Help! Is this decementing?!?

[ocean7]

Greetings to all,

I recently sold my M6 to cover some expenses but after that I realized I was missing so much owning a Leica. I found then a button rewind M2 on photo.net and after a few emails back and forth with the seller I purchased it.

He sent me a few pictures and even though I am aware of the prism decementing phenomenon I am no expert so I guess I did not look close enough.

I am still awaiting delivery and the seller gave me a return privilege but tonight looking at the pictures again I started to freak a bit...

http://www.pbase.com/ocean7/image/90135539/original.jpg

So what do you think? Decementing or not?

Thanks so much in advance for the wisdom.

 

[Bob_McBob]

That golden-coloured crust is what I've always though of as "decementing," but perhaps I'm wrong. My M2 had it all around the prism, and so did many others I looked at when I was originally buying it. Some were definitely worse than others, and yours doesn't look too bad. It's not a problem unless the two parts actually come apart, which is generally due to a shock like being dropped. I'm pretty sure CRR Luton and others can now recement dead prisms with modern materials, but it is not cheap. Always a concern with the M2 and M3...

 

[Bob_McBob]

P.S. You can sort of see it in this photo: http://www.pbase.com/image/57749655

 

[Bryce]

Is re cementing elements really that hard? There was a post here not too long ago about someone placing a decementing lens group in a warm place and letting the cement (Canada Balsam?) liquify and re solidify.
Maybe I'm mistaken, but that doesn't sound like an awful job other than getting the prism out and back in again.
Or is there something different about this situation, like something other than the cement has found its way between the pieces of glass?
Or maybe the cement is not Canada Balsam and cannot be remelted?

 

[Bob_McBob]

Here's a quote from DAG: "Many M3 main prisms have a border of "glaze" around their main prism & optically it's as good as new. When & if the prism starts de-cementing into the main prism area then it's a good idea to re-cement — which costs $US 200.00."

From CRR Luton: "This is the normal balsam separation found in many M3 cameras . It entails heating and removing the prisms & separating the optic , cleaning and recementing. The rangefinder then has to be re-aligned & recalibrated."

http://www.angelfire.com/biz/Leica/images/vf.jpg

 

[Krosya]

Hard to tell based on the picture you posted. But I think it looks that way.
Up-side - it may not get worse ever as long as you are careful with it and never expose it to any shock - drop, etc.
Down-side - it can make VF less bright and harder to focus and if it does break - might as well get a new camera, since fixing VF is very pricey.
I'd stay away from it, as you can find a M2 in much better shape.

 

[Ororaro]

Well, 200$ isn't too expensive for reviving an M2 or M3 once it's decemented. From what I know, even if the picture you're showing is decementing, it can take 10 years oreven 20 before it goes all the way. I say use it 'til it dies. You just might end up using it for 10 years without a problem.

 

[Stu W]

Philippe, I'll bet the camera is just fine and you're losing sleep over nothing! Just go to any camera show and examine any Leica close enough and you're sure to find something. Post some pics of the new baby when it comes. Stu

 

[MikeL]

My M4 prisms look worse, and I've banged my bag around, and for 3 months of the year I'm driving on bumpy dirt roads. The viewfinder is almost as clear as the modern ones. If it's clear, I wouldn't worry about it.

 

[HuubL]

My M4 prisms look worse, and I've banged my bag around, and for 3 months of the year I'm driving on bumpy dirt roads. The viewfinder is almost as clear as the modern ones. If it's clear, I wouldn't worry about it.

But the M4 prisms aren't cemented with canada balsam, but with an artificial glue, which isn't degraded with time that much.

OTOH, my M2 shows the same golden streaking. No problem whatsoever thusfar.