The Light of the World

[Michael Hiles]

Advertisement (gone after registration)

I would like to increase the brightness of the light in my Focomat 1c. I am currently using a 212 (150w) bulb. My exposures can become very long – up to 3 minutes at f5.6 for a max autofocus enlargement (9.3 x 14).

 

Any practical suggestions that don’t involve bad smells and require an inspection from the fire department?

[M.Hilo]

Hi Michael,

 

Good to hear you are always printing !

 

I don't understand why you have such long exposures. My 20X24 (50X60) prints can go to 90 seconds, but not 3 minutes. Sorry for this question, but do you keep the top glass of your condenser clean? Sometimes a hardly visible layer of fine dust sits there . . .

 

Otherwise, I do use a 250 watt bulb now and then. Just make sure you do not take too long setting up. Or first use your 150 bulb for setting up, then switch to the 250 watt.

 

Which version Focotar do you have? They're expensive but the Focotar-2 is okay to use wide open. You could also consider getting a 50mm that opens at 2.8 and use it one stop closed. The Computar is very good at that.

 

Best,

 

Michael

[pico]

I would like to increase the brightness of the light in my Focomat 1c. I am currently using a 212 (150w) bulb. My exposures can become very long – up to 3 minutes at f5.6 for a max autofocus enlargement (9.3 x 14).

 

Any practical suggestions that don’t involve bad smells and require an inspection from the fire department?

 

Michael, I am surprised by your long exposures with 150w bulb! Let's approach a solution first. I will leave my questions to last.

 

I used a Valoy, now in storage, which I think has the same light house dimensions as the 1c. My model was set up for particularly great enlargements and to allow hot bulbs it used a 'bonnet' between the lamp housing and condenser stage. This bonnet vented the heat of a hot bulb while keeping it all light-proof. I have used 240w bulbs in it. I Below are pictures of the cooling head bonnet.

 

187mm diameter for the part that fits the lamp housing. ~190mm for the fit over the condenser stage.

 

Looking down from the bulb side:

 

 

Looking up from the condenser:

 

 

OH! My question regarding such long exposures - are you using an unusual technique with dense negatives?

 

Very Best,

Pico

 

PS: Yes the paint/coating is worn. I am off to clean and repaint it in real flat-black.

[Michael Hiles]

Thanks Michael and Pico,

 

I will check cleanliness and dust. The lamp house has not been looked at in many years (although the Ic lives under a plastic shroud.

 

The focotar is about 1970 or so. It came with the enlarger, which I bought new way back then. I have no reason to question it - the prints are fine, very sharp, no problems whatever. I tend to use max f5.6, and going to f4.5 would not make a huge difference in exposure time.

 

My negatives are almost all XP1 or now XP2, exposed for 200 ASA. There are some much older negatives on Panatomic-X, but very rarely are they “thick”. And if I have a disaster of a negative, it is unlikely to be printed.

 

I believe that the later Valoy and Focomat have the same optical and light system at least from the condenser up. Since I don’t leave the light on for long periods, likely a 240/250 watt bulb would not cause serious heat problems. Now to find one.

 

I think I also need to look into the small details like accumulated dust. So many thanks. I’ll let you know re: progress.

[M.Hilo]

Michael,

 

Back in the eighties I taught photography. A student had inherited a 1c from her father and she came to class with very soft prints and complaining the exposures were long. I went to see the enlarger, also inside the lamp head, all looked okay. Until I dragged my two fingers over the condenser: there appeared what looked like a highway on a glass globe.

 

To clean the condenser take it out by turning the black bayonet ring, remove the spring and the AN glass at the bottom of the condenser. Using two fingers of each hand you can then lift it out. Warm water and soap for the dishes plus a soft sponge, rinse well and dry with a soft cloth . . .

 

Your story makes me wonder if an opal bulb can lose its capacity gradually? When did you last change it? Or, did you change it recently? Have you double checked it's not a 75watt? Perhaps the manufacterer made a mistake.

 

Pico, looks to me that the worn paint coat of your bonnet would not give any bad light effects. I would think twice about painting that unless you are sure the new paint can deal with the high temperatures. Anyway, it is a wonderful solution and I should really find it. But first I must check the diameter size. The Valoy II, Focomat Ic and IIc are all the same and I change heads between them. However, I don't know if their diameter size is the same as the early Valoy (non-II). Thanks for already giving the size !

[Michael Hiles]

Thanks Michael,

 

I dismantled and removed the condenser as you advised. It was a little dusty – not touched in very many years. The enlarger has lived under a plastic tent all its life. I cleaned the condenser (both sides and the anti-Newton’s rings glass) and the reflector surface in the upper part of the housing, and we will see. Whether there was (lets say) 1 stop worth of dust is not clear – I will see what happens next time I print.

 

The bulb is probably 5-7 years old – but the total running time was likely 5 hours running time max. I like printing but I don’t print very often. Maybe I should buy a new bulb (and a spare for safety), and perhaps a 240/250-watt unit (a 213?). I don’t leave the power on unnecessarily, so even a stronger bulb would not likely get very hot.

 

I appreciate all the help. This is a great community.

[M.Hilo]

Advertisement (gone after registration)

Here you go Michael, the 213 around the corner: http://www.ebay.com/itm/PH213-PH-213-250W-120V-Opal-Enlarging-and-Photoflood-Lamp-/380885239821?hash=item58ae87880d:g:kE8AAOSw0vBUk1xB

 

They surely have the 150 watt opal bulbs

[pico]

Pico, looks to me that the worn paint coat of your bonnet would not give any bad light effects. I would think twice about painting that unless you are sure the new paint can deal with the high temperatures. Anyway, it is a wonderful solution and I should really find it. But first I must check the diameter size. The Valoy II, Focomat Ic and IIc are all the same and I change heads between them. However, I don't know if their diameter size is the same as the early Valoy (non-II). Thanks for already giving the size !

 

My paint is good for flatness and heat. I bake the parts after painting. No smoke.

 

I just re-read your post. I tried my ventilator hood on my Focomat IIa. It is too small in diameter. I do not know if the IIa and IIc have the same size housing.

[Michael Hiles]

Here you go Michael, the 213 around the corner: http://www.ebay.com/itm/PH213-PH-213-250W-120V-Opal-Enlarging-and-Photoflood-Lamp-/380885239821?hash=item58ae87880d:g:kE8AAOSw0vBUk1xB

 

They surely have the 150 watt opal bulbs

 

Thanks Michael - they are in Toronto which is easy - no borders or customs.

[Guest]

I am not surprised by the long times. For my dense negs I easily hit the 2mins realm at f8 and 5x7" on the V35 (which is about 1 stop dimmer than a 1c with 75 W opal lamp). With the same setup a normal neg takes 4 seconds (2 seconds on the Ic). Unless you have normal or thin neg, there's probably nothing wrong with your apparatus.

 

Try the 250W bulb. There are 500W bulbs as well. The Ic is not rated for that high a wattage. But for short times, it might be tolerable. Dr. Fischer makes those 500W bulbs:

 

http://www.dr-fischer-group.com/de/produkte/speziallampenfabrik-dr-fischer-gmbh/?pa=pro&ca=All&pd=432

 

I think they also do have even higher wattages opal bulbs (for greenhouse application I believe it was). With those high wattages generating a lot of heat it might be sensibel to have a second upper half of the head with the high wattage only used for exposing the paper and a lower wattage one for setting up.

 

Kienzle Phototechnik makes high wattage heads as well (using halogen bulbs I believe).

 

Tungsten bulbs don't change properties significantly with time and or use (except for the first time you use them, when wolfram gets hot the first time it becomes much more brittle and shock sensitive). Other than that they put out constant light levels over their lifetime. CCFL do get dimmer with use, so do LEDs (a lot).

 

 

Andi

[Michael Hiles]

Thanks Andi.

 

I think I will start by ordering a 250 watt PH 213 and seeing how it goes. 500 watts or 2 lamp housings seems like a stretch at this point. And I certainly won't risk frying anything. The 250 watt solution sounds reasonable. The light is never on for extended periods (adjustments are minimal with autofocus), and I am not doing volume production, so I am expecting no heat problems with a little care.

 

However it turns out, if the exposures remain longish, it is unlikely to ruin civilization as we know it.

 

Many thanks for your note.