Lens separation

[bucs]

Ive discovered very recently that my summitar has lens separation. About 1/3 of the rear element edges have this tint of haze.

I will be testing it out soon and if the images are usable i will leave the lens as is. In the long run however if the lens is no longer producing pleasant images, what are my options to have it repaired or recemented?

Thanks

 

[bucs]

Here's an image of it

http://flic.kr/p/q2aPND

 

[sevo]

The picture at least does not show any separation - the haze visible there might be mold, or just dust and condensation.

 

[hamradio]

I also don't see any separation there.

Even if it does exhibit some, more likely than not it would work just fine. I don't think Summitars are usually bought for the reason of the best technical performance, anyhow...

I have a Schneider Angulon 90/6.8 that looks awful...about half of the front cell has very obvious separation. A big flare when pointed at the sun is present on the ground glass wide open, but disappears completely at f/8. I never use it larger than f/16. The images from that lens are as sharp as I could ever ask for, and I've never had a bad negative from it that wasn't caused by user error.

The same goes for a Mamiya RZ 110/2.8 I picked up for a song due to some fungus. I cleaned the fungus out and then noticed some elements in the rear cell are separating around the edge. I haven't noticed any ill-effect on images, despite the glass looking slightly horrifying.

 

[Pioneer]

I have two 85mm Contaflex lenses, one with obvious separation, one without. At 5.6 I cannot tell the difference between the lenses. I'm sure there is some degradation but without enlarging way past reason it seems to have no visible effect.

Besides, as mentioned, none of us are shooting these lenses for the ultimate in sharpness anyway.

 

[View Range]

Separation can be repaired (re-glued) by lens repair shops. In the US the choices I know of are Focal Point near Denver and S K Grimes near Providence. Focal Point has a nice web site that discusses various lens issues and the repairs involved.

 

[rawhead]

I recently de-glued, CLA, and re-glued a couple of lens groups. Wasn't really that difficult, once you get over the fear 😀

The process went like this:

1. Slowly heat the lenses in an oven up to 260˚F or so, when the Canada balsam softened enough to separate the lenses
2. Very slowly cool the lenses in the oven
3. Thoroughly cleaning the lenses & removing the goo with acetone & isopropyl alcohol
4. In my case, I had hazing that wouldn't go away, so I had to go extreme and do some polishing with cerium oxide
5. After all the above re-bonded the lenses using a UV-cured optical bond

Total cost around $40 and maybe 10 hours total of my time 🙂

 

[sevo]

1. Slowly heat the lenses in an oven up to 260˚F or so, when the Canada balsam softened enough to separate the lenses

That will only do with Canada balsam, and (with higher temperatures and greater risk) with modern UV-cured cyanacrylate cement lenses. There was a intermediate period (depending on the maker starting anywhere between 1940-1960 and ending in the sixties to nineties) where epoxy cements were used. These are not thermoplastic!

 

[John Shriver]

I'm with Sevo -- that's just haze. Doesn't even look like fungus. Looks like you have an uncoated Summitar, so any of the usual Leica repair folks will be able to clean off the haze. (Haze in a coated Summitar is a bigger problem, often cleaning off the haze removes the soft lens coating on that surface.)

 

[Gareth Rees]

Try it and see.