Fogged Lensgreenspun.com : LUSENET : B&W Photo - Printing & Finishing : One Thread
I thought Id share with you a recent experience which had me stumped for awhile until I found the answer and this may assist others. I have been doing black & white for approx 10 years as a hobby. I have an Axomat Meopta enlarger which has served me well. Over the last 12 months I noted that my prints were loosing their impact. I had started to use a higher grade of paper to get the same deep blacks and in the areas were there were dark blacks and whites the black appeared to flare slightly and not have a sharp edge. I checked everything imaginable out including the method I develop the safe light and finally found after using a friends enlarger that it was my lens on my enlarger which had deterioted. Looking through th lens it appeared ok but when looking at an angle you could pick up small specks similar to fogging. I replaced the lens and Im back to printing sparpe clear deep black and bright white again.
-- Jim Wright (firstname.lastname@example.org), September 05, 2001
When not in use, keep your lenses out of the darkroom, or in air tight containers. Some of the fumes can attack the lens coatings. (At least that's what I read somewhere.)
Try cleaning the old lens to see if it's just surface junk. As someone who wears glasses, I can assure you that there is stuff in the air that gets onto my glasses. I'm sure the same occurs with enlarging lenses.
-- Charlie Strack (email@example.com), September 05, 2001.
If your enlarger is permanently kept under pretty humid conditions, there may be fungus on the lens. Quite often, such a lens is a clear write-off. Also, some chemical fumes may lead to pits in the lens surface (see Ctein's Post Exposure). Finally, greasy fumes (such as those from cooking) tend to deposit on all surfaces. These latter can be dissolved. Try cleaning the lens using lighter fluid.
Regards, Thomas Wollstein
-- Thomas Wollstein (firstname.lastname@example.org), September 06, 2001.
Thanks for your responses. What I failed to to say in my original post was that I have rectified the problem by buying a new lens. However thanks for the tips in making sure it will not happen again
-- Jim Wright (email@example.com), September 06, 2001.