Contax mirror slip consequences

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Vaidotas

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I just bought Contax 139 MA with Yashica ML 50mm f/2 and after quick check found that camera don't focus to infinity. It focus to max 5 meters.
Checked the lens on proper working Contax 139 and it appears the lens has no issues.
After visual checking mirror chamber there is obvious mirror slip to ~1-1.5 mm
There is a lot of threads about Contax mirror slip and how to deal with it but not much info about this malfunction consequences.
Question is - does mirror slip affects ability to focus in to infinity?
Or there is more than one problem?
 

koraks

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Question is - does mirror slip affects ability to focus in to infinity?
Or there is more than one problem?

The consequence is that when you focus using the viewfinder, the focus will always be off from what the film sees. So it's a problem that needs to be fixed if you want any of your photos to be in focus.
 
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Vaidotas

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Koraks, thank you for your thoughts, but we are still at zero point and my question remains unanswered.
 

koraks

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Perhaps someone else will come along and formulate the answer in a different way. Something is clearly lost in translation.

Good luck with the camera and I hope you'll find a fix.
 
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The consequence is that when you focus using the viewfinder, the focus will always be off from what the film sees. So it's a problem that needs to be fixed if you want any of your photos to be in focus.

Koraks, thank you.
There is question again.
Does mirror slip affects ability to focus in to infinity?
I understand your statement, you are talking in general.
My question is very specific for a folks who had this problem. Are you one?
So - mirror slip affects vignetting in viewfinder, sometimes has a contact with lens bayonet, and misalignment between film plane and viewfinder.
But does it affects inability to focus in to infinity at this degree (5 meters max viewing through viewfinder).
 
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Vaidotas

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Ok.
I left the camera at repair shop for mirror reglueing / calibration and promise to report how it goes within month.
I was a bit desperate with my questions just because in urge to make quick decision leave it to myself or return to seller. Apart mentioned problem camera is really neat.
 

gone

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Mirror slip does seem to be an issue w/ your camera. The link below gives you info on a do it yourself repair, assuming that is your issue. It also could be that the lens has been apart at some point and wasn't put together again properly.

 
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Thanks, momus.
The lens is ok as I stated in first post.
Thank you for the link, I read it and a lot of other sources before starting this thread as I stated in the first post.
 

ic-racer

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I had a Yashica FX3 in which the mirror was not inserted correctly and I re-positioned it. I have never had one move on me. If the focus is off, maybe someone tried to re-attach a mirror with 2-sided tape that was too thick.

Also, the mirror adjustment is shown in the diagram here from the Contax manual (which also applies to the FX-3).

 

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I had a Yashica FX3 in which the mirror was not inserted correctly and I re-positioned it. I have never had one move on me. If the focus is off, maybe someone tried to re-attach a mirror with 2-sided tape that was too thick.

But that would make the lens focus past infinity. Not reaching infinity means the mirror is too far back, doesn't it?
 

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If the mirror is attached with too-thick tape or is similarly displaced forward when it slips, then when the lens is set to infinity on the focus scale, it's correct for the film plane, but it cannot get close enough to the ground glass to appear to focus at infinity. That is probably what the OP meant by the lens doesn't reach infinity focus.

Edit: This is backwards as noted by brbo below.
 
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brbo

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Too thick a mirror or mirror attached with too thick a tape will be closer to the lens and ground glass - image will be focused past infinity on the ground glass. OP has an opposite problem.
 

reddesert

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You are right, in that case, if the lens was extended (say 5 meters on the focus scale), it would appear to be focused at infinity on the ground glass. So we are back to the question of what the OP means by "camera doesn't focus to infinity." On the focus scale? On the GG? etc.
 

Don_ih

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Contax 139 MA with Yashica ML 50mm f/2

The ML 50 is not very well made (although it's a very good lens). Without much effort, one of those will unscrew from its helicoid when you focus on something up close. If that happened and someone screwed it back together, it may not be together correctly. You need another C/Y camera to check it.
 

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Very astute of you to point out my oversight, @brbo . Did you happen to have any ideas?

If the lens is fine, the mirror mount has probably been bent by someone playing with it (flipping the lens up with their finger or perhaps attempting to push a slipped mirror back into position). However, if the ground glass is in upside-down, that might have an impact. Don't know if the focus screen is removable on the 139MA (?) .... did you mean 137MA?
 
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brbo

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Problem with bent mirror mount would be rather easy to identify, the upper and lower part of the image would not be focused in the same plane on the ground glass.

All is pretty much irrelevant now, since the OP doesn't have the camera anymore at hand and also asked for people that don't know this camera not to comment in this thread...
 
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Vaidotas

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The Contax 137 MA camera is on my hands after mirror regluing, callibration and cleaning.

The problem was improper attempt to reglue mirror with wrong thickness of dual adhessive tape. By slipping, mirror accumulated glue residue more at the bottom of mirror support causing change of the angle with pentaprism.

Thanks everybody for brainstorming.
Now I’m going through first roll, nice camera, very comfortable but my thumb still looks for rewind crank.
 

Yashica

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Hi Guys,

i pull this thread out again...my bad. :smile: I own a Contax RX (besides other 35mm Contax gear) which does have the messy mirror slip.
Do you know a decent camera repair shop, which could do this for a sensible price into germany ?

Thanks in advance.

PS: great to hear, the 137 MA is working. I own also the 137 MA & MD, one is wrapped into red artificial leatherette, the other into blue.
 
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