"Never mix OC and red safelights in the darkroom"

BetterSense · Sep 29, 2009

Never mix OC and red safelights in the darkroom -- even if a paper can be used with either safelight, the combination will usually cause fogging.

This is from freestylephoto.

I recently discovered how much better amber safelighting is than red safelighting. It's a lot more comfortable, and it seems to be fine with my paper. I saw this quote from freestylephoto's safelight page and it doesn't make any sense to me. I'm not sure why you would use both red and amber at the same time, but I don't see why a blend of them would be worse than either one by itself, if the total output was the same.

RalphLambrecht · Sep 29, 2009

The freestylephoto quote is ... well, the technical term is 'wrong'. You are right, it makes no sense.

Interestingly enough, I recently switched to dark red lights from amber. I got used to the different lighting now. I needed it, because at the time, I tested a few East-European papers, which required a red safelight. I also tested it with my Ilford papers, and the red safelight is a lot 'safer', which just means that I can handle it for more than 32 minutes without any fogging.

BetterSense · Sep 29, 2009

I'm going to build both LEDs onto my heatsink with individual brightness knobs, so that I can just turn up the red instead of orange if I need to. I've been using a red Cree led and it's worked very well so far. An amber LED should be fine.

I would just use my orange filtered safelight but I would rather have less heat in my small dark-closet.

bdial · Sep 29, 2009

I use both, started off with OC then went to red for the Eastern European papers, like Ralph. But I've not ditched the OC, I just don't turn it on when I'm working with papers that require red.
If a paper is safe under red and safe under OC, I too don't see how a combination could be less safe, unless the total illumination is too much. In my experience the combination is fine.

BetterSense · Sep 29, 2009

Which papers are un-OC safe? Right now I use some Illford, Arista Private Reserve and Arista.edu ultra. I checked the Illford and Adox datasheets, but it might be good to know in the future.

MattKing · Sep 29, 2009

It may be that if you use both red and amber, it may be more difficult to determine if the total level of safelight illumination is too high.

Matt

fschifano · Sep 29, 2009

Fotokemika Varycon papers require a red safelight according to their web site. Don't bother trying to load the pdf files unless you read what I think is Croatian. Arista.EDU Ultra papers are rebadged Foma papers and are supposed to be safe under OC safelights, but the tech sheets for Foma papers suggest red is better.

Rick A · Sep 29, 2009

I've only ever used red safelights. I mainly use Eastern European papers, and they all recommend red. I dont see any problems with the light on Kodak or Ilford papers.
Rick

fschifano · Sep 29, 2009

...and you never will, provided of course that your red safelight is truly safe. If OC or amber safelights work, then red will surely work and probably afford a safer environment for the paper. The downside to red safelighting is that it is harder to see by. Amber or OC saflighting is easier on the eye, but not necessarily on the paper.

RalphLambrecht · Sep 29, 2009

fschifano said:
...and you never will, provided of course that your red safelight is truly safe. If OC or amber safelights work, then red will surely work and probably afford a safer environment for the paper. The downside to red safelighting is that it is harder to see by. Amber or OC saflighting is easier on the eye, but not necessarily on the paper.

Careful Frank, I agree with your statement, but red ain't necessarily red. There is red (#1), light red (#1a) and dark red (#2). I use a dim #1 filtration for paper. #1a has a high transmittance between 620 and 700 nm (higher than light amber 'OC'), and #2 is too dark for human vision.

Anon Ymous · Sep 29, 2009

fschifano said:
...Amber or OC saflighting is easier on the eye, but not necessarily on the paper.

And yellow green must be even better, but certainly not for any paper. I've got darkroom lamps, red and yellow green. The later can be very good with some papers, provided that their are put far enough. I tested them at 1,5m away and 2 minutes is the maximum with Ilford MGIV. At 5-6m away, they are harmless. I tested with Foma, but 10 seconds exposure from 1,5 gave light grey...

BetterSense · Sep 29, 2009

The Amber LED has a pretty sharp output at 590nm. The Fomabrom datasheet above suggests this should be OK even with foma, but I will test anyway.

Rick A · Sep 29, 2009

I guess I've been in the darkroom for so many years now, that I could probably work in total darkness and not know the difference.
Rick

fschifano · Sep 29, 2009

You're right of course Ralph, but for paper the red 1A is fine. It's the one I use in the darkroom and by the standard fogging test (flash a piece of paper, put a coin on it, let it sit under a safelight for several minutes, then develop the paper), it proved out to be more safe than the OC safelights I'd been using. The darker ones should be even safer, but then what good is it if you can't see what you're doing?

RalphLambrecht · Sep 29, 2009

fschifano said:
You're right of course Ralph, but for paper the red 1A is fine. It's the one I use in the darkroom and by the standard fogging test (flash a piece of paper, put a coin on it, let it sit under a safelight for several minutes, then develop the paper), it proved out to be more safe than the OC safelights I'd been using. The darker ones should be even safer, but then what good is it if you can't see what you're doing?

Frank

It depends on the intensity of light. I have six 15W safelights in my darkroom and need to have them VERY dim!

Anscojohn · Sep 29, 2009

BetterSense said:
The Amber LED has a pretty sharp output at 590nm. The Fomabrom datasheet above suggests this should be OK even with foma, but I will test anyway.

**********
I'm intriqued by the LED technology, but not so much as to spring for the EK. Are there any cheap really workable alternatives that don't require special power sources?.

Lee L · Sep 29, 2009

Standard base 120VAC LED bulbs:

Dead Link Removed US$3.95 red or amber
Dead Link Removed US$7.95 red or amber

Others from the same and from other vendors. Easy to find with a simple google search. Superbrightleds has been an excellent vendor in my experience, with low prices, quick shipping, and reasonable shipping charges.

Lee

michaelbsc · Sep 29, 2009

RalphLambrecht said:
Careful Frank, I agree with your statement, but red ain't necessarily red. There is red (#1), light red (#1a) and dark red (#2). I use a dim #1 filtration for paper. #1a has a high transmittance between 620 and 700 nm (higher than light amber 'OC'), and #2 is too dark for human vision.

Ralph, are you saying that the #1 filter is preferred?

I just bought some cheap 5x7 lights on evilbay with no name plastic OC filters, and I'm scrounging for some good red filters. If I should avoid 1a I would like to know.

As an aside, it occurred to me that I can put a very small compact fluorescent bulb instead of the recommended 25W incandescent as a heat controlling mechanism. I know the CF bulbs cannot safely be used as white light in the room as they have an afterglow that will fog film and paper. Is that afterglow UV, and will the #1 filter trap that making them safe?

Has anyone tried the red CF party lights as safelights?

MB

BetterSense · Sep 29, 2009

I'm pretty sure a colored filter will absorb the UV from a CFL. My current amber safelight has an overly-bright CFL in it and it's still safe.

Anscojohn · Sep 29, 2009

Lee L said:
Standard base 120VAC LED bulbs:

Dead Link Removed US$3.95 red or amber
Dead Link Removed US$7.95 red or amber

Others from the same and from other vendors. Easy to find with a simple google search. Superbrightleds has been an excellent vendor in my experience, with low prices, quick shipping, and reasonable shipping charges.

Lee

Thanks. Do you think the amber would be safe with VC papers?

Jerevan · Sep 30, 2009

As the Foma papers have been mentioned in the thread, does anyone know what sort of filters work with Fomabrom? I am using a LPL SG4 (should be close to Kodak #2) but would like something a little less dim. I tried to contact Foma directly but they don't answer at all.

Anon Ymous · Sep 30, 2009

Jerevan, you didn't specify if you're talking about Fomabrom (graded) or Fomabrom Variant (VC). In any case, you can see the spectral sensitivity of any of their papers, and compare it with the absorbency chart of your filters.

Jerevan · Sep 30, 2009

Sorry, I was thinking about Fomabrom VC. I see that the pdf has been updated with more information since I last read it. It seems I read an outdated version which didn't say anything about the 610 nm wavelength. I am not sure how to interpret the information, though. Does that mean that anything with a wave length from 610 and under would work? If so, I guess my Encapsulite R10 (with a wavelength of 610 nm) would be safe?

Anon Ymous · Sep 30, 2009

This paper has it's maximum spectral sensitivity at 550nm and drops to zero at about 575. Any filter that doesn't leak light with wavelengths between 550 and 575 would therefore be safe. Anything from 580nm and over sounds fine, the 610nm filter should be ok, provided that it's sharp enough. In any case, the distance between the paper and the safelight is something to consider. When you double the distance, the maximum allowed time doesn't double, it gets 4x.

Jerevan · Sep 30, 2009

Thanks a lot, Anon! I have never really figured out those spectral charts. I'll do a test and see if there's any fogging. Eventually I think I am going to get a LED light source.

"Never mix OC and red safelights in the darkroom"

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