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WATTS - Hot light, Cold Light
Briefly: For strictly black & white printing, does a cold head gives as
much _usable_ light as, say, four 150W tungsten bulbs? Four 250W bulbs? Do the cold lights give more effective light per-watt? You see, I was given that might (might) be suitable for a light head for the Saltzman 8x10" enlarger. Maybe. It is steel, uses four Edison base bulbs with wiring sufficient to accommodate four 250W bulbs. It has four 150 bulbs now. (GE brand with the printing on the side of the bulbs.) The bulbs are on the sides of the box, in reflectors and shielded from direct view of the negative carrier. And there are two fans in it and it's light proof vented, and it has a large, thick, heatproof glass over the open part. I do not think it was ever an enlarging head. For good reason, I'll bet. (If it is important I can make a snapshot to post to my web site.) Thank you, all. -- JJS in MinneSnowta |
#2
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WATTS - Hot light, Cold Light
"John J" wrote in message m... Briefly: For strictly black & white printing, does a cold head gives as much _usable_ light as, say, four 150W tungsten bulbs? Four 250W bulbs? Do the cold lights give more effective light per-watt? You see, I was given that might (might) be suitable for a light head for the Saltzman 8x10" enlarger. Maybe. It is steel, uses four Edison base bulbs with wiring sufficient to accommodate four 250W bulbs. It has four 150 bulbs now. (GE brand with the printing on the side of the bulbs.) The bulbs are on the sides of the box, in reflectors and shielded from direct view of the negative carrier. And there are two fans in it and it's light proof vented, and it has a large, thick, heatproof glass over the open part. I do not think it was ever an enlarging head. For good reason, I'll bet. (If it is important I can make a snapshot to post to my web site.) Thank you, all. -- JJS in MinneSnowta I'm not sure what you have but it might have been an illuminator of some sort. There were lamphouses along those lines used on enlargers. In general flourescent lamps, including the compact type, produce quite a bit more light per watt than incandescent lamps. I don't think there is a definite ratio but I would say about four times the light. For use on an enlarger using variable contrast paper the phosphor color needs to be selected so that the filters will work. Normal "cold light" enlarger lamps were pretty blue and require a yellow filter to get any sort of range and then its compressed. I think the warm-white compact lamps that look like tungsten may work pretty well but you will have to try them and the filters will probably not have quite the same contrast or spacing that they do with a tungsten lamp. The compact flourescents will dissipate a fraction of the heat of a tungsten lamp with similar light output. You can get compact lamps with light output equal to at least a 200 watt tungsten lamp at many stores but I don't know if they come in all colors. For graded paper the blue lamps work fine. -- -- Richard Knoppow Los Angeles, CA, USA |
#3
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WATTS - Hot light, Cold Light
If you have a range of contrast grades to print, incandescent are the
best choice IMOP. Cold light is fine if your negatives fall within the normal to more contrasty range. Most papers are spectrally suited and formulated to work better with incandescent. In article , John J wrote: Briefly: For strictly black & white printing, does a cold head gives as much _usable_ light as, say, four 150W tungsten bulbs? Four 250W bulbs? Do the cold lights give more effective light per-watt? You see, I was given that might (might) be suitable for a light head for the Saltzman 8x10" enlarger. Maybe. It is steel, uses four Edison base bulbs with wiring sufficient to accommodate four 250W bulbs. It has four 150 bulbs now. (GE brand with the printing on the side of the bulbs.) The bulbs are on the sides of the box, in reflectors and shielded from direct view of the negative carrier. And there are two fans in it and it's light proof vented, and it has a large, thick, heatproof glass over the open part. I do not think it was ever an enlarging head. For good reason, I'll bet. (If it is important I can make a snapshot to post to my web site.) Thank you, all. -- JJS in MinneSnowta -- Reality is a picture perfected and never looking back. |
#4
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WATTS - Hot light, Cold Light
Richard Knoppow wrote:
"John J" wrote in message m... Briefly: For strictly black & white printing, does a cold head gives as much _usable_ light as, say, four 150W tungsten bulbs? Four 250W bulbs? Do the cold lights give more effective light per-watt? You see, I was given that might (might) be suitable for a light head for the Saltzman 8x10" enlarger. Maybe. It is steel, uses four Edison base bulbs with wiring sufficient to accommodate four 250W bulbs. It has four 150 bulbs now. (GE brand with the printing on the side of the bulbs.) The bulbs are on the sides of the box, in reflectors and shielded from direct view of the negative carrier. And there are two fans in it and it's light proof vented, and it has a large, thick, heatproof glass over the open part. I do not think it was ever an enlarging head. For good reason, I'll bet. (If it is important I can make a snapshot to post to my web site.) Thank you, all. -- JJS in MinneSnowta I'm not sure what you have but it might have been an illuminator of some sort. There were lamphouses along those lines used on enlargers. In general flourescent lamps, including the compact type, produce quite a bit more light per watt than incandescent lamps. I don't think there is a definite ratio but I would say about four times the light. For use on an enlarger using variable contrast paper the phosphor color needs to be selected so that the filters will work. Normal "cold light" enlarger lamps were pretty blue and require a yellow filter to get any sort of range and then its compressed. I think the warm-white compact lamps that look like tungsten may work pretty well but you will have to try them and the filters will probably not have quite the same contrast or spacing that they do with a tungsten lamp. The compact flourescents will dissipate a fraction of the heat of a tungsten lamp with similar light output. You can get compact lamps with light output equal to at least a 200 watt tungsten lamp at many stores but I don't know if they come in all colors. For graded paper the blue lamps work fine. Thanks, Richard. I think you are talking about the bulbs available to replace ordinary tungsten Edison based bulbs. If that's the case, then I will go to the home supply place today and get a couple and first try them in the Focomat Ia! What better way to test without spending a lot? If the bulbs are not suitable, I'll put them in the workshop. Rise-time concerns me, but I'll find out! JJS |
#5
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WATTS - Hot light, Cold Light
____ wrote:
If you have a range of contrast grades to print, incandescent are the best choice IMOP. Cold light is fine if your negatives fall within the normal to more contrasty range. Most papers are spectrally suited and formulated to work better with incandescent. Oh. Darn. I must confess that in forty years I have never chosen subjects to suit a processing regime. I'm not Zone obsessive. All I use is a simple N-+ exposure and development method. It would be different if I were a studio photographer. So having an ideal negative is really unlikely for me. Said without disrespect to Zone Masters. JJS |
#6
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WATTS - Hot light, Cold Light
"John J" wrote in message m... Richard Knoppow wrote: "John J" wrote in message m... Briefly: For strictly black & white printing, does a cold head gives as much _usable_ light as, say, four 150W tungsten bulbs? Four 250W bulbs? Do the cold lights give more effective light per-watt? You see, I was given that might (might) be suitable for a light head for the Saltzman 8x10" enlarger. Maybe. It is steel, uses four Edison base bulbs with wiring sufficient to accommodate four 250W bulbs. It has four 150 bulbs now. (GE brand with the printing on the side of the bulbs.) The bulbs are on the sides of the box, in reflectors and shielded from direct view of the negative carrier. And there are two fans in it and it's light proof vented, and it has a large, thick, heatproof glass over the open part. I do not think it was ever an enlarging head. For good reason, I'll bet. (If it is important I can make a snapshot to post to my web site.) Thank you, all. -- JJS in MinneSnowta I'm not sure what you have but it might have been an illuminator of some sort. There were lamphouses along those lines used on enlargers. In general flourescent lamps, including the compact type, produce quite a bit more light per watt than incandescent lamps. I don't think there is a definite ratio but I would say about four times the light. For use on an enlarger using variable contrast paper the phosphor color needs to be selected so that the filters will work. Normal "cold light" enlarger lamps were pretty blue and require a yellow filter to get any sort of range and then its compressed. I think the warm-white compact lamps that look like tungsten may work pretty well but you will have to try them and the filters will probably not have quite the same contrast or spacing that they do with a tungsten lamp. The compact flourescents will dissipate a fraction of the heat of a tungsten lamp with similar light output. You can get compact lamps with light output equal to at least a 200 watt tungsten lamp at many stores but I don't know if they come in all colors. For graded paper the blue lamps work fine. Thanks, Richard. I think you are talking about the bulbs available to replace ordinary tungsten Edison based bulbs. If that's the case, then I will go to the home supply place today and get a couple and first try them in the Focomat Ia! What better way to test without spending a lot? If the bulbs are not suitable, I'll put them in the workshop. Rise-time concerns me, but I'll find out! JJS One problem with any gaseous discharge lamp, which includes all fluorescent lamps, is that the output varies with temperature. The lamps like to run hot and in an enlarger should preferably be run continuously. The original lamp house used in the Saltzman employed mercury vapor tubular lamps which were run continuously so that exposure was controlled by a shutter similar to the Packard shutter which was held in front of the lens on a fixture. A shutter also give precise control of exposure, large tungsten lamps have a lag on turning on and take a short time to fade out. Not a problem for the small wattage lamps found in most enlargers. The compact fluorescent lamps are cheap enough to allow testing plus if they don't work you can use them around the house. -- -- Richard Knoppow Los Angeles, CA, USA |
#7
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WATTS - Hot light, Cold Light
Richard Knoppow wrote:
One problem with any gaseous discharge lamp, which includes all fluorescent lamps, is that the output varies with temperature. The lamps like to run hot and in an enlarger should preferably be run continuously. The original lamp house used in the Saltzman employed mercury vapor tubular lamps which were run continuously so that exposure was controlled by a shutter similar to the Packard shutter which was held in front of the lens on a fixture. A shutter also give precise control of exposure, large tungsten lamps have a lag on turning on and take a short time to fade out. Not a problem for the small wattage lamps found in most enlargers. The compact fluorescent lamps are cheap enough to allow testing plus if they don't work you can use them around the house. Excellent points. We discussed the lens shutter earlier. I had modified an electric long-roll camera shutter to use on the Saltzman, but learned that it was not proper to use with my favorite timer, the F-Stop timer from Darkroom Automation. The essential issue there was that the electric shutter was really intended for faster shutter speeds than needed with enlarging. There were components to close it, a capacitor, and other things. Don't need that here. I have plenty of experience with Packards. I use one for very large lenses. For some reason I thoughtlessly disregarded the Packard solution for enlarging. It will work perfectly with the F-Stop and any other conventional timer. I'll actuate the Packard electrically with a simple, low-overhead DC electric piston or solenoid. I've done the later. Happy day. It is about to rain so I'll spend the afternoon with a spare Packard and the Saltzman head. Thank you, Richard JJS |
#8
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WATTS - Hot light, Cold Light
John J wrote:
Briefly: For strictly black & white printing, does a cold head gives as much _usable_ light as, say, four 150W tungsten bulbs? Four 250W bulbs? Do the cold lights give more effective light per-watt? You see, I was given that might (might) be suitable for a light head for the Saltzman 8x10" enlarger. Maybe. It is steel, uses four Edison base bulbs with wiring sufficient to accommodate four 250W bulbs. It has four 150 bulbs now. (GE brand with the printing on the side of the bulbs.) The bulbs are on the sides of the box, in reflectors and shielded from direct view of the negative carrier. And there are two fans in it and it's light proof vented, and it has a large, thick, heatproof glass over the open part. I do not think it was ever an enlarging head. For good reason, I'll bet. (If it is important I can make a snapshot to post to my web site.) Thank you, all. -- JJS in MinneSnowta John, my .02, for my enlargers (yet to be completed, due to lack of anywhere to put them) I'm making a cold light head, basically 10-15mm neon tube, bent in a serpentine manner, quite a bit larger than need be, 2 pieces of thin white acrylic and I will have a light source that won't buckle negatives, and should give me decent exposure times. Basically a Aristo head, Voltarc, the company that makes Aristo, happens to be a supplier to the neon industry as well (no surprise, huh? Properly processed neon tubes are bright as all get out, and using a Packard type shutter(from a graphic arts camera, with a 110v solenoid)I can leave the tubes on continuously, heck, maybe I'll add a few resistors in the cabinet to keep the lamp house at a constant temperature as well. erie |
#9
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WATTS - Hot light, Cold Light
erie patsellis wrote:
John, my .02, for my enlargers (yet to be completed, due to lack of anywhere to put them) I'm making a cold light head, basically 10-15mm neon tube, bent in a serpentine manner, quite a bit larger than need be, 2 pieces of thin white acrylic and I will have a light source that won't buckle negatives, and should give me decent exposure times. Basically a Aristo head, Voltarc, the company that makes Aristo, happens to be a supplier to the neon industry as well (no surprise, huh? There is still the issue of the Kelvin temp of the light. No? Properly processed neon tubes are bright as all get out, and using a Packard type shutter(from a graphic arts camera, with a 110v solenoid)I can leave the tubes on continuously, heck, maybe I'll add a few resistors in the cabinet to keep the lamp house at a constant temperature as well. Fer gosh sake, Erie, let's set up a studio and darkroom somewhere between here and there, or maybe here. I am close to retirement. Closer than I want to be. |
#10
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WATTS - Hot light, Cold Light
John J wrote:
erie patsellis wrote: John, my .02, for my enlargers (yet to be completed, due to lack of anywhere to put them) I'm making a cold light head, basically 10-15mm neon tube, bent in a serpentine manner, quite a bit larger than need be, 2 pieces of thin white acrylic and I will have a light source that won't buckle negatives, and should give me decent exposure times. Basically a Aristo head, Voltarc, the company that makes Aristo, happens to be a supplier to the neon industry as well (no surprise, huh? There is still the issue of the Kelvin temp of the light. No? Yes, and there are several neon tubes that get us in the 3000 to 3200 degree range, you can also go with 2 tubes, one more towards the blue spectrum, one towards the green, for those multigrade types. Properly processed neon tubes are bright as all get out, and using a Packard type shutter(from a graphic arts camera, with a 110v solenoid)I can leave the tubes on continuously, heck, maybe I'll add a few resistors in the cabinet to keep the lamp house at a constant temperature as well. Fer gosh sake, Erie, let's set up a studio and darkroom somewhere between here and there, or maybe here. I am close to retirement. Closer than I want to be. If only the school had a good FA program, I might be tempted, the wife graduates this year, and we were planning on moving to St. Louis, unless I find a better program that will accept an old fart set in his ways, and just looking for "artistic" guidance, instead of attempting to teach me aperture, shutter speeds, here's how you develop b&w film, etc... fer chrissake, I probably process more b&w & C41 film in any month than most college labs do in a year. |
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