The C330 body I got earlier this year was from a portrait / wedding photographer who has gone digital. He was explaining the system to me and how he had used it for many years with great success. He ran into a problem with sharpness on one of the lenses (not sure which one now), and had sent it back to the factory for a check-up. The problem was as reported earlier in this thread. It seems the shims which came with the lens were not correctly installed. The same lens was returned and was "tack sharp" when he next used it, said this was a common problem with the lenses. The glass was excellent, but the shims would normally be out of adjustment due to an improper c.l.a. or tinkering by someone who didn't understand the lens.
This seems to me to be simply a manufacturing issue from years ago. With today's technology and tolerances, the use of shims would be an unacceptable,costly and unnecessary manufacturing procedure. In the past, it was just a necessary part of the "system" for production. tim
Thanks, that was a great response! After a thorough clean and swap the lens appears to be significantly sharper.
There were some marks on the taking lens which would not budge, the viewing lens was totaly clear though.... i swapped the two over (there were no shims - had certainly been done before!) and performance has definately improved.
It seemed to be diffusing very slightly before, which i think would have been caused by the marks on the lens - i have an enlarger lens which gives similar results.
I do find focussing a bit more difficult - but overall this is a camera im much more comfortable with than the 645. Comparing similar prints of the same grade from the 645 and c330, i think there is a contrast difference - certainly a different general look - i'll try ajusting development a little.
I love the close focussing ability!
In response to Carl Neilson's well documented steps for replacing the C330f's viewing screen assembly's foam, I re-foamed mine. Something clearly needed to be done since sharp focusing below f5.6 wasn't possible, however it didn't solve the discrepancy between the viewing focus and the image on a focus screen I constructed for the film plane. Before I detail my problems, I'll add some advice for others changing their viewing screen assembly foam.
I was able to predict before changing the foam that it wouldn't have made a difference by dabbing some slow drying ink onto the 3 posts in the C330f's body then putting the screen assembly back onto the camera, removing it and seeing 3 ink dots transferred to the underside of the screen. This was despite my foam being in poor condition.
For others reading this thread, the two problems causing my discrepancy were as follows:
- The top of the lens plate/board was able to rock back and forth by about 1mm because the stiff retaining wire didn't press on it when latched as it should. I solved that problem by inserting a small piece of sheet metal (LxWxH about 2mm x 3mm x 1mm) to take up the slack.
- I had previously swapped the front of the viewing and taking lens with each other. This was because I had a small amount of fungus on the taking lens. After considering this might have been the problem I noticed that both lens bodies had different thickness shims between them and the lens plate, also the filter thread of the viewing lens was about 0.5mm further forward than that on the taking lens. After I swapped them back again the focus was identical (to within limits of repeatability).
The amount the focus was out was a distance of 0.6mm linear travel of the focusing rails and about 2.2mm circumferential rotation of the focus knob.
Can you help me solve my C330f focus problem ?
Arrgh. I just checked my focus again this morning after changing nothing and it is off again. I thought I had this problem licked The only things I haven't yet tried (and I think I need the service manual to do them) are:
- Adjusting the mirror
- Swapping lens shims
- Adjusting the 3 factory trimmed vertical posts in the body that press against the underside of the viewing screen.
The discrepancy distance is about 0.6mm horizontal movement of the focus rail. Read my prior post to see what I have tried.
Can anybody give me any other suggestions to try ?
I would consider sending it to a repair outfit that has the equipment to properly inspect the focusing. If someone left shims out of the lens mount, this would be a solution.
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I too have a black 80mm lens that is super sharp. But in the past I had a 55mm lens that was terribly weak. I replaced it with another 55mm that is reasonable good. Not all lenses are created equal.
There is one shim in each lens. The taking lens' shim is very thin and silver, matching that lens' thread colour. The viewing lens' shim is thicker and is black, matching that lens' thread colour. See attached pics.
I'm pretty confident I have the ability to detect the misalignment. I have spooled tracing paper between the two take up reels, and use a thin sheet of perspex/Plexiglas (in place of the pressure plate) to hold the tracing paper flat.
I think you may have a body or lens plate that is bent or deformed. I cannot think of any other reason why the stiff retaining wire wouldn't press on it where it should.
Otherwise, I wonder if the focus problem could be related to the artifacts outside the image area that you referred to in your earlier thread: http://www.apug.org/forums/forum37/9...rames-why.html?
“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”
Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2
I thought so too Matt, but when I hold a steel ruler along it in every direction it is dead flat !! I discovered another poster somewhere whose retaining wire didn't press against the top of the lens plate, but they didn't say their plate was bent. As for the body being bent, that is nigh impossible (but I'll still double check that tonight) since it appears to be cast as a very solid block of metal.
Originally Posted by MattKing
The cause behind the out of frame artifacts isn't the lens but high intensity light bouncing inside the body, refer to the diagram I attached in my last post (#13) here.
In Mamiya TLR’s, shims are also used to align viewfinder screens... as a general suggestion, do not disassemble the viewfinder chamber, even if it is dirty. There is little to gain and a lot of risk to misalign the screen.
Originally Posted by noseoil