Quick safe light question re bromide paper

Last year a friend gave me a considerable stash of old (1970s) mostly Kodak bromide paper. In December I made a few successful test prints from one box so it's likely all still quite usable.

Am I right in thinking that these papers need a green safe light and not the more common red? I tried with my red safe light and observed fogging, whereas a green light from my phone resulted in less fogging. I just want to be sure before i purchase another safe light.

I had a lot of Kodak Bromide paper, just needs a standard red or orange safe-light or an OC/902 (amber) variable contrast safe-light.

Ian

Agulliver said:

Am I right in thinking that these papers need a green safe light and not the more common red?

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No, that makes no sense. Apart from (today, no longer manufactured) panchromatic papers, no papers are sensitive to red light. Red sensitivity is something an emulsion needs to be sensitized for specifically and there has never been a need for this in printing from B&W negatives. Hence, a red safelight is always a good choice. This is under the condition that the safelight is truly red, and not also emits light in other parts of the spectrum. Red leds are often problematic in this sense as they tend to have secondary emission peaks in the green part of the spectrum, which necessitates additional filtering.

But an old-fashioned fixed grade paper that works OK under a yellow safelight will also work OK under a red safelight.

If you observed fogging with your red safelight, it's either due to the paper and its age itself, or it's due to the light not being pure red.

koraks said:

If you observed fogging with your red safelight, it's either due to the paper and its age itself, or it's due to the light not being pure red.

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Or it is due to the red safelight being too bright for the paper.

MattKing said:

Or it is due to the red safelight being too bright for the paper.

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No matter how bright it is, as long as it's outside the band where the paper is sensitive, it's just not going to fog it. I have insanely bright safelights in my darkroom...

One might ask what your red safelight actually is. In working with "green sensitive" X-ray film (Fuji HR-T) I have found problems using an LED red bulb unless I cut the brightness down with some filtration AND add a Rubylith (red) filter. In the land of solid state magic, things are not always as one expects.

koraks said:

No matter how bright it is, as long as it's outside the band where the paper is sensitive, it's just not going to fog it. I have insanely bright safelights in my darkroom...

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True, but red safelights vary in how narrow their red light spectrum is, and some papers have sensitivity that is very low but not zero around the red part of the spectrum.
I have red LED safelights that pass the full Kodak safelight test at 3-4 feet away from the paper, but don't pass that test when closer.

Absolutely, my experience echoes that if @DWThomas in that leds require additional filtering with rubylith. There's almost always a secondary emission peak smack in the middle of the green part that needs to be taken care of.

I agree with MattKing. When coating my orthochromatic plates, I have to be careful about exposure to my red (as in, 650nm LEDs behind #2 safelight filter) safelights... too bright they fog up. Too long (10+ minutes) they fog up. Took a long time to figure out why I was getting seemingly unpredictable base fog. Now that’s all straightened out.

“practically no response to red” is not the same as zero response.

My red safelight is a pretty old one. I don't have it to hand right now but it's a well known photographic brand.
I also don't have the bromide paper boxes to hand (lockdown, they're in storage) but some of the boxes stated to use a green safe light hence my question. All interesting, I'll stick with the red.

Agulliver said:

I also don't have the bromide paper boxes to hand (lockdown, they're in storage) but some of the boxes stated to use a green safe light hence my question..

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It does seem strange that the paper's maker should state that a green light should be used, given it flies in the face of all that has been said. When you do get the boxes out again it will be interesting to know exactly what the contest of the statement was. It might be that memory plays tricks in that a green safelight was mentioned but not quite in the way your memory has recalled it

pentaxuser

Sounds like something panchromatic, like Panalure, rather than a standard B&W paper.

I'd surely tend to follow the box recommendation; if the box calls for a green safelight, it likely also specifies a very puny wattage and considerable distance form enlarger easel and trays, and as noted above, that's probably because that box is a special panchromatic material.

I have a momentary contact footswitch (rubberized, waterproof) on the floor below the sink connected to my orange safelight. It's never fogged any b&w paper. I never leave it on. Even luminous timer hands or LED's on darkroom equip controls can fog certain things if what's in the sink "sees" them.