Why do enlarger timers turn the safelight off during exposure?

BetterSense · May 3, 2009

I have a gralab timer and it turns off the safelight during exposure. I always wondered about this, because it makes it hard to align the easel since when the image is on, the rest of the room is dark and vice versa. I was considering bringing in a small auxiliary safelight just so that I could see to position the easel with the image on, but why not just plug my safelight directly into the wall and leave it on all the time? I went to the darkroom at the university and they had whole-room safelights that obviously don't turn off during exposure. What's the rationale for the enlarger timer behavior?

Konical · May 3, 2009

Good Evening, BetterSense,

I don't really know why this is the common arrangement, but perhaps it's because the less light hitting the paper the better. Safelights aren't always completely safe, so it makes sense to have paper exposed to them as little as possible.

Question: Why would you want to align the easel during the exposure? Standard practice is hands off at that time to avoid even inadvertent movement.

Konical

Andrew4x5 · May 3, 2009

Such a feature is typically required if you use an enlarging meter. Most enlarging meters are sensitive to safe lights.

BetterSense · May 3, 2009

Well, not during exposure, but you must have the enlarger on to align the easel to the image. Especially if you are cropping in the easel, this can be quite a fiddly process. I usually put a blank sheet of paper in the easel for focusing and alignment, but with the safelights off with the enlarger on it's hard to see the black blades of my easel. I usually end up turning the enlarger on and off rapidly using the persistence of vision so I can see the easel and images alternately but it makes more sense to me to just leave the safelight on. My exposures are usually less than 30 seconds and the paper is in the developer tray under safelight longer than that, so I don't see the point.

I have a homemade enlarging meter but since I calibrate it every time it would seem that the safelight wouldn't effect it any.

Ray Rogers · May 3, 2009

BetterSense said:
Well, not during exposure, but you must have the enlarger on to align the easel to the image. Especially if you are cropping in the easel, this can be quite a fiddly process. I usually put a blank sheet of paper in the easel for focusing and alignment, but with the safelights off with the enlarger on it's hard to see the black blades of my easel....

I have a homemade enlarging meter but since I calibrate it every time it would seem that the safelight wouldn't effect it any.

Are you opening the lens all the way up?
I have no problem with seeing the image on the white easel and the borders cut off by the black blades... but some lenses have smaller aps.

I thought the graylab had a toggle switch that you threw one way for normal use and the otherway for the safelight... its been many years but that is the way I remember it....

Hows the homemade meter?

panastasia · May 3, 2009

Burning and dodging is easier with the safe light off. You can always plug the safe light into another outlet.

Pinholemaster · May 3, 2009

You don't have to plug into the timer so the safelight turns off. Personally I find burning and dodging easier without the safelight on. In the school were I teach, we use sodium safelights, which take forever to come up to their brightness, so you don't want to turn them on and off constantly. We have them plug in independent of the timers used.

David A. Goldfarb · May 3, 2009

Enlarging timers are usually designed to turn the safelight off for focusing, and I suppose that turning the safelight off during the exposure is just a byproduct of that arrangement.

Christopher Walrath · May 3, 2009

But, and I noticed this last week and I have a Gra Lab as well, the safelight WILL NOT come on unless the timer was just on and has just run out to 0, as in after exposure of the paper. If you turn on the enlarger to compose another print you lose the safelight for placing paper on the easel until after the timer has run out.

So I bypassed this deficiency (IMHO) by, as aforementionedly mentioned aforely (wow, where did that come from), plugging the safelight into another outlet, not into the side of the timer.

fschifano · May 3, 2009

I use an enlarging meter, the Jobo Comparator II to be exact. It is sensitive to the safelight, so you don't want the safelight on while making measurements. I also find it much easier to compose and focus with the safe lights off. I use a blank sheet of paper with grid marks drawn on it for composing. You'd be surprised at how much easier it is to get the image lined up properly that way. It is difficult to see the black blades of the easel with only the projected light hitting them, but that's also rectified as well. I've simply covered the edge with a piece of masking tape. It's not white like the paper, so you can see the difference; and you always know exactly where it is in relation to the image. Rocket science it ain't.

panastasia · May 3, 2009

Christopher Walrath said:
If you turn on the enlarger to compose another print you lose the safelight for placing paper on the easel until after the timer has run out.

QUOTE]

Or just use the toggle switch without running the timer, to turning the enlarger on/off.

BetterSense · May 3, 2009

Hows the homemade meter?

Very good! It's not a proper meter, but a comparator. It basically has a bar graph with a 4-stop total range in 1/4-stop steps, and a sensitivity dial. You plop it on your paper, adjust the graph to some middle value then you can use it to compare brightnesses for changing between print sizes. The photodiode is a very small point so it's easy to compare using say, someone's forehead.

RJS · May 7, 2009

Dodging and burning are a whole lot easier with the safe light off. I tried having it on and coiuldn't see the image on the paper nearly as well. I can't imagine a reaon for wanting it on while exposing the paper.

AshenLight · May 7, 2009

I use the RH Designs ZoneMaster enlarging meter and it will not give a proper reading with the safelights on. I have it connected to their StopClock Pro and it controls the safelights while I'm taking readings.

Ash

BetterSense · May 7, 2009

I think what I will do is make another, dim safelight and plug it in to the wall straight and have my current bright safelight only be on when the enlarger is off. That way when the enlarger is on, I can still see at least a little bit.

removed account4 · May 7, 2009

it is funny, i thought it was one of those things that the timer companies did just to confuse everyone ...
i have light outlet and a pull string for my safelight ( always on, unless film is out ) and have never had trouble burning and dodging
with the light on ... i have had trouble burning/dodging when i make contact prints .. it is a 300 watt bulb and it is sometimes hard to get used to
to (burning + dodging) with so much light ...

sorry for being so clueless, but why would someone need an enlarger meter ?
to check the evenness of light cast down from the enlarger ?
... or to help give a better understanding where to start a test strip at ?

Sirius Glass · May 7, 2009

jnanian said:
it is funny, i thought it was one of those things that the timer companies did just to confuse everyone ...

Or plug your enlarger into that outlet and when you turn the enlarger on, the power supply will turn it off!

Steve

srs5694 · May 7, 2009

jnanian said:
sorry for being so clueless, but why would someone need an enlarger meter ?
to check the evenness of light cast down from the enlarger ?
... or to help give a better understanding where to start a test strip at?

Both of those, but mostly the latter. They can also help determine the required contrast for a negative -- you meter separately off of the highlights and shadows, and use a little dial/calculator thing to determine the contrast grade.

At least, that's the theory. I've used a couple of enlarger meters, and I've found that they steer me wrong more often than they steer me right. Maybe mine are dodgy or maybe I'm using them wrong, though. Either way, I've stopped using them.

removed account4 · May 7, 2009

Sirius Glass said:
Or plug your enlarger into that outlet and when you turn the enlarger on, the power supply will turn it off!

Steve

srs5694 said:
Both of those, but mostly the latter. They can also help determine the required contrast for a negative -- you meter separately off of the highlights and shadows, and use a little dial/calculator thing to determine the contrast grade.

At least, that's the theory. I've used a couple of enlarger meters, and I've found that they steer me wrong more often than they steer me right. Maybe mine are dodgy or maybe I'm using them wrong, though. Either way, I've stopped using them.

thankfully i haven't been there yet

Why do enlarger timers turn the safelight off during exposure?

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