I? You should be able to see if there if something in the mount interfering by look from the corners of the frame with the camera angled.
I have this adapter:
https://shop.cameraquest.com/nikon-...adapters/amedeo-dedicated-50mm-sc-to-leica-m/
You specify for Contax or Nikon lens. Focus seems to be set for about 2.8, but easily corrected to 1.5 by very slightly unscrewing the rear group (a small fraction of a turn), see my and Dante's comments later in this thread,
http://www.rangefinderforum.com/forums/showthread.php?t=79437
I don't get any vignetting like you are showing. Some falloff at large apertures obviously.
Dralowid
Michael
Of course, my apologies Erik, you would never go over to the dark side...
Erik van Straten
Veteran
Erik van Straten
Veteran
Erik van Straten
Veteran
Yes, you can of course, but you do not see anything remarkable. I think it is a design fault as it happens in two of my Contaxes. I have a Kiev too. I will try the lens on that one soon.
Erik.
Corran
Well-known
This is a scan from such a picture. I always scan the negative.
Erik.
It looks to me like the lens is slightly higher than intended (a bit of front rise, so to speak). Very strange that it happens on two different Contax I bodies, but nevertheless the cut-out corners in the upper left/right (as apposed to just heavy vignetting on the bottom) seem to indicate that.
Erik van Straten
Veteran
Yes, but you mean slightly lower (the top of the picture is at the bottom). Also strange is that my other lenses, Jupiter 8M and Tessar 50/2.8, work perfectly on the cameras. And the Sonnar 50/1.5 works perfect on the Nikon S2 (I did however not check the sharpness, only the vignetting, totally absent).
I think that the curve that controls the rangefinder in the cameras is too big for the lens. This curve is much steeper than the curve on the back of Leica-lenses. That part simply gets too much in the way. I see that now. In the Kiev it is much smaller.
Erik.
Corran
Well-known
No, I do mean too high (the lens). Just like when I use too much front rise on a large format camera, which causes vignetting at the top of the image (bottom of the film). It is strange, though perhaps the other lenses have slightly larger image circles? Or maybe you are right and it's something internal to the cameras, but I'm at a loss as to how.
I've shot my b&n and Contax I(f) and never seen that, but also mine just simply will not shoot properly with the cassette, even with spacers, always slipping down and causing sprocket holes in the image, as I've mentioned in the past. I don't take exacting notes so I'm not 100% sure if any of my images were shot with the 50mm f/1.5 at near infinity.
I've shot my b&n and Contax I(f) and never seen that, but also mine just simply will not shoot properly with the cassette, even with spacers, always slipping down and causing sprocket holes in the image, as I've mentioned in the past. I don't take exacting notes so I'm not 100% sure if any of my images were shot with the 50mm f/1.5 at near infinity.
Erik van Straten
Veteran
The curve that drives the rangefinder is right behind the bayonet-fitting. The Sonnar f/1.5 is bigger than the other lenses. The curve that drives the rangefinder is a very large part. It obscures the lens partly at infinity, towards the bottom of the camera. When you focus the lens, the part moves up (turns) and the lens moves forward, so at close distances there is no problem anymore. The curve works as a too long lens hood on the inside of the camera.
It is a design fault. The makers improved it in the Contax II. To improve it on the already sold cameras was too much trouble.
Erik.
Corran
Well-known
Do you mind posting an image of what you are talking about? I don't see anything like that on my camera.
Gben
Established
Here is one shot of the side of the lens sitting on the body I purchased with it, and another of it head-on:
Erik van Straten
Veteran
You can see it if you remove the back of the camera and open the shutter at "B" or "Z". Then look through the opening of the shutter towards the lens. Then you see on the Contax I the curve that drives the rangefinder. That part is the cause of the trouble.
I can not take any pictures of it now, I'm afraid.
Erik.
I can not take any pictures of it now, I'm afraid.
Erik.
Erik van Straten
Veteran
Thank you, Gben, can you make a picture from the back of the Contax I with the shutter open to show the curve that drives the rangefinder? You must remove the back then.
Erik.
Erik.
Erik van Straten
Veteran
Maybe you have to alter the turning prongs in the camera so they fit better into the cassette. I have a Contax I with the same problem. Always sprocketholes in the pictures.
Erik.
Gben
Established
If you are so interested in this problem you are having with your cameras, then you should start a thread on it instead of hijacking other people's?
I noticed that with a couple of films in one of my IIs. My other one never had this problem. After closely examining various (Contaflex SLR) take up spools I have here, I noticed something. Whilst most removable Zeiss spools will fit a Contax (II/III, at least) later ones have a ridge around the inner diameter of the top (Ie the end closest to the top of the camera when installed). This lowers the film enough that sprocket holes intrude into the image area. I substituted a spool with a completely flat end when I loaded my most recent film and I think it's going to eliminate the issue but obviously, I won't know for certain until I've finished and developed the roll.
Not having used the original Contax I don't know if it will make as much difference with that, however I do recommend inspecting the take up spool you use and substituting the correct type, because, whilst it may not completely eliminate the issue with your camera, I think at the minimum it will probably improve it somewhat.
Cheers,
Brett
Corran
Well-known
Thread drift is a fact of life. Everyone is discussing Contax I cameras, including foibles that very well may affect yours. Lighten up.
Corran
Well-known
Thanks. Still not seeing anything that I can identify. Maybe I'm just being dense.
Highway 61
Revisited
This is all true. I have some Contax take-up spools which were in some Zeiss Ikon reloadable cassettes originally. They are shorter than the take-up spools designed to be used with disposable film cartridges.
Erik van Straten
Veteran
In my camera with the sprocket problem the cause is on the other side of the camera. The teeth of the prong are too big (or the holes of the Kodak cassette are too small) for the ready bought Kodak cassette. I need to file them off. I am not sure that I will do that, however.
Erik.