New bulb for focomat 1c

75 will give 30 sec at 8x with F8.

150 makes a lot of heat. Ok to use a 150 and put dimmer in circuit for small prints.

Best to use an enlarging meter to get the center and edges the same exposure ( up and down) and then swing around to get all the corners the same. Will be perfect if you do it right.
 
Thank you for the answers. I might get one of each to test it out. It is almost 20 years since I did some prints in a darkroom. Does anyone know a place to buy bulbs? I live in Sweden.
 
I just got two new 150w bulbs from a old shop near from where I live. Yes!

I've not tested them out yet on a print, but when I installed them in my focomat I noticed that the enlarger head get warm very quickly. I've heard that some put the multigrade filter on top of the condenser. Is there a risk for the filter to melt?

I should mention that the focomat is new to me.
 
150w is pretty hot...
You would have to test..but the filters on the condenser works fine generally.
If you want..you can also adapt a small color head or B&W multi contrast head to replace the top half of the Focomat head and have an even more convenient solution than popping filters in and out...
 
There are Focomat Ic enlargers out there with a filter drawer. These are very convenient.

When your filters cannot stand the heat of the lamp, it is better to use a 75w bulb. I used for many years a Valoy II enlarger (the same as a Focomat Ic, but without autofocus) with a 75w bulb. To change the filter, I had to lift up the top half of the lamp house. The filters were placed on top of the condenser.

Erik.
 
It depends on the speed of the paper you're using and the length of exposure you like to use. For example some Foma papers are extremely slow and Berger is much faster as is Ilford multigrade warmtone. Hard to answer without answering these questions.

I personally like around a 30 second exposure so whatever it takes to get that with the lens at f8 for a specific paper and magnification.

I tried a half dozen bulbs and couldn't find one that gave even illumination. No matter where I put the height illumination was different at various places. I measured it with a Minolta incident meter.

I use multigrade paper and putting filters under the lens was always a pain. I wound up adapting an Omega 2-1/4 dichroic head to it and now the illumination is perfect across the field at f8 and all I have to do is dial in my contrast filters now.
 
The evenness of the illumination is very important when using hard grade paper. When the negatives are dense and soft grade paper is used, this is less important.

Bulbs often (always) give an uneven illumination. The Leitz enlargers anticipate on this. You can turn the lamp until the illumination is at its best. A given fact is that the central part of the image that the enlarger delivers is more luminous than the borders, but the central part of negatives is usually more dense than the borders (when standard or wideangle lenses are used), so this unevenness is automatically compensated. It helps too when the enlarging lens is used on f/11 instead of the usual f/8.

Erik.
 
If you need more light and less heat, you can always give standard E27 LED bulbs a try, preferably 4000K for VC paper. Whether this works depends a bit on the setup of your condenser system. So far I have fitted two enlargers (Meopta Magnifax and Durst L138) with LED bulbs and the conversion worked better than expected.
Of course the standard bulb variety with white globe (not the filament type clear/frosted) should be used. The best angle of illumination (neither too wide nor too narrow) will depend on the design of your lighting system and may need some practical testing. A 15 watt 4000K LED bulb gives a lot of light (my exposure times halved compared to a 150 Watt opal lamp) and the heat is negligible. This is really a big plus when going large or working with dense negatives.
 
Resurrecting this thread to ask about exposure time on my newly acquired 1c. I purchased a 75-watt bulb and am doing small, 5x7 postcards. The exposure times are 4-5 seconds. Does this sound right? I'd prefer a bit longer to have more control.

Any thoughts appreciated! Thank you!
 
I don't have this enlarger but seems like a short exposure time...where is the aperture set on your lens??
I prefer the 10-15 sec. range and depending on which lens I'm using I'm at f/11...
I don't do any dodging or burning...the longer the exposure you have, the easier you can fine tune your final print.
 
twvancamp said:
Resurrecting this thread to ask about exposure time on my newly acquired 1c. I purchased a 75-watt bulb and am doing small, 5x7 postcards. The exposure times are 4-5 seconds. Does this sound right? I'd prefer a bit longer to have more control.

Any thoughts appreciated! Thank you!
Click to expand...

You didn't say what aperture you were using, but that sounds about right. You can of course stop down. Going past f/11 will start to hurt your sharpness. Sharpness will depend on what lens you have as well. You didn't tell us that either.....

If you want to slow it down, you can lay a 67mm neutral density filter on top of the condenser. That is what I do with mine. You don't need a fancy one either. Any cheap one will work fine.

Hope that helps you.
 
Thank you for the replies.. This was at f11 as I’d not like to go past that. Using the original Focotar 50mm.

I will look into the density filter but appreciate any other thoughts!
 
I ordered a cheapie condenser filter, but also saw in another thread that you could raise the bulb.

I was able to raise mine ~1.5". I haven't had a chance to test yet but I think this will help a bit at least.
 
twvancamp said:
I ordered a cheapie condenser filter, but also saw in another thread that you could raise the bulb.

I was able to raise mine ~1.5". I haven't had a chance to test yet but I think this will help a bit at least.
Click to expand...

I think the height adjustment of the bulb is for adjusting the evenness of illumination. Bulbs vary in size so that adjustment might be needed; I do tend to switch between bulbs without readjusting though.

I use vc filters in mine by just laying them inside. That increases exposure time too.
 
The Focotars are process lenses..and can be used wide open or 1/2 stop down for max sharpness..this comes from Ralph Gibson.
Dont know why you would want to degrade the image at f11..
You could also plop a small color head on it and have longer exposure times.
 
Yes I certainly don’t want to use it at 11, but any larger and the times will be a blink. I will experiment this week with the raised bulb and some filters.
 
You must log in or register to reply here.
Back
Top