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light bulb for darkroom

Janet Cull - Western NC , Dec 24, 2002; 09:06 a.m.

Pardon if this is double posted. I asked this last night, but can't find it in a forum so suppose it went into space.

Will the 11 watt amber bulb (under 3 bucks!) I saw at Lowe's suffice in my darkroom. I'll be printing b&w, nothing unusual as far as papers or films. Some say, "yes". Others say it has to be a special type of amber bulb. Anyone know for sure? Thanks.


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Al Kaplan - Miami, FL , Dec 24, 2002; 09:15 a.m.

Film, NO! Paper, maybe. Take a sheet out of the box in total darkness, or with a known safe safelight, turn on your amber bulb for about 10 minutes, and then process the paper. Put a few coins on the paper while it's sitting out. Even if the safelight is almost safe you'll see the coin shadows when you develop it.

B&W film can stand a few seconds to a VERY dim green light for "developing by inspection".

Robert Davis , Dec 24, 2002; 09:24 a.m.

$3 US isn't much less then what the local photo stores sells little red safe lights.

Edward Zimmermann , Dec 24, 2002; 09:53 a.m.

I don't know what "Lowe's" is (beyond the U.S. stateside entertainment group) but if its just an amber coloured party bulb I'd re-think your investment. $3 USD does not get you many sheets of photographic paper--- many of my papers cost more than that for a single sheet--- but a $3 USD party bulb can in the blick of a eye fog them all. Party bulbs are meant to glow a specific colour but without penalty for not being 100%.... That old American phrase comes to mind "Penny wise and Dollar foolish". This is really an area where a lot of care and even more testing needs to be done. Many older safelights too may have aged in less than desirable ways so you need to continue testing on a periodic basis to confirm that things today are still safe.. Fog can be quite subtile and effect the shadows and contrast..

David Goldfarb , Dec 24, 2002; 09:55 a.m.

Get a Bright Lab bulb, which is a big globe-type bulb that screws into an ordinary lamp socket. It puts out a good amount of safe light for printing (not for film, of course), lasts about 5 years depending on how much printing you do, and is fairly inexpensive. If you can't find one locally, you can order them from bhphoto.com.

Lex Jenkins , Dec 24, 2002; 09:56 a.m.

Definitely...maybe. You're better off getting a darkroom-rated bulb, or better yet, a darkroom rated fixture, from a camera shop or other source.

The only way to know for certain whether a bulb or fixture with filter is truly safe is to test it on some strips of printing paper. Cover half the paper (some folks set coins on the strips), expose the paper for 3-30 minutes (depending on your patience and how much time you expect your paper to be exposed under normal usage), develop and fix and inspect for evidence of fogging. Any part of the paper that was covered will be lighter, assuming the lamp is not darkroom safe.

No darkroom lamp or bulb should be closer to your paper than 3-5 feet, preferably a bit farther away - including for the fogging test. Any darkroom light can induce fogging if close enough to the paper.

The bulb will eventually burn out. If you get a fixture - a lamp housing with an internal socket and an external filter (usually amber, sometimes red or green), you can use any ordinary low wattage bulb. I use a fluorescent bulb shaped light an incandescent bulb inside my "beehive" (thanks to Pete Andrews for that term) fixture with standard "OC" (amber) filter. The beehive faces upward and distributes reflected light from the ceiling so I use a slightly higher watt bulb than normal. In effect, the brightest light source is on the 10-foot ceiling, well away from the paper.

Also, my the overhead heater in my bathroom/darkroom which glows red is also darkroom-safe. It doesn't provide much light, tho', but at least I can leave the heater on while I'm working.

None of this applies to film. To be safe film must always be handled in the dark. (There's an exception, ortho film, which can be handled under a particular type and wattage of light, but let's just say no light for safety.)

Once the film is in the developing tank and capped, ordinary room light is fine again. Anything you read about developing in total darkness, using a film-safe light, etc., is old news from the days when sheet film was processed in open tanks.

Ake H Olsson , Dec 24, 2002; 10:14 a.m.

I have used the special bulbs before. They generally work fine - especially when new - but in my experience they have a problem with aging. Tiny cracks in the "paint" will appear and white light will leak out.

Currently I prefer a safelight with a thick plasticky filter casing that has a regular small 25w bulb inside it. Also when the bulb burns out it is fairly cheap to replace.

Price for the "painted" bulb is c. $20 whereas the other type can be had from $27 and upwards.

Jim Rock , Dec 24, 2002; 10:50 a.m.

Spend the $20 to $25 on a safelight unit. If money is a problem, you can find one on eBay, including shipping, for under $10. Don't ruin a lot of paper and time (plus chemicals) trying to save a couple of bucks.

John Stockdale , Dec 25, 2002; 04:10 p.m.

the safelight test needs to be done on a sheet of paper *already* exposed to a light grey. If you do it on completely unexposed paper you will get a false sense of security and probably affected prints. Have a look at Kodaks document about safelights testing. It's really worth doing a proper test.

Edward Zimmermann , Dec 26, 2002; 03:08 a.m.

"the safelight test needs to be done on a sheet of paper *already* exposed to a light grey..... Have a look at Kodaks document about safelights testing. It's really worth doing a proper test."

I'd also extend the test, given the nature of amateur darkrooms in contrast to the functioning of a professional lab, to reflect possible movements in the room, for example, closer to the lights. If, for example, you pass on your way to the development trays, resp. drums or slots, better lit (as usual) positions these should be choosen as well for testing. Even though paper once in the developer is hardly sensitive to light I still like to check the safe times at that position (without, of course, developer or other fluids). You want to be able to move freely around the darkroom for minutes with a piece of paper and have no fear of the slightest of fogging.

The goal is: The brightest room lighting possible that's safe for all your papers"

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