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Wideopeniris
Tinkerer
Username: Wideopeniris
Post Number: 7
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 08, 2012 - 02:26 am: | 
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I have a Kiev 4 (Contax III copy) which has a major focus error. When focused on infinity it actually focuses at about 8 feet!!
I have three lenses which all show the same effect so it must be the body (or else I am outstanding unlucky!)
I looked up some web resources on how to adjust the flange focal plane of the camera but these are all about adding shims to raise the lens bed. For my problem though the lens needs to be further into the body by a large amount. The flange distance measures about 35.6mm or more so its along way out.
Its a Kiev-4 with meter (flaky). It has the leather covering. Kiev written in script cyrillic and also in latin.
I cant find any way of adjusting the lens further in to the body. Anyone got any ideas or seen this problem before?
Many thanks for any guidance...
Kevin. |
Glenn
Tinkerer
Username: Glenn
Post Number: 1051
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 09, 2012 - 06:08 pm: |
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If my references are correct, the flange to film distance for Contax RF copies is 34.85mm. You therefore need to remove 0.75mm from the rear of the mount flange or the equivalent in shims. No experience of the Kiev 4, but have found plenty of FED and Zorki LTM flanges that were too thick for the body they were mounted on. Some were obviously machining errors, but others may have been Zorki flanges fitted to FED bodies or vise versa. I usually machine enough off the rear of the flange rear face to allow shims to be used to get the correct distance spot on. |
Wideopeniris
Tinkerer
Username: Wideopeniris
Post Number: 8
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 10, 2012 - 02:46 am: |
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I guess this is not so easy on the Kiev. The mount has two sets of lugs - one outside and one inside the mount.
So would you recommend machining that much off the bayonet lugs? Seems like quite a lot, although my Jupiter 9 lens is a pig to mount at the moment, I guess that could be related.
If the problem is a machining error, then I guess the camera never took a good shot in 60 years ! It already wasted a roll of my silver..
The stuff I saw said that Kievs were machined to 35mm although the contax standard is as you say 34.85. I guess if I go to the trouble of machining I ought to correct all my lenses to the contax numbers too and then I'll be able to use the real Zeiss lenses too??
thanks,
Kevin. |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 1245
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 10, 2012 - 04:40 am: |
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You're right, the lens flange of the kiev is more complex than the fed or zorki - it has the focus helical and rangefinder coupling gear in it. 3/4 of a mm is a huge amount, I've never heard of that kind of error in a kiev; there must be something assembled wrong. It is possible that the lens mount was reinstalled with shims that were not there originally... I don't think that is a disassembly that someone would do just for fun, but in a camera 50 years old a lot can have happened.
To start out, a few questions: does the rangefinder agree with the distance engraved on the lens mount? Does the infinity lock snap into place at the infinity setting? If the entire mount is 3/4mm too far forward, the front chrome cover should fail to seat fully into place on the body -- do you see signs of this not fitting properly?
If the lens mount and rangefinder look correct, another place where the focus could be upset is at the film gate inside the back: this is removable for servicing the shutter, and if it is not seated back into place the film would be pushed back away from the lens. If it's out by 3/4mm, you should see a visible gap along the bottom of the chassis inside the camera. Look for reassembly errors, not something to take a hacksaw to. |
Glenn
Tinkerer
Username: Glenn
Post Number: 1052
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 10, 2012 - 09:31 am: |
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Kevin,
No, any machining is from the mount/body interface and not from any 'face' that locates the dismountable optics. As Rick states the Kiev is usually reasonably constructed, so I would follow his advice and look for extra shims etc. Just one other suggestion - you state yours is a Kiev 4. So is it possible that in an earlier or a later 'series' the mount/helical assembly was actually thicker and your camera is fitted with the wrong assembly? As I stated I have no in depth knowledge on these Russian clones, but have come across very different mount machining specifications on a number of early Zorki and also FED bodies that I have worked on. No problem if you keep all the shims and mount ring with the original body, get the bits mixed up and getting an accurate flange to film plain distance always seems to end up in a shim cutting marathon! |
Hollenbj
Tinkerer
Username: Hollenbj
Post Number: 90
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 10, 2012 - 10:58 am: |
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The original post makes me think "rangefinder adjustment" more than anything else. That's not a difficult job at all. Start there. I'd be curious to see if that remedies the situation. Please report back. |
Wideopeniris
Tinkerer
Username: Wideopeniris
Post Number: 9
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 10, 2012 - 02:32 pm: |
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Thanks for the most helpful comments. I'll try to answer the questions from Rick...
The rangeinder is spot on against the engraved scale, at infinity, 1m, 2m, and 3m all fine. Just to be clear I have shot a roll of film and got every shot blurred from 3 lenses. I have checked the image at the film gate with lens on infinity and it only focusses correctly at 8ft. If you apply the thin lens equation this suggests about 0.85mm error (lens too far out) which is consistent (broadly) with what I measured at the flange to film plane depth. So we cant blame the range finder adjustment
OK. I put the cover back on and it fits OK - not obviously high. There is only a tiny gap at the bottom and it mates the leatherette like it should.
The infinity lock works correctly and clicks in snug when on infinity. I've removed the whole lens mount assembly and under it were one brass washer of about 0.1mm thickness under only three of the screws. I extracted the helical part - it all looks OK and there is only one way you can get the thread started that gets the infinity lock in the right place and leaves the distance scale looking right in the mount.
The film chamber looks OK to me, but I'm not very sure what to expect. There is a groove on the bottom where the top part meets the bottom, but at the sides it doesnt look wrong. In fact I just undid it and eased it open and it looks like its seating just fine.Also the rewind release pin is concentric in the hole in the upper casing (i.e. the bit with the film gate runners on).
The base of the lens mount (i.e. the large plate that holds the lens mount assembly) fits into the casing of the camera well.I wondered if the casting wasnt machined or something like that, but there is a little lip around two sides for the mount to fit into so it must have been machined..
A reassembly error is what I am hoping for - the idea of taking my lathe to part of the camera is not one I'm that happy with! |
Wideopeniris
Tinkerer
Username: Wideopeniris
Post Number: 10
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 01, 2012 - 03:10 am: |
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A final update on this issue!
I bought another body (fortunately these are cheap). Its immediately apparent that the lens mounts have been machined differently - so the original body was manufactured incorrectly - the inner bayonet is further out of the body and this is enough in error to be seen by inspection.
When measuring, the error is about 0.46mm. Problem found! so the camera has never taken a good photo in 50 years <sigh>
So the new one has a sticky shutter on 1/5,1/2 and hangs completely on B. So I now need to decide whether to fix the shutter on that one or swap the mount into the original camera....
Thanks for all the great suggestions - the help here is excellent. I suspect I'll be back again sometime...
Kevin. |
