''Snowflakes" on a Xenon lens....

A few days ago I posted a question about the ''snowflakes'' on the

lens of my otherwise mint Retina IIa. Some people thought it might

be a balsam fault, others that it might be fungus.

 

Doing some research on the web today I came across the following

passage on a Retina website:

 

''The one thing about the Schneider lenses (which appear to be vacuum-

coated, rather than coagulation-coated) is that they sometimes

develop tiny "stars" in the front element coating. This has no

effect.''

 

I am sure that the author is referring to same marks as I noticed on

on mine. Of course you have to take most things you read on the web

with a pinch of salt.

 

I just wonder whether anyone else has encountered the ''stars'' on a

Schneider lens?

 

Simon<div></div>

Simon,

I would be most interested in hearing comments on this "snowflake" phenomenon, too. I have a IIa at home and will have to check it. Now you've got me wondering about mine! I hope the fellow is right--I hope there's no adverse effect...

 

--Micah in NC

What is the URL for the Retina website? As a Retina fan and user, I would like to look at it.

This one:

 

http://www.dantestella.com/technical/retina.html

I can't see from the image very clearly, but the shape is suggestive of fungal growth- presumably you have eliminated this possibility.

That's fungus. If it didn't affect the light attempting to pass through the lens, I wouldn't be able to see it. I can see it because it is scattering the light. That's light you want on the film. The claim that "This has no effect" is incorrect. It has an effect to one degree or another. Another problem with the fungus is that you are seeing an ongoing process. If allowed to continue, the degree of its affect will increase proportional to the fungus population. Its presence will not enhance the value of the camera, but it will be a detriment to the photography you might attempt with it.

I took the camera to a local camera tachnician who has been in the business since before my Retina IIa was made.

He took one look and said the ''snowflakes'' are fungus but said it had been there a long time, isn't likely to spread unless the camera is kept in damp conditions and probably won't affect image quality unless I intend using the lens wide open a lot.

This may be true as the marks are actually only visible when viewed from an oblique angle His verdict was ''leave it alone''.

He also had a listen to the Compur shutter which is running slow on 1 sec and said that though he had all the spares and could service it, I probably wouldn't notice much difference in the results I get if mainly using the faster speeds.

I'll run a few films through it then decide whether to take his advice to leave it alone.

Thanks for all your help and a very Happy Christmas, Simon.

What he is saying then is that the coating was removed from the acid by-products of a fungus infection. All too common and only repairable if you polish and recoat the lens at great expense.

Looks like fungus to me. Without film in it, place the camera with the lens in a nice sunny spot with the lens facing straight into the sun (the stronger the light the better) for a day or two. That should kill it, and stop any growth. Obviously, don't place it behind anything that filters UV light out, like coated "low E" glass, etc.

So, everyone was right; the perfect outcome.

Let us see some pictures from the camera. I think the Xenon is one of the great lenses, though when I look through mine, I don't see much of a coating. I get much better results outdoors when I use a lens shade or a filter in the Series 6 adapter which also provides some glare protection.

It's easy to unscrew the front part of the lens by hand on a Retina IIa.

If the fungus is on the back it can be cleaned.

 

If it's between the elements this should be posible to kill the fungus it by placing it in hostile environnement what do you think about freezing it ? (I need your advice about it.)

<i>If it's between the elements this should be posible to kill the fungus it by placing it in hostile environnement what do you think about freezing it ? </i>

 

That sounds like a bad idea. Do what was suggested re: sunlight.

 

Freezing and subsequent thawing could introduce more moisture into the lens than you want. Kill it with the UV from sunlight.

Just a comment from a biologist. Freezing is unlikely to assure killing of the fungus. We freeze our microbes down to -80 to store them... alive.