Durst L1840 Enlarger 8x10 10x10--Everything you wanted to know...

[Thodoris Tzalavras]

So, I reopened my CLS 2000 head, in order to take some pictures of the IR filter in position 32.







As you can see, this filter is actually part of the light bulb / dichroic reflector assembly.

(Just like in the head of the Durst HL 2501 AF, which I shared in post #882).

It's completely separate from all the other filters, and is held in place by a spring loaded metal frame.

The dimensions of the filter in my head are 108 x 108 x 2.3mm
(but a 3mm thick filter could easily slide into position)….
It's colorless when you look through it, but light reflected at 45 degrees has a slight magenta hue…



The reason why I asked for confirmation from other users, is because my enlarger came to me used and somewhat abused, with several alterations…

My Magenta dichroic filter is damaged, and I considered the possibility that the filter in position 32 might not be original, or that (even though visually in good condition) might not cut enough thermal IR radiation to properly protect the color filters, because of age or other reasons…

So, if someone could confirm that the filter in their enlarger has the same dimensions as the one in mine, it would ease my mind when ordering a replacement, since the odds that 2 enlargers with different ownership backgrounds should have the same non original filter are, well, very low…

Add to the equation the mention in the CLS 2000 manual that there are 2 IR filters in position 32, and the necessity for my question was born…

I understand that completely opening up your head to check for the answer to my question is a non starter, but I hoped that someone might already know the answer…

Alternatively, someone might be willing to remove the lamphouse cover (by pressing the two studs), take the lamp out of the way (by removing the two thumbscrews), and remove the dichroic reflector (by pressing one more stud)… then look down, towards the color filters, and see if the first filter (colorless) looks to be one piece or two…



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In any case, and assuming the absence of confirmation:

I'm considering ordering a 3mm thick IR filter (assuming I can get one…).

Does anyone know of any reason that I should avoid a thicker filter?

[Thodoris Tzalavras]

Just inspect your own one. If there are clips and a recess for a filter under the shutter. As in the first foto that ic-racer shows.

Here is mine Gary:



It looks exactly the same as ic-racer's in post #887

[sculptorBradP]

A little late writing here for the timeline.... Is the Durst UNIPLA lensboard the correct lens board for mounting a Schneider Componon-S 300mm f5.6 lens without any additional adaptors onto the position on a Durst Laborator G 184? I moved my whole enlarger in one piece unit Durst Laborator G 184 in the back of a Dodge Cargo Van from Chicago to Baltimore City, Maryland. Any recommendations on how to properly dismount the base, and possibly the lower heavier vertical double legs to get the two or three parts up three flights of twelve-foot ceiling floors...

, - Thanks, - Brad

[Andrea Gazzoni]

Brad, with a mount of 77mm you will need a Vapla lensboard. Lenses up to 72mm mount can go into the Unipla, but you'll need the proper Lapla adapter ring.

[ic-racer]

Agree, Vapla is the way to go.

My 360mm Componon mounts with a special flange. My 300mm Rodenstock uses it's flange as a retaining ring. Either way works.