Wednesday, 23 March 2016

Sticky Problem with enlarger

The subject of this post is a bit off target for a Leica themed site and indeed it seems strange to be writing  an historical study of a piece of equipment that was in day to day use by Amateur Photographers only, it seems ,yesterday.

Who can forget the Zenith Enlarger, also styled UPA-5, and  the various Cyrillic versions? Many may well wish to! Reputed to be a Zeiss design, I found one hard to resist on Ebay and it came to me for 0.99p and a token sum to Hermes.Needless to say it had decayed foam in the case and it is over this that I intend to take up your next few minutes.

When new these enlargers were sent out in a case that forms the baseboard. This is an essential part and it was only in the last few issued that a conventional baseboard was supplied - and the code moved first to UPA-601(using the box as base) and later to UPA-E with both baseboard and case! These later versions were not officially imported, as far as I can tell.The baseboard/box was lined with a cream foam rubber lining with the location of parts printed for ease of repacking,Over the years-time and the river flowing-this foam decays in the same way that the light seals on some SLR's will do,However,while a sticky camera is a problem to fix just imagine how bad is a box about 15" x 20" fully lined with what is now a material with the consistency and colour of melted cinder toffee. Given that Russian paint seems so fragile the choice of a solvent to remove the 'gunge' was important and, after tests, Lidl Brush Cleaner(-Xylene) seemed best.The good news is that degraded foam does not attack plastic or any paintwork so the task proceeded as follows.

Find some rubber gloves.
Scrape the old foam out with a plaster knife.
Get to work with the solvent -outdoors- with kitchen towel-about a mile off the roll should do.
End up with a clean case and a filthy enlarger.Repeat treatment on Enlarger.A light coat of Isopropyl Alcohol removed any residual sticky feel from the metal parts.

The important bit,the enlarger, cleaned up well with the solvents and shows no sign of corrosion after 40 years with bright metal as new. A lens was found in the inner workings which was unmarked and free from mould as were the spare negative stage parts in the original packing. It is suggested on some web pages that the lamphouse is prone to light leaks, but not so in this case,the handbook refers to an improved design of baffle.

Mention of the lens brings me to the instruction manual which clearly states this to be three element. I was unsure if this lens was based on the Industar camera lens which can be quite good but it seems to be a one off design for this enlarger. The Industar -22 in four element design and enlarger mount seems to be still available on the S/H market in coated form.I had thought I should really have a four element type at least and  set up my model with a 50mm Ross lens (Made in UK) which is in a short mount and needed little adjustment. In fact I am using manual focus all the time as I do like to make a second check of focus before going to print.

I am now faced with two choices, either:

    -re cover the interior with card or foam       

-slam the lid and keep the base as a base 
 NO CONTEST! I don't expect to display the enlarger as a design object and it can stand in a row with my other user enlarger, having acquired a dust cover(polythene bag)

The selection of lens has given me some thought. I now realise that as the standard lens lacks any click stops it is difficult to avoid moving the focus mechanism unless the iris is very loose. I found  the two Ross lenses I fitted very stiff in comparison and have settled for a Durst -Schneider Componon 50mm f4. six element,The important factor being the choice of a lens of modest size.This alternative required fitting by trial and error but it became clear that the extension tube required was 7.5mm deep which I made up from a Reid and Sigrist 6mm tube and a thread adapter for the lens.One has the same issues with Leica where a DOORX goes between lens and enlarger. 

This is the case as arrived covered in decomposed foam


And the finished job-after clean up- in my Darkroom.
The upgraded lens is a Durst/Schneider f4-

It is clear that any replacement lens will introduce errors into the Auto Focus mechanism but one can revert to the original installation in a few seconds.The masking frame shown is about the same as the Russians supplied with some enlargers and completes a nice compact set up.