A Fluorescent Safelight

nworth submitted a new resource:

(there was a url link here which no longer exists) - A Fluorescent Safelight

A Fluorescent Safelight

Background:

Over the past several months there has been a lot of discussion in the forums about home built safelights using LEDs or fluorescent lamps. When I built my
new darkroom, I decided to try to build my own safelight. For many years I have used a commercial safelight that is a 24 inch standard cool white fluorescent tube inside a special sleeve that makes it the equivalent of an OC safelight. This has been an excellent lamp, and it is safe for up to...

Click to expand...

(there was a url link here which no longer exists)

Very good article, if you are doing B&W only, great.

I worked in a commercial darkroom where there were 4' fluorescent lamps in some of the darkrooms but only tungsten in the rest.

The fluorescent tubes are a bit of a problem with colour paper as they do retain a slight afterglow. In a large darkroom this is sometimes not a problem, but in a smaller darkroom, there was a problem with long exposures with colour paper.

We were actually able to see the shape of the tube (glowing slightly) about 30 seconds after we turned the lights out, as our eyes started to open up.

Another issue was with the instant startup, they sort of fizzle a bit after repeated switching over a period of about ½ a year. Especially if you are doing about 300 colour prints in a days work and there are two shifts.

Mick.

Also note that you should replace your theatrical gels regularly. They do eventually change(or wear out) over time, just like the Ilford Multigrade gels/filters.

The Rosco #27 tube filters are $14.95 each in the current (#47) Rosco catalog. My local dealer will give me a 10% discount, even though I'm ordering only two. Check their web site (http://www.rosco.com) for local dealers. He said they could be shipped direct to my home. You may also be able to order direct from Rosco, at least their customer service folks were very prompt in replying to an email.

The catalog number for 48" T12 filters made of #27 material is:

110 08401 4812 27

The sleeves come with end caps, though these might not be needed with the red fluorescent lamps.

The #27 material is called "Medium Red". It's actually much darker than your standard red filter for black-and-white photography, more like the B+W-brand 091. Given the spectral transmission curve (in the little swatch book the dealer gave me, and at the Rosco site), I'll try some standard 48" tubes with the filters first. There's nothing to lose but 30 minutes and a few sheets of paper for testing, and it could wind up being much less expensive than the minimum order of 6 F40T12/R tubes.