Focomat IIc replacement bulb and exposure times

Jack Baty · Dec 4, 2022

I thought I'd gotten the correct replacement bulb for my IIc but exposure times are very short. Making an 8x10 print of an average-density 120 negative at f11 demands exposure time of 5-10 seconds, which sure feels short.

The bulb I bought, per someone's recommendation, was the PH140 75W (photo attached). Is there a more appropriate replacement bulb? Hopefully, one that allows for longer exposure times.

Thank you.

Jack

rcphoto · Dec 4, 2022

What bulb came out of it?

Jack Baty · Dec 4, 2022

rcphoto said:
What bulb came out of it?

Fair question! I wish I remembered. For some reason, I didn't save it or any information about it. It was a "full size" bulb, quite old, but I don't know anything more.

rcphoto · Dec 4, 2022

I did a little poking, looks like some recommend a 150w bulb. I would say if you are getting times to short for you, you should be able to just use a dimmer bulb.

logan2z · Dec 4, 2022

I had a similar problem with my Beseler 23CII - replaced the bulb with the correct bulb but was getting short times. I ended up simply using an ND filter above the negative stage in order to lengthen exposure times. Not sure if that's an option with the Focomat, however.

Maris · Dec 4, 2022

Jack Baty said:
I thought I'd gotten the correct replacement bulb for my IIc but exposure times are very short. Making an 8x10 print of an average-density 120 negative at f11 demands exposure time of 5-10 seconds, which sure feels short.

The bulb I bought, per someone's recommendation, was the PH140 75W (photo attached). Is there a more appropriate replacement bulb? Hopefully, one that allows for longer exposure times.

Thank you.

Jack

Those exposure times seem completely routine for me over thousands of 120 negatives over decades of darkroom work. The thing is an 8x10 enlargement off roll film is not a big enlargement and the light doesn't get spread out very far. Local exposure control through burning and dodging is easy for me at those "short" exposure times because I have an enlarger timer with a foot switch. The foot switch leaves both hands instantly free to modify the enlarger light beam.

rcphoto · Dec 4, 2022

Maris said:
Those exposure times seem completely routine for me over thousands of 120 negatives over decades of darkroom work. The thing is an 8x10 enlargement off roll film is not a big enlargement and the light doesn't get spread out very far. Local exposure control through burning and dodging is easy for me at those "short" exposure times because I have an enlarger timer with a foot switch. The foot switch leaves both hands instantly free to modify the enlarger light beam.

This is a good point.

Jack Baty · Dec 4, 2022

Maris said:
Those exposure times seem completely routine for me over thousands of 120 negatives over decades of darkroom work. The thing is an 8x10 enlargement off roll film is not a big enlargement and the light doesn't get spread out very far. Local exposure control through burning and dodging is easy for me at those "short" exposure times because I have an enlarger timer with a foot switch. The foot switch leaves both hands instantly free to modify the enlarger light beam.

I was thinking that might be part of it. Maybe I'll just run with it this way for a bit and see how it goes. May look into an ND filter option if it's a problem.

Thanks

Hilo · Dec 5, 2022

I assume you use the normal IIc lamp head?

I use the IIc as well. My work prints are 24x30cm which gives an image size a bit smaller than A4. Large prints are up to 50x60cm (20x24in.)

I always use the traditional 150 watt bulb, like this: "enlarger bulb PH212 150w". For 75 w bulbs, I believe this is 211.

With 24x30cm prints my exposure times start at about 15 seconds and can be over 20 seconds. I use the Focotars 100mm f5.6 or the 60mm f4.5. Always closing 2 stops.

I assume you close the lens two stops? If so, the only difference between the traditional enlarger bulbs and the one you use is their shape. Perhaps the shape of yours results in more light. If I were you I'd get some regular bulbs, 75w and 150w.

Like these: https://www.bhphotovideo.com/c/prod...am_11657p_ph211_lamp_75w_115_125v_6_pack.html

Finally, 120 film tends to have shorter exposures than 135mm. The above is mostly about 135mm film. Doing 24x30cm prints of 120 negatives, it happens I close the lens 3 times . . .

Philippe-Georges · Dec 5, 2022

I had the same 'problem' with my OMEGA D3 B&W enlarger. Printing from 6x6 cm negatives on 24x24 cm format (Fomabrom FB 111 'multigrade') gave me exposure times of around 6 to 10 sec., at F8 (the ideal F for Rodagon), with a 75W bulb.
These short exposure times made me nervous, particularly when dodging...

So I am using ND filters now, 0.3 and 0.6 and even both on top of the variabel condenser, to lengten the exposure time so I can burn and doge more easily and precisely.

I don't think photo paper suffers from reciprocity...

koraks · Dec 5, 2022

Jack Baty said:
Making an 8x10 print of an average-density 120 negative at f11 demands exposure time of 5-10 seconds, which sure feels short.

If you use warmtone paper, you'll find that the required exposure will shift to 15 - 30 seconds or thereabouts, depending a bit on the specific paper used.

Btw, for straight prints (no burning & dodging) I routinely expose for just a few seconds; typically 3 seconds or so for small work prints.

Hilo · Dec 5, 2022

koraks said:
If you use warmtone paper, you'll find that the required exposure will shift to 15 - 30 seconds or thereabouts, depending a bit on the specific paper used.

Btw, for straight prints (no burning & dodging) I routinely expose for just a few seconds; typically 3 seconds or so for small work prints.

I did not know that! Because, since the switch from graded to multigrade paper, I have only used Ilford Warmtone.

koraks · Dec 5, 2022

Then your exposures on regular multigrade would be even shorter

Jack Baty · Dec 5, 2022

Thanks, everyone. It's comforting to hear that my times are not unusual. I only do very simple dodging/burning so I bet I can manage the shorter times.

ooze · Dec 5, 2022

I regularly stop down my focotar 100mm to f16 or even f22, with no discernible ill effects on 24x30 paper. That should give you a more comfortable range. I also use a 75W bulb and my equivalent exposure time is similar to yours.

Loren Sattler · Dec 6, 2022

I have a Focotar 1C with a standard bulb which is way too bright for modern papers. I installed a rheostat (dimmer switch) in the line between the bulb and timer and dial in an illumination that gives me 10-20 second exposure times at f5.6 (two stops down from wide open) for the enlarger lens. This works very well. ND filters would be better if I had a filter drawer but I use Ilford plastic filters below the lens. I do not want to mess with a filter stack below the lens.

eli griggs · Dec 7, 2022

Try 1000bulbs.com for searching a replacement enlarger, safelight, projector or hot light bulb.

I've had good luck over the years finding all four types there (as I recall) and they have a huge reference index of devices which are needed by Photographers.

Buy more than one when you can, they might no be there when you need your next change, and do no let your skin/skin oils touch any part of the bulb.

Cheers

Philippe-Georges · Dec 7, 2022

Try Dr Fischer, they are specialised in making incandescence bulbs for photo applications.

Philippe-Georges · Dec 7, 2022

Loren Sattler said:
I have a Focotar 1C with a standard bulb which is way too bright for modern papers. I installed a rheostat (dimmer switch) in the line between the bulb and timer and dial in an illumination that gives me 10-20 second exposure times at f5.6 (two stops down from wide open) for the enlarger lens. This works very well. ND filters would be better if I had a filter drawer but I use Ilford plastic filters below the lens. I do not want to mess with a filter stack below the lens.

That rheostat trick seems interesting, but doesn't change the lamp's colour, which interacts with the variable contrast filtering?
BTW, you can always put the ND filter on top of the negative carrier, or perhaps on top of the condenser (an leave it there)...

koraks · Dec 7, 2022

Philippe-Georges said:
That rheostat trick seems interesting, but doesn't change the lamp's colour, which interacts with the variable contrast filtering?

Yes. For b&w work and with the dinner set to the same value always it won't be all that much of a problem, most likely. Worst case you'll lose some contrast at the higher grades.

Btw, rheostats aren't used as dimmers these days. They're phase control dimmers usually, at least for incandescent bulbs. Other lighting systems use different dimming principles. I.e. don't install a phase control dimmer on a cold light or LED light, as it'll usually not work.

Philippe-Georges · Dec 7, 2022

koraks said:
Btw, rheostats aren't used as dimmers these days. They're phase control dimmers usually, at least for incandescent bulbs. Other lighting systems use different dimming principles. I.e. don't install a phase control dimmer on a cold light or LED light, as it'll usually not work.

Yes, I know that about LED light, diodes work, amongst other items like pn, on frequency and they change alternating current in to direct current.
I haven't LED lights in my enlargers.
I use LED's for tabletop work, for which these are very good...

the making of

koraks · Dec 7, 2022

Very nice, @Philippe-Georges ! Yes, LEDs have great potential in studio lighting as well as many other applications. Fortunately they generally come with dimmer circuitry already built in for most applications where this is actually relevant, so we don't have to worry about it.

My remark was based on the practice of replacing enlarger bulbs with household LED bulbs, which some people do (and often with surprisingly good results). In these cases, adding a phase control dimmer generally won't work unless the LED bulb is specified for use with a dimmer.

drfoxmd · Dec 10, 2022

koraks said:
Very nice, @Philippe-Georges ! Yes, LEDs have great potential in studio lighting as well as many other applications. Fortunately they generally come with dimmer circuitry already built in for most applications where this is actually relevant, so we don't have to worry about it.

My remark was based on the practice of replacing enlarger bulbs with household LED bulbs, which some people do (and often with surprisingly good results). In these cases, adding a phase control dimmer generally won't work unless the LED bulb is specified for use with a dimmer.

What are the advantages to using a cold light?

eli griggs · Dec 10, 2022

koraks said:
Very nice, @Philippe-Georges ! Yes, LEDs have great potential in studio lighting as well as many other applications. Fortunately they generally come with dimmer circuitry already built in for most applications where this is actually relevant, so we don't have to worry about it.

My remark was based on the practice of replacing enlarger bulbs with household LED bulbs, which some people do (and often with surprisingly good results). In these cases, adding a phase control dimmer generally won't work unless the LED bulb is specified for use with a dimmer.

My Omega E, 5" x 7" enlarge has an "Omegalite" light head, which used old GE "Circline" bulbs and I have to wonder if a new led 6000k circle light would give to d results, including with VC filters?

I do have a Omega 5"x 7" colour head with power supply, but I need to have the circuits run down and replace what is keeping it from working for me, for now

eli griggs · Dec 11, 2022

One thing I need to ask, is does the Focomat IIc use short or tall bulbs?

My Valloy II uses short enlargers incandescent bulbs, something I learned while seeking my first bulbs, which turns out to be important and can result in too short printing times.

Focomat IIc replacement bulb and exposure times

Jack Baty

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