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02-20-2015, 07:28 AM   #1
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Weird mirror issue... looking for some insight/ideas/help...

Here is a problem I have never encountered before and I can't figure out why it happen and how could I fix it...
I have this issue on 2 Ricoh cameras... I'm baffled...

A couple of weeks ago while going trough my cameras and testing them to make sure everything still clicks and works properly, and giving them a clean up in the same time, I noticed that 2 of my cameras started to have some very weird issues... At any speed, with the lens on, it seems that the mirror goes up but never returns to its original position. It only returns after I remove the lens from the body.

These 2 are manual cameras so no fancy electric motors in them. At first I thought it was the lens, the aperture lever might be stiff on them so I went through a few other lenses and encountered the same problem.

I struggled in trying to find out what might be the issue for a couple of weeks now and last night I think I have finally figure it out!
One of the lens got slightly stuck and had to force it a little to take it out and I heard something scratching. I looked at the back of the lens and noticed a scratch on the ring that holds the rear element in place. I look inside the camera and I noticed shavings under the lip of the mirror, stuck to the mirror. That's when I paid more close attention tot he mirror and... to my astonishment I realized that the mirror seems to have slide down on its bracket and now when it moves up, is further away towards the outside of the camera and its hitting the lens, getting stuck in there.

How could this happen!? The mirror is glued on and it doesn't seems to move when trying to push it up, back in its place. If I force it too much, it feels like something will easily break for sure. And this happened on 2 cameras...

Last summer I used both cameras without any issues, so I know that last time I've put a film through them everything was good.

Any ideas why this might of happen and how I might be able to fix it?
I'm a little bit stumped to be honest!

02-20-2015, 07:43 AM   #2
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It does sound like whatever was holding it failed and it moved down by the force of the mirror (and may now be stuck in a new position, but still wrong).

I have no idea if this is the case here, but one interesting thing I've noticed with older equipment is that sometimes whatever grease or glue they were using at the time seems to have a very definite and specific lifetime, e.g. something like exactly 28 years after a batch of lenses was manufactured the grease breaks down and suddenly every copy of that lens you can find has sticky aperture blades when they were all fine 5 years prior.
02-20-2015, 08:27 AM   #3
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The thing is, if the glue is the problem, it had some interesting characteristics. It had to get to a point where it lost is glue properties just enough to allow for the mirror to slide down and then got back to acting like a glue... those mirrors are solid and it doesn't seem like you can move them easily...

Anyone knows what type of glue they might of used back then?
Could I use a heat gun to heat up the mirror and glue slowly while trying to push the mirror back in its place?

Btw, if it helps in any way, the cameras in question are:

Ricoh KR-5III


Ricoh KR-30SP Program

Last edited by mrNewt; 02-21-2015 at 12:11 AM.
02-20-2015, 08:54 AM   #4
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If you want to return a thermal adhesive to its "open" state, do it slowly. Try setting the camera in bright sunlight to see if it warms up enough. Heating it quickly might not hurt the adhesive, but the amount of energy required to do it quickly is likely to roast the camera.

02-20-2015, 08:59 AM   #5
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Around here, sun might be an issue this time of the year... is -23C outside .
The only option I have is a heat gun.
02-20-2015, 02:22 PM   #6
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Most of the cameras of this age have the mirrors stuck in place with double sided adhesive tape, if the camera has been stored in very warm conditions then it is possible for the adhesive to soften and let the mirror slide.
I would certainly not recommend that you use a heat gun because this would probably crack the mirror and cause other damage within the camera.
Put the camera somewhere warm for a few hours so that the glue softens again and either slide the mirror back or using a very thin craft knife or a scalpel you will be able to lift the mirror off the supporting frame.
Removing it and fixing new adhesive tape would be the best way but any tape you use must be the same thickness as the original or the the focus position will be affected.
02-20-2015, 02:57 PM   #7
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Well, obviously, if I'm going to use the heat gun I'll use "better judgment" and not put the heat gun right on the mirror.
I'll leave a fair amount of distance and slowly heat it up, on lower settings.

Last edited by mrNewt; 02-25-2015 at 09:07 AM.
02-20-2015, 10:49 PM   #8
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I have the same problem with a Ricoh KR30-sp so it may be fairly common. I haven't messed with mine because I have two of them.

02-20-2015, 11:22 PM   #9
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You may also find that removing and re-taping or re-gluing the mirror may change it's position which may affect what appears to be in focus. Put your 50mm lens at infinity and aim the camera at something far away to see if the focus looks right.
02-20-2015, 11:36 PM   #10
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QuoteOriginally posted by mltain Quote
I have the same problem with a Ricoh KR30-sp so it may be fairly common. I haven't messed with mine because I have two of them.
I guess is good to know that this is sort-off "normal" for the KRs.
Not in a rush to fix it right now, so in the mean time I will try and find the best approach on how to fix this.

QuoteOriginally posted by pentaxus Quote
You may also find that removing and re-taping or re-gluing the mirror may change it's position which may affect what appears to be in focus. Put your 50mm lens at infinity and aim the camera at something far away to see if the focus looks right.
The focus hasn't been affected. The mirror is basically still at the same angle and "height" inside the box. It just moved/slide 2-3mm lower. Even the image inside the VF seems look the same (nu cut offs). If the mirror will not get stuck on the lens, it would not bother me at all.

Not planning to remove the mirror. If I can get to bring it to the right temperature and just to move it/ slide it slowly back without actually lifting it from its frame, it will be just perfect.
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