Leica LTM 50mm Elmar overhaul/re-cement?

[MC JC86]

I recently bought a 50mm 3.5 Elmar. It's uncoated, minimum aperture f/18. It looked clear when I bought it, but upon closer inspection with a light it has concentric circles, which I've been lead to believe is a sign of seperation. It also has some slight haze. I got some pictures back from it, the color ones are much lower contrasted (even compared to other, uncoated Leitz lenses I've had) I want to get it overhauled I think..
My questions are:

1. Are the circles definitely a sign of separation/decementing?

2. Is John Van Stelten, Focal Point, still the best place to go for work like this? It's the only place I have experience with in the past.

3. Has anyone had a bad experience having this done? I.E., IQ not improving, or getting worse?

Thanks for any and all help!

It still performs OK for B&W

(now I just have to correct my IICs shutter problem)

 

[Melvin]

Couldn't you just buy another Elmar for less than what it will cost to have that one repaired?

 

[MC JC86]

I could... but it most likely wouldn't have been professionally cleaned and may even suffer from similar problems. Not that I have lots of money, but I'm willing to invest money into my classic gear to insure predictable, quality results. I like the cosmetic condition of the one I have. I'd rather have mine restored as long as it will restore it's functionality near 100%. In my experience, buying another used item to replace something you have just because the repair isn't cheap doesn't always make sense.

 

[jmcd]

Two overall nice Summitar's have come my way over the past few years (one has moved on), but the both had separation between the front two elements, a common problem. Looking at the lens from one angle, the glass looked perfect. But catch it at another angle, and a milky segment of a circle clouded about 25% of the lens area.

Since the second lens was in such nice shape otherwise, but the separation was getting progressively larger, I sent it to Focal Point. The whole process took about two months and the lens returned late last week looking just beautiful. I am now hoping the lens will be in excellent shape for some time to come, and I am very happy to keep it in service—they just don't make these items anymore. So hopefully this will be around for some time for me and hopefully someone beyond me to enjoy.

John at Focal Point was a pure pleasure to work with—what an amazing craftsman. I am just amazed by people who take on such work and follow through gracefully. Any questions I had along the way he was prompt to answer via e-mail. When he first received my lens he was prompt to let me know that my lens had arrived and provided me with a cost estimate.

Still looking forward to finishing the first test roll.

 

[MC JC86]

Thanks a lot, that's encouraging!

 

[Wlodek]

The cement used in early lenses (and up to quite recently) was Canada Balsam. The separation occurs when it dries. It is often possible to redissolve it by heat. I did it successfully on a couple of occasions. One needs to unscrew the defective assembly and to place it under a source of heat, a lamp or radiant heater. When it is quite hot (difficult, but not impossible to touch) the separated elements are squeezed together and will likely join. Another trick is to put a drop of xylene on the edge of the cemented pair.
But please do not hold me responsible if you attempt it and fail.
Still, the best remedy is to remove the old balsam and to re-cement the lenses with fresh balsam or one of the more modern optical cements.