What's the deal with red dark room lamps?

One summer, I volunteered at a Veterinary Hospital near my home. One of my shared duties, besides giving angry chihuahuas baths and cleaning up litter boxes, was to develop the x-ray film. I was always careful to keep the x-ray film closed in its light-proof box before entering the dark room and turning on the dark room lamp. I’ve been told that dark room lamps are red because that certain wavelength of red light doesn’t have enough energy to expose film. And sure enough, I looked up the photoelectric effect in a Chemistry book, and there was a photo of a guy in a dark room. This got me to thinking, how do they take pictures of the interior of a dark room if the only source of light is the red dark room lamp, and that lamp’s light isn’t supposed to be of high enough frequency to expose photographic film?

Just a WAG…but they probably don’t use an actual darkroom light…it’s doubtful this photo was a spontanious snapshot, rather than a staged event, so getting a regular red light that will expose the film well wouldn’t ruin any work in progress.

Well, for one thing, they use color film. From what I’ve been told, red is only used to light darkrooms for black and white film. Color film has to be developed in pitch-black darkrooms. Presumably, the x-ray film you were working with was black and white film, judging by every x-ray picture I’ve ever seen.

I don’t know about x-ray film or paper, but generally, black and white photo paper can be exposed to dim red light and be OK, color photo paper needs to be in total darkness. No type of film can be exposed to any kind of light, and some can’t be exposed to heat, either.

a few corrections-

that red (and sometimes yellow) darkroom light will, in fact, expose film. When one manually processes a roll of film, they must do so in a pitch-black room. Truly a nerve-wracking procedure, by the way; i took a b&w photography class last summer, and let me tell you, there is nothing more stressing than having to open a roll of film with a can opener, pulling the film out without touching the film except for the edges, snipping off the front and end pieces, and loading it onto a metal spool. Good god damn, friends. I remember on several occasions having fallen down to my knees in there, almost in tears and covered in sweat, praying to god that i could load the film without any of the film touching. Annnyways, the darkroom light won’t expose photo paper onto which one makes one’s prints. Therefore, when it comes to taking photos of a darkroom, im sure that if one used incredibly fast color film, they would be alright.


Right, the conversation I was remembering was about making prints from negatives, not about developing the film itself. And there’s also film that will show infrared light as well.

I’m just thinking how much the darkroom people would be pissed if you forgot to turn the flash off when taking a picture of their darkroom.

When it comes to photographs the red light went out with Ortho film (which went out at the early part of this century). Ortho couldn’t see red.
Look at a photo of Teddy Roosevelt or the women marching for suffrage. The red stripes in the US flag will photograph black. Later black and white photos using panchromatic film will show the stripes as a dark gray.

H.P.E. this was very funny: “…let me tell you, there is nothing more stressing than having to open a roll of film with a can opener, pulling the film out without touching the film except for the edges, snipping off the front and end pieces, and loading it onto a metal spool.”

I learned to process film at summer camp and I think they were afraid to leave a bunch of us in a dark room with a “leader” so we had lightproof dark boxes (made of cloth with hand holes and cuffs and other sorted light barriers) about 12"x12"x12" - we sat around a dimly lit room, sweating madly, each figuring we’d lose fingers and have the bloodiest, scratched film in camp.


Doug, Ortho film did not die at the turn of the century. Maybe it died for conventional snapshot-type photography, but it’s been alive and kicking in the printing industry for five decades or more.

Virtually all the negatives used to make (“burn”) printing plates are on extremely high-contrast ortho film. In fact the stuff is commonly call “lith film,” as in lithography (aka offset printing) film; Kodak’s version is called Kodalith film.

Um, couldn’t you use night vision goggles in a dark room?


Of course, they could have just turned the regular light on to take the photo. There often IS a normal, every day lightbulb somewhere in a dark room. In fact, I’ve experimented with a process called “silverization” which dicates that after exposing the photosensitive paper and sliding it into the developer you flash the regular old lightbulb on for a split second. Makes a GREAT effect on black and white photos in which the whitest tones are replaced by silver. Way cool. There was a bare bulb over the developer pan for this reason.

It’s not that the darkroom can’t HAVE a real light, just that it can’t be on during certain stages in film processing.


On the Sunday before finals week in the semester when I took my first photography class in college, I had to go into the photo lab and develop my backlog of B&W film. Unfortunately, on that day I also had the worst hangover I’ve ever had in my life. Never mind getting the film loaded onto the spool; I was afraid that I’d pass out in that little pitch-black closet and no one would find me until Monday, or God knows when. But I made it through the day, and I even passed the class!

I’ll second the previous info about ortho film still being used in printing. There are also dupe and reverse film, which can be used “out in the open” as long as the overhead lights have amber filters; there can be white light nearby, but not too close, and you don’t want to leave unprocessed film out very long.

I miss cutting rubylith!

The above mentioned technique is also called “solarization,” or more properly, the Sabbatier effect.
Photoshop has a filter that approximates this really difficult-to-control effect. It’s a fun little trick, and Man Ray used it in some of his work.

HP - keep practicing! Trust me, rolling film becomes an absolute cinch after a while. It helps a 1000000 if the metal reels you use have not been bumped around too much and warped. Also, although incredibly fast film may work to take the photo, chances are that someone used a slower speed film and a tripod. And, as Tengu said, most likely it was a set-up. Incidentally, exposure metering for red light is a pain in the ass. Most camera meters will be fooled by it and underexpose.

B/W film is panchromatic (sensitive to almost all visible color frequencies.) B/W paper is not sensitive in the red/orange part of the spectrum. This is one reason that color negs printed on standard black and white paper look a little off in contrast. The paper is not sensitive to all color in the spectrum. You need to use a special color to black and white print paper that Kodak sells which is sensitive to red/orange to get the best results from printing color negs on b/w paper.

X-ray film is a significantly different entity. The X-ray film we use in our lab (Kodak X-OMAT AR) can, in fact, be exposed to light down to about 600 nm wavelength without being exposed in the least. The reactions we use to expose the film emit at about 400 nm, well low enough to expose the film. The film is then developed, but we never put it onto any sort of paper; we just use the film, a negative image as it were.

Most laboratories never use anything but the negative image.


Yes! That’s it! I knew it didn’t sound quite right. Silverazation? Where did I come up with that. Thanks for putting that tip-of-my-tongue thing back where it belonged :slight_smile:

WAG: The night vision goggles work by absorbing light, and since in dark rooms there is no light, there isn’t anything for the night vision goggles to absorb.

Most night vision goggles simply amplify the existing light, as you said. I have no idea whether there would be enough light in a darkroom to use those. Some night vision goggles use infrared light, which is given off by anything warm. They would at least be useful for seeing where your hands are.

Oh cool so I was kinda right…