How dark should a darkroom be?

fschifano said:

Ah, but there's the rub. There could be just enough exposure to stray light to rob the prints of contrast, but not enough to cause obvious fog. In other words, the paper could be exposed to just under the threshold where it becomes visible. Since exposure is cumulative, when you expose the print you drive the fog level past the threshold.

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That's exactly right!

it might be but for right now it's what I have. can't put a door up there as there is nothing to mount a door up, can't use screws to put up a perma curtain. and the room does double duty for other things so don't want to go with the ol' tape method as that will become a pain very quickly.

so far it seems to be working up to my satisfaction though as right now I'm not going after the perfectionist look or anything just more working on getting what the hell I'm doing down as best as I can and getting negatives developed correctly is my first and formost issue as I can't seem to get a good dense set of negatives out.

how much of a difference are we really talking about here though as far as loss of contrast?

rx7speed said:

i

how much of a difference are we really talking about here though as far as loss of contrast?

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For some people, none. For me, everything. I put a lot of work, heart, and energy into a print. I refuse to be harpooned by things I can control.

You may be fine though. Test. It's literally that simple. One sheet and ten minutes. A no-brainer, and 100% more effective than speculation.

Ken Nadvornick said:

How dark?

Mind-numbing, sensory-depravation, terror-inducing, unimaginable to contemplate, insanity-creating, you should fear for your very survival, as if you unexpectedly awoke inside your grave with proof there is no God... dark.

It either is, or is not. There is no try...

Ken

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Wise words from Master Yoda.

Around this time last week I was at the bottom end of a long subterranean cave in Western Australia. After turning off my headlamp and sitting in the cool silent dark for a few minutes, I had a new appreciation of just how dark a perfect darkroom would be. The sort of dark you can sit in forever and still see nothing at all. Slightly creepy actually...

Ian

RalphLambrecht said:

I was in Howard Bond's darkroom once, and he has no darkroom door at all. The whole entrance is designed as a light trap. You walk around a double corner in which the walls are painted flat black. It is open and yet light tight, which is great for a teaching darkroom where people can go in and out without disturbing the session. It takes some floor space but is very convenient and offers a lot of ventilation.

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The Evergreen State University (Olympia, Washington) has a great darkroom with about a dozen enlargers in use all the time... and no door. They do hang a black felt curtain in an entrance configured almost exactly as Bond's entrance is described. I suspec the curtain is overkill but perhaps not.

Light does not bend around corners unless by reflection or an appropriate shaped lens. Painting the entrance flat black largely supresses reflection but not entirely. Perhaps this is why the university uses the black curtain.

No greenie jokes allowed I assume. In any event, I am just amazed that a school whose school mascot is a Geoduck and whose motto is something that translates to something like “let it all hang out” has a darkroom. I am impressed and just have to say go Geoducks! I doubt that the U-dub has a dark room anymore.

In reading all the responses, its seems no one is complaining that there is anything wrong with Black being black, just that it is hard to do for some. My interpretation, which may be different from others, is that for some, they just cannot make it black, for whatever reason. For others, they don’t think it’s really needed and are unaware of it being any problem, but have not tested.
I have tested my safelights years ago but not to the extent that is now recomened, although I plan to test them again.
I have always accepted that if the darkroom is black and I cannot see any light no matter how long I wait, I have total darkness, or real black. Do those who know, as I do that total black is the standard, do I need to further test, to confirm what my eyes cannot see after extended times?

fotch said:

In reading all the responses, its seems no one is complaining that there is anything wrong with Black being black, just that it is hard to do for some. My interpretation, which may be different from others, is that for some, they just cannot make it black, for whatever reason. For others, they don’t think it’s really needed and are unaware of it being any problem, but have not tested.
I have tested my safelights years ago but not to the extent that is now recomened, although I plan to test them again.
I have always accepted that if the darkroom is black and I cannot see any light no matter how long I wait, I have total darkness, or real black. Do those who know, as I do that total black is the standard, do I need to further test, to confirm what my eyes cannot see after extended times?

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In regard for your safe-lights being safe for the paper you are using, yes. It isn't that hard, when I bring a new paper into the darkroom, I simply run a test at the beginning of a printing session. A very brief flash with the enlarger sans neg, and than 6 minutes with an opaque object on the paper, then process and fix. If there is no outline from the object, I'm good to go. The preflash method is a better test than just setting out a paper with something on it and looking for an outline on white.

It either is, or is not. There is no try...

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That might make you feel all fuzzy and satisfied, but the issue is not nearly as straightforward as that, anyway. Do you have chilled microbolometers with 1-photon sensitivity to ensure absolute darkness? Do you even know how much darkness is "dark enough" to be safe for your film, even if you did? Most people measure the darkness of a darkroom by how dark it "looks" in there. That's only a very rough measurement. You have to use both your eyes and your brain when determining appropriate light-tightness.

The fundamental error in reasoning here is that if it's black to your eyes, it's black to the film. But that's a very simplistic criteria. You can actually develop film by inspection by shining enough light on it that you can see it with your eyes, but the film is unaffected. So much for visible=bad. You can easily see a lit candle from across a completely dark basketball court, but there is no way that candle would effect your film. Your eyes have lenses to focus the light from the candle onto a spot on your retina, and maybe if you had the film in a camera with a lens to focus the candle's light into a spot on the film in would register. But with the film out in the breeze that candle is so far away as to be irrelevant, even though you can easily see it. A similar situation exist in darkrooms with minor leaks, glow-in-the-dark timer dials, etc which might be easily visible to your eyes but completely irrelevant to your film. On the flip side, even if you can't see any light at all, I guarantee you there is some in there floating around. Most BW films are UV sensitive, and if you are using IR film it could be completely dark in there and you could still have fogged film. So the eye=film criteria fails on both ends....it could appear completely black to you, and yet still be unsafe for your film. And YOU could be able to see light sources that are completely harmless to your film. I can tell you that a few minor light leaks around your door or a boldly glowing GraLab timer dial a few feet away may very well be completely safe. One day I had been bulk-loading film in the dark for hours and eventually my eyes adjusted to where I could see my feet because of light leaking in the bottom of my door. So here I am standing, loading film in canisters, and I can look down and see the pattern on my socks, which would have been completely black a half hour ago before my eyes got REALLY adjusted. I had been loading film like that for a long time. I didn't fix the leak. I still load film in there.

All that matters is that it is dark enough to not effect the film significantly during the amount of exposure the film is likely to have to the room. That's what matters. Not whether or not you can see it. If being able to see or not was relevant, you might as well just close your eyes all the time.

They eye test is invalid. The way to be really sure is to test...and do a proper test with pre-and-post flashing. I have adjustable safelights that I turn up until they fail the test, and they ALWAYS fail a proper pre/postflash test much much sooner than they will fail a naive "coin" test. What this means is that your print highlights and contrast might be being effected by your safelight even if you can leave the paper out for 10 minutes and still develop it to white.

BetterSense said:

Do you have chilled microbolometers with 1-photon sensitivity to ensure absolute darkness?

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Umm... it was a tongue-in-cheek paraphrased quote from a Star Wars movie. That's why I included a ' '. Just trying to "lighten" things up a bit in this discussion. Perhaps you missed the part above that about waking up "inside your grave with proof there is no God...?"

But since you broach the subject, yes... I think darkness (defined as the absence of light) can be considered a mutually-exclusive, binary state - as Yoda was paraphrased. Either there is at least one single stray photon, in which case you would be standing in a (very, very) DIMroom. Or there is not, in which case you would be standing in a DARKroom. At least as regards those particular photons that are of concern to your particular light-sensitive materials.

The degree of DIMness thus required is therefore left as an exercise for the reader, each standing in their respective rooms, and with their respective light-sensitive materials out in the open and in harm's way.

Ken