glass over condenser on a focomat 1C

dickgillberg · Nov 26, 2018

I just bought my third Focomat 1C, only because it had the filter tray that I miss on my other focomats. It have a glass over the condenser, why? Is it a mod done by the other owner or should it be like that?

Thanks

choiliefan · Nov 26, 2018

If it's a glass ring positioned over the condenser where it meets the negative holder, you have an anti-newtons rings adapter. The adapter should have an "N" stamped on the side.

Hilo · Nov 26, 2018

As choiliefan says, this round AN glass in the black metal ring slips over the condenser. The glass is AN treated and prevents Newton ring. The glass is 3mm thick and you will probably also find a 3mm braz spacer ring inside the condenser house, on the ridge the condenser is resting on. There is also often a very thin spacer ring there. Just keep it under the 3mm ring.

dickgillberg · Nov 27, 2018

It has the anti-newton glass also but this round glass sit in the lamp house just over the condenser.

guangong · Nov 27, 2018

Folks used to do this with condenser enlargers. The ground glass was supposed to reduce contrast and appearance of dust. Tried it in the late 1960snfor a couple weeks and didn’t like results. I guess you can do your own comparisons. What can be helpful with Focomat is the adjustable negative stage kit with tilt able easel.

chip j · Nov 27, 2018

It's for a special bulb that was made long, long ago, I believe. This very topic was discussed here a while back. My ancient Valoy came w/one.

Hilo · Nov 27, 2018

Ah, okay - you are probably talking about a white diffusing glass that sits on top of the condenser? Send us a picture of it, just to make sure !

dickgillberg · Nov 27, 2018

Thank you all, I'll try to send a picture soon.

dickgillberg · Nov 28, 2018

I took some pictures. Sorry for crap old Iphone pictures.

summicron1 · Nov 28, 2018

The first image shows the anti-newton ring thing over the bottom of the condenser. The second and third look to be some sort of ground diffusion glass over the top of the condenser ... it won't hurt anything. It is there to soften the light going through to minimize scratches on the negatives ... i have a Minox enlarger that has a very dense diffuser that does the same thing.

You could probably remove it unless scratches on your negs are a problem. In addition to minimizing scratches it probably reduces definition a titch...the head of a focomat is designed to diffuse the light a bit already, so this seems to me to be overkill.

Hilo · Nov 28, 2018

Difficult to see what exactly is on top of your condenser. Can you take that glass on top of the condenser out of there and take a picture of it?

At one point you will have to take out the condenser to clean it. When you do first take away the AN glass, otherwise it falls off when you bring the condenser up !

dickgillberg · Nov 29, 2018

Thanks.
When I looked at it it's very slightly frosted on one side so it make sense that it is a kind of diffuser. I'll try it out some day. The best thing is maybe that it prevent some dust on the condenser. I'll have to do a cla on the enlarger. I noticed that the helicoid need some grease, it have some kind of play.

Saganich · Nov 29, 2018

Question: How is the glass seated up there so it isn't coming in contact with the filter tray? Just for fun I tried to fit a diffuser in mine so I could use a vario cold light that was meant for a bessler. I could never get the diffuser to seat so it wasn't in contact with the filter draw.

dickgillberg · Nov 29, 2018

Saganich said:
Question: How is the glass seated up there so it isn't coming in contact with the filter tray? Just for fun I tried to fit a diffuser in mine so I could use a vario cold light that was meant for a bessler. I could never get the diffuser to seat so it wasn't in contact with the filter draw.

It sits just under the bajonett mount of the condenser. It is a round piece of glass the fits over the spring.

Saganich · Nov 29, 2018

Ahhh. Over the top of spring below the filter draw. Thanks.

Hilo · Nov 30, 2018

dickgillberg said:
Thanks.
When I looked at it it's very slightly frosted on one side so it make sense that it is a kind of diffuser. I'll try it out some day. The best thing is maybe that it prevent some dust on the condenser. I'll have to do a cla on the enlarger. I noticed that the helicoid need some grease, it have some kind of play.

It is difficult to know if this glass was Leitz made. It sounds like anti newton glass (slightly frosted) and therefore not like a diffusing glass. That would be more white. Anti Newton glass has little, if any, effect on the print. That depends on the intensity of the frosting.

I have an extra condenser that fits on to the standard Ic condenser and it comes with a white round diffusing glass that you can drop into and on this extra condenser. Made by Leitz for sure - probably to be used in combination with a point light source.

Anyway, also with the Focomats people made their own modifications and they're often interesting.

choiliefan · Nov 30, 2018

Thinking back on it, when I bought my 1C Color it came with a loose round plastic or glass disk which may serve the same function.
Will have to look for that...

glass over condenser on a focomat 1C

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