(Balsam) Seperation

[Nightjar]

Hi there,

I just received a Contax 100-300 lens.

Sadly ther is a slight (balsam) seperation in the inside... (looks a little bit
like a fingerprint)

1.) can it be fixed by lens repair experts (with a adequate price)

2.) how much does it affect picture quality?

Thanks for the tips.

Cheers
Nightjar

[newst]

Some people have accomplished the repair of a balsam separation by a process that heats the glass until the balsam used to glue the lenses together until it melts, separate the glass, clean it and re-glue it.

1. I don't know how involved the process is, but I assume it isn't cheap and/or easy.

2. It only works if actual balsam is used as the original glue. There were other adhesives used besides balsam and I haven't a clue what was used on your lens.

[Lightshow]

Can you post pictures of the lens and the area of concern?

[Lloydy]

someone here on the forum uses an easily available glass bond, something you buy from a DIY store in a tube, to replace the old balsalm. I bet a search of the forums will turn something up.

[Gerald]

[jamaeolus]

I have read that some solvents IIRC xylene will dissovle the canada balsam. so no need to heat it. It was as I recall on a large format forum. Canada balsam can be purchased online as well. Depending on your enthusiasm and handiness level a DIY project.
see here:

http://www.largeformatphotography.info/forum/showthread.php?88365-Lens-Repair-My-lens-elements-have-separation

[calvin83]

There is no glued elements in the Contax 100-300. It may just a fingerprint as you see?

[Nightjar]

I'll certainly not do DIY as this lens was almost 1000$.

You say there's nothing glued? I'm sure there is nothing like old balsam,
but maybe the new sythentiv UV technic (or whatever that is called) was
used?

Here a picture:

[edri]

I asked on the phone a few days ago at a lens service about the cost of repair if the lens elements are separated because of Canada balsam. The answer was that a professional repair cost about 200euro, but depends on the lens, can be more. The man at the service asked me if indeed it is about separation, if I see Newton's rings ... I had no idea what he was talking. I actually asked about a lens I wanted to buy and that is prone to such defects. The conclusion of the man form the service was that it is wise to repair for this only expensive lenses such as Leica or Angenieux.

But on other forums I saw that there are people who know how to repair at home in an artisanal way such a problem. I do not know if afterwards the lens longer fit into the original optical parameters.

[dan_]

I fixed some separation issues, but only on older lenses, glued with Canada Balsam. The Canada Balsam is more forgiving than the UV glue. The most difficult part is to center the two lenses while gluing them and to get rid of the tiny bubbles in the balsam. For a perfect centering a special part should be made. You can easily take apart the glued lenses and glue them again if you are not content with the result. The balsam needs 1-2 weeks to harden completely.
If done correctly the repaired lens doesn't lose its optical quality.

But, as Gerald said, most likely your lens is not old enough to use Canada Balsam.

[calvin83]

OK. I check again there is glued elements in the middle group. I also get information from a repairman that it is comment to see separation on this lens especially the rear element.

[Gerald]

According to Zeiss, this lens has 12 elements and 7 optical groups. This means there are five cemented groups plus two single-lens groups.

The OP should check if the separation is real (I'm not sure if there is separation; perhaps it is only a stain on the coating), and if it produces any visible effect on the image. Maybe it's better to let the lens as it is.

[Himself]

As long as it doesn't have any impact on the pics quality I'd leave it as it is.
Opening up a zoom is tricky. Putting everything back together could be a nightmare.
I opened up and fixed some primes but I wouldn't touch a zoom. Especially a Contax.

[jamaeolus]

My (decidedly amateur) opinion is there is no separation apparent in the photo. I would just use it.

[francotirador]

I happened this with a tokina zoom, F3.6 28-135. I cleaned the glass with isopropyl alcohol and then to unite them again use UV Glue. Perfect result !!!!

https://www.facebook.com/profile.php?id=100009122463840&sk=photos&collection_token=100009122463840%3A2305272732%3A69&set=a.1492280197752715.1073741843.100009122463840&type=3

[ZoneV]

[Paulius]

Live it as it is, separation can't produce any significant harms to your image. Taking apart zoom is a can of worms.