Cleaning a enlargers condensers

[NDKodak]

Is it advisable to clean the condenser lens on my old Beseler 23C?
Does a dirty condenser lens affect things that much?
What is the best method? I was thinking warm water and a old t-shirt for a cleaning rag?

 

[Tom1956]

That would be fine. Warm water. a bit of dish soap, and dry with paper towel. Yes, dirt shows when you stop the lens down.

 

[Vaughn]

I use an anti-static plexiglass cleaner. I just happen to have a lot available. I use Photo Wipes, but any lintless cotton cloth will work fine. I set the condensers down on a clean soft surface.

Our Omega D5's need their condensers cleaned yearly (and sometimes more), the 23C's maybe every few years. This is in a high-volume university darkroom. The difference is due to the moving of the upper condenser of the D5's by the students depending on the formats the students are using.

 

[Newt_on_Swings]

Yes, its a good habit to keep them clean, but you dont have to go overboard with it. I usually take them out and use compressed air on them, and there are fingerprints i use a good bit of eclipse solution and pec pads.

 

[Vaughn]

To check if your condensers need cleaning, put a large white sheet of paper on the baseboard and with (or without) a negative holder in the enlarger (no neg, though), turn on the enlarger (I keep the lens open all the way).

Rack the focus all the way back and forth and look for dark specks on the paper. It helps to move the paper around a little as the black specks (dust on the condensers blocking the light) will be stationary as you move the paper.

Dust on top of the condensers will not be obvious when focused where the negative plane is, but sharpen up when the focus is racked to the extreme. These specks expand greatly when one focuses the negative and can show up in areas of even tonality as large fuzzy areas of lighter tonality.

Because the dust on the bottom of the condenser is very close to the negative, they are sharper.