Aero Ektar with spots on the glass, can it be saved?
So I got this lens from a friend who exposed it to too much light in order to clear the yellowish tint... the yellowish tint did go away but some spots appeared on the glass elements - in the front glass element they look like "blooming" and in the back glass element they look like stains.
See the attached photos.
My questions are:
1) how will these spots affect my image? I haven't tried the lens yet.
2) are they removable and if so, how do I remove them? If I take them to a local lens repairman, can he do anything?
I would be thankful on any replies on this matter... it's a nice lens and it is a shame to throw it away.
Re: Aero Ektar with spots on the glass, can it be saved?
Looks like classic separation of post-balsam 1950's lens cement. Possibly the light source used to clear the tea stain from radioactivity was too hot?
Yes, it can be cured, but you have to take the affected elements out, separate them, and reglue them.
Re: Aero Ektar with spots on the glass, can it be saved?
Quote:
Originally Posted by
Kevin Crisp
Looks like classic separation of post-balsam 1950's lens cement. Possibly the light source used to clear the tea stain from radioactivity was too hot?
Yeah, from what I know, the light source was too hot... shame.
Quote:
Originally Posted by
Kevin Crisp
Yes, it can be cured, but you have to take the affected elements out, separate them, and reglue them.
I am not at all familiar with this process - I mean, I can open up a lens, no problem, but separate glass elements, reglue them, etc, that's a feat far away from my abilities, mainly because I don't have the spare time (or spare work area) to do it. Is it an easy job for a professional lens repairman, or they don't meddle in such things? I've got a couple of guys here in Athens who repair old cameras, align lenses, etc.
In any case, how will this balsam separation affect the resulting image? Lowered contrast? Flare?
Re: Aero Ektar with spots on the glass, can it be saved?
You can learn to do it yourself, but there is a learning curve. If you can unscrew a retainer or whatever and email me a photo of the element with the separations, I can try to walk you through it. Hopefully the diameters of the two pieces of glass that are glued together are the same; otherwise, it complicates things.
There are UV lights that CF bulbs that eliminate the potential for this since they barely get the lens warm.
Re: Aero Ektar with spots on the glass, can it be saved?
What materials do I need in order to separate the glass elements and then glue them back together?
Re: Aero Ektar with spots on the glass, can it be saved?
You have to take the cemented lenses and put them into cold wather and slowly heat to max 80 degree celsius (lenses musn't touch the bottom of the pot) Let them cool slowly - you have to repeat it several times. Canadian balm should dissolve in to the water. Then recement the lenses. If you do it to fast It will destroy the lenses... I done it one time with aplanat lenses...
Canadian balm is easy to buy
Re: Aero Ektar with spots on the glass, can it be saved?
There have been recent suggestions that boiling water will do it, with the temperature raised very slowly. I haven't tried that. I have used soaking in solvent to do it, but that doesn't do it very quickly. (On the other hand, there is no chance of breaking the glass.)
You need to then clean the glass off with very clean acetone, reglue with UV curing lens cement, and then set it with UV light. Summers Optical has lots of information on this.
Re: Aero Ektar with spots on the glass, can it be saved?
There is an old link at SK Grimes about recementing. That plus the info at Summers Optical should be plenty, supplemented by the info here. I used heat to soften the balsam to allow the elements to be separated, which is another method.
Re: Aero Ektar with spots on the glass, can it be saved?
This isn't balsam separation though, from the looks of it.
Re: Aero Ektar with spots on the glass, can it be saved?
I will try the lens first against a different, clean, Aero Ektar I borrowed in order to see how much this cementing degradation (whatever it is) affects the final image. Hopefully I'll do it tomorrow, maybe some studio still life shots and some kind of landscape. I'll let you know about the results.