I just got off the phone with Christine at StoneMills. After looking through her inventory sheet she came up with three filters, one of which might be the UV filter I'm looking for. The first two are for the cls2000 but I'm thinking they might be the same filters used in the cls1000 and the cls1840 - "base filter...part #AA98340" and "heat protection filter...part #AA98429". They do have a UV filter (part #AD58304) but they're not sure which enlarger it's for. Anyone have a parts manual for either the 1840 or the 2000 so that I can positively ID these numbers? Thanks, frotog.
Ask Christine to measure the filters, and then compare it to your filter size. Any UV filter should work, as long as it physically fits the space. I don't have my heads open to compare, but I think the CLS1840 and CLS2000 share the same filter size.
I removed the diffusion plate. It is covered with the same sticky oily and sour to the taste substance that I suspect caused the uv filter to crack in such a bizarre pattern...in any event I need to clean it. Eric, once I remove the four screws will those little spring-loaded glass rods come flying out? I guess I'll use dilute rubbing alcohol or a windex-soaked paper towel to clean the filter.
When I pulled the magenta filter I noticed an aberration on the dichroic surface. Am I nitpicking in thinking I should try to replace it too?
Those 4 screws should release the diffusion filter and frame assembly, and the rods should remain together within the frame. Any cleaner you mentioned should work, or just soap it up good with dishwashing soap and rinse. Then blow it out and let it dry.
Originally Posted by frotog
I would not worry about the dichro filter. Remember, the light goes though the diffuser, and then through the plastic diffusers in the mixing box. A few blemishes shouldn’t hurt.
But I would clean all the dichro filters, and the IR and UV filters, before I reassembled the enlarger head. I cleaned all my filters by removing the glass from the frame, and soaking it in warm water with lots of dishwashing liquid. Rinse it off in warm water and blot with a paper towel. By being warm, the glass dries fast.
One other thing…… Those dicro filters have an “up” and a “down” side, and I think the only way to tell is by the appearance of the reflection when you hold them at an angle to a light. So when you remove a filter from the assembly, look at the reflection on both sides and determine what the “up” side looks like. Then be sure to reinstall it with the same reflection “up”.
Positively grateful for these essential tips. Thanks!