Not specific to large format, but you guys are such a great resource, I like to pick on you... One of our high school enlargers has a big scratch on the condenser lens, bad enough it shows up when the lens is stopped down about halfway. Is there any fix for this, or do we just have an enlarger for parts?
Quick fix: replace the condensers with a cold light.
"I would feel more optimistic about a bright future for man if he spent less time proving that he can outwit Nature and more time tasting her sweetness and respecting her seniority"---EB White
You could try painting the scratch with black ink or non reflective paint. This may cut down the light scatter and allow you to use the lens.
You might try that eyeglass repair solution advertised on TV that seems to fill scratches with some sort of polymer. Or, you might see if adding some diffusion above the condenser would help. Otherwise, it may be a matter of finding a replacement part, or starting your own "spares" bin.
What do you have for an enlarger? If you have a omega D2 I may be able to help?
Dan
Turn the condensor lens 'upside down'!
The condensor lens is usually symmetric so this should probably do the trick. If it is contained in a housing you just need to unscrew it...turn them around...and screw it all together again.
...I should add that as you stop the lens down the 'scratch' will be included in the DOF above/behind the negative. By turning it upside down the scratch will be out of the DOF. The scratch on top of the condensor lens does not impact too much unless it is very bad. I have positive experience from doing this myself...it works until you have a new scratch...
First try putting on top. Second rotate so it is either close or far rather than left or right as it may be out of the image area.
Polish it out with very fine polishing compound. You start with a course grit to get the scratch out and then to finer ones so the dullness polishes away. Polish crosswise just the scratch area and remove as little as possible.
Lastly add a piece of tracing paper or diffusion material above the top condenser. This will soften the enlarger one half grade and reduce the light some.
Can't do a cold light; we use variable contrast papers.
Can't paint it black, it would show up even more. That trick works on taking lenses/enlarger lenses, but on condensers it's positioned to close to the negative and shows up in the image.
The scratch is in the center of the crown where the two crowns come together. rotating or swiching the lenses won't move it significantly.
Polishing the lenses may do the trick. You guys are great!
How about just removing the offending (ed) condenser altogether? As I remember Leitz/Leica always had a single condenser in their enlargers and it seemed to work fine? Wouldn't cost a thing. Probably put the good condenser flat side down next to the film.
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