Brilliant White: safe for darkroom walls?

Jonathan R · Jan 20, 2013

This is probably just a stupid question, but I guess it's best to be sure. I'm just about to paint the walls of my new darkroom. It occurs to me that Brilliant White contains optical brighteners. As far as I understand, these are basically fluorescent materials that absorb energy at UV wavelengths and re-emit it within the visible range of wavelengths. Since amber/red safelights are at the other end of the visible spectrum, can I safely assume that these optical brighteners are 'safe' in a darkroom?

cliveh · Jan 20, 2013

Jonathan R said:
This is probably just a stupid question, but I guess it's best to be sure. I'm just about to paint the walls of my new darkroom. It occurs to me that Brilliant White contains optical brighteners. As far as I understand, these are basically fluorescent materials that absorb energy at UV wavelengths and re-emit it within the visible range of wavelengths. Since amber/red safelights are at the other end of the visible spectrum, can I safely assume that these optical brighteners are 'safe' in a darkroom?

Yes. However, quantum mechanics may not agree.

RalphLambrecht · Jan 20, 2013

white walls are perfectly fine for a darkroom. the only place where you may need black paint is around the enlarger.

cliveh · Jan 20, 2013

RalphLambrecht said:
white walls are perfectly fine for a darkroom. the only place where you may need black paint is around the enlarger.

And the light trap entrance.

Ed Bray · Jan 20, 2013

What about blue walls, would safelight hitting them be reflected as unsafe light?

cliveh · Jan 20, 2013

Ed Bray said:
What about blue walls, would safelight hitting them be reflected as unsafe light?

No and why would you want blue walls in a darkroom?

cowanw · Jan 20, 2013

They would come up as black since there would be no blue light to reflect. Red however would be a great darkroom paint, as it would reflect only safe light even if your safelight were unsafe.
Of course this is not a perfect world and few things emitting and reflecting are precisely as they seem.

Ken Nadvornick · Jan 20, 2013

The key point here is not what color the walls are, it's what color the walls reflect.

If all of the possible sources of light in a darkroom are safe (by whatever definition of "safe" is required for the process being performed), then by definition the walls—regardless of their color—cannot reflect an unsafe color. In this case any color will do. But white is preferred to spread the "safe" light around more efficiently.

The problems arise when one has white walls and the enlarger leaks imaging light. Or the doorframe leaks white light. Or the safelights aren't really totally safe. Then white walls only make the problem worse. In those cases black would be the ideal color, because you'd want to limit the spread of the "unsafe" light as much as possible.

Regarding the OP's question about UV causing optical brighteners to emit light from the walls, I've never heard of this being a problem. But the guaranteed solution would, of course, be to simply add UV light to the set of "unsafe" light colors and eliminate it from the darkroom the same as regular white light. And amber/red, not being UV, should have no practical effect.

Ken

Ed Bray · Jan 20, 2013

cliveh said:
No and why would you want blue walls in a darkroom?

Perhaps if your Darkroom were dual use, say a bathroom or bedroom with Blue Walls but occasionally used as a darkroom. Not everyone has the space for a seperate darkroom. The question was just something that occured to me.

cliveh · Jan 20, 2013

Ed Bray said:
Perhaps if your Darkroom were dual use, say a bathroom or bedroom with Blue Walls but occasionally used as a darkroom. Not everyone has the space for a seperate darkroom. The question was just something that occured to me.

A good point to which I agree.

Roger Cole · Jan 20, 2013

White is best. I painted my last darkroom white and will do so when I build out the current one. The only light present should be safe. The wall color does affect how much safelight you can use but makes it easy to bounce safelights off the walls (and ceiling.) You should test and adjust the intensity in any case. You might have to dim your safelights a bit with white walls but you'll still have more even illumination at the same level.

tkamiya · Jan 20, 2013

Also... Don't forget the ceiling!

I have white walls and white ceiling. When I burn in my prints, I can tell areas that was not supposed to gain any exposure does. My enlarger, Omega D2 leaks light horizontally and UP. Obviously, reflected lights are reaching my paper on baseboard.

I've seen some darkroom practioners create a black surround for enlarger only. That may be an option too.

Prof_Pixel · Jan 20, 2013

Roger Cole said:
White is best.

Interesting. All the darkrooms I've worked in (including many at Kodak) were painted flat black.

David Brown · Jan 20, 2013

Prof_Pixel said:
Interesting. All the darkrooms I've worked in (including many at Kodak) were painted flat black.

Me, too - as far as darkrooms that were not my own, such as in schools. I think this was the accepted wisdom in the past, especially in darkrooms where more than one person might be working.

However, the bottom line is that if the safelights are "safe", then the walls can be any color, so why not as light as possible. The exception is leaking enlargers, which is a separate problem that should be addressed.

JBrunner · Jan 20, 2013

My darkroom is red. No hi jinx.

AgX · Jan 20, 2013

White is advisable as with less means you gain an even illumination.

Comcerning reflectect exposure light bouncing back to the paper, a shielding of the paper can be applied. The most simple form would be a black painted section behind the enlarger. Alternative one could use a black roller blind. Also mobile shieldings at other sides of the enlarger. It's a question of weighing between the "trouble" of shielding versus the lighting efficiency gained by white walls.
Local black shieldings could also be used in provisional darkroom. Think of black card/foamboard too.

But what about the white shirt of the Apugger?? Thought about that?

Jonathan,
why not look for a wall-paint without optical brighteners? Are the paint buckets all sealed today? Otherwise make a check with a UV-lamp before buying.

bobwysiwyg · Jan 20, 2013

But what about the white shirt of the Apugger?? Thought about that?

Perfectly acceptable provided one is wearing a black tie.

grahamp · Jan 20, 2013

I have near-white walls. I also have white shelves, as it is a small space and there would be a lot of pockets of shadow without the reflection otherwise. I have a 'skirt' of blackout fabric around the carrier on one of my enlargers because it seems more prone to lateral light leakage and is closer to the wall than the other. On balance I think a neutral (white, or grey, or black) is better than a colour. Safelights can vary from red through orange to light brown, or green in a colour darkroom (though with my eyesight a dark green light is next to useless ). A neutral should be equally effective in all cases.

A good washable surface is a good idea.

Worker 11811 · Jan 20, 2013

The walls in my projection room are royal blue. When I had them painted, people kind of looked at me funny but, after we got the room done, people liked it.

When the lights go out for projection, they are indistinguishable from black and reflect nearly no light. When the lights are on, they don't look like a dark cavern like black paint would have.

Everybody else was pushing for black but we have a few other rooms that have black walls. It's actually difficult to work in an all-black room. There is no detail in the walls. That makes it difficult to gain perspective and determine where objects are in the room, relative to each other. Blue walls give enough detail that it's comfortable to work.

In my darkroom, the walls are wood paneling. Medium brown. I figure good enough.

tkamiya · Jan 20, 2013

I did little researching on this subject:

http://www.mufong.com.tw/Ciba/ciba_guid/optical_brighteners.pdf

It's amazing how many different products COULD contain optical brighteners, including the very product we use to make photographs ourselves. (see page 9)

I think the first step in this research should be to confirm if the paint OP plans to use indeed contain Optical Brighteners. If the answer is no, then there is no concern. If yes, if it will actually be sufficient to cause problems in photographic processes. My guess is no but without some firm data, we all be guessing.

OP is really asking not about wall color, so I'd suggest he'd start there.

My walls are pretty white. No problems in my personal darkroom. (other than reflection of light leaks from my enlargers)

MattKing · Jan 20, 2013

A lot of shared darkrooms are painted black, because it is always difficult to control what light others may spill.

I wouldn't worry a lot about brighteners that respond to UV, unless you intend to use poorly shielded, UV light emitting light sources (and if so, why?)

Nige · Jan 20, 2013

AgX said:
But what about the white shirt of the Apugger?? Thought about that?

I use a colour anaylser as an exposure meter and moving around in front of the enlarger whilst taking readings does effect it (not much but it shows up on the readings). I've never worried about it but maybe I should buy a black t-shirt for darkroom work!

Steve Smith · Jan 21, 2013

Ken Nadvornick said:
The key point here is not what color the walls are, it's what color the walls reflect.

The colour of the wall is the colour the walls reflect!

Steve.

Ken Nadvornick · Jan 21, 2013

Steve Smith said:
The colour of the wall is the colour the walls reflect!

Damn! Busted!!

I knew someone was going to catch that. Could I wiggle out of it by saying that the OP was really asking about UV-induced fluorescence? Naw, that's too far of a stretch. I'm just an idiot...

Ken

Jonathan R · Jan 21, 2013

Well I guess my original question was not an issue. Thanks.

Seem to have started a hare, though. Once in my school days I painted a darkroom flat black. Never again. It was so gloomy. I want light and lots of it, safe when that's needed, otherwise white light. Good points about enlarger leaks, though. Mine is quite well behaved, but a flat black section around it would be a good idea. This is a new build dedicated darkroom shed, so I can decorate it how I like. No bathroom ducks.

Brilliant White: safe for darkroom walls?

Jonathan R

cliveh

RalphLambrecht

cliveh

Ed Bray

cliveh

cowanw

Ken Nadvornick

Ed Bray

cliveh

Roger Cole

tkamiya

Prof_Pixel

David Brown

JBrunner

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AgX

bobwysiwyg

grahamp

Worker 11811

tkamiya

MattKing

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Nige

Steve Smith

Ken Nadvornick

Jonathan R

Brilliant White: safe for darkroom walls?

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