film fog

Huck · Jan 28, 2014

How much does the reflection from the darkroom clock fog the film?

bdial · Jan 28, 2014

I've never found it to be a problem, but haven't tested either.
In general if the film is no closer than 3 or 4 feet, it shouldn't be a problem.

argyrotype · Jan 28, 2014

1.put a sheet of 4x5 film on your counter near the enlarger, emulsion side up..

2. place a quarter on the film.

3. after 5 minutes, develop the film and look for the circle.

4. If you only see clear film, stop worrying.

Jeff Searust · Jan 28, 2014

how bright is the clock? -- is this a radium dial clock or a led clock? -- My Gra-Lab timer has Very bright radium (glow in the dark) numbers and dials but is MADE for the darkroom. I also have multiple led numbers on my enlarger timer---looking around there are a lot of things that glow or light up in the darkroom but all were expressly made for the function.

Gerald C Koch · Jan 28, 2014

The human eye is far more sensitive to light than any conventional film. What appears to be bright to us is not seen by the film. When in doubt do a test.

fotch · Jan 28, 2014

I don't know how much however, if it seems to bright, cover it and thus eliminate it and you don't have to wonder. JMHO

gone · Jan 28, 2014

Your enlarger is probably leaking 3 times as much light as the clock. I wouldn't worry about it.

MattKing · Jan 28, 2014

momus said:
Your enlarger is probably leaking 3 times as much light as the clock. I wouldn't worry about it.

You probably don't want to have your enlarger turned on when you have undeveloped film out in your darkroom .

I have friends that have towels attached to the top of their Gralab timers that they flip down in front of the timers when photo-sensitive materials are out.

Personally, I think that is most likely unnecessary. I would just position the timers so they are facing away from the materials.

As far as LEDs on equipment, I would suggest turning off or screening what you can, and testing with respect to the rest.

MDR · Jan 28, 2014

Depends on the film doesn't it Delta 3200 pushed to 12500 might get a little fogged. If you get closer like 5 cm or so you might get some fog on ISO 100 and higher films.

Ian Grant · Jan 28, 2014

Gerald C Koch said:
The human eye is far more sensitive to light than any conventional film. What appears to be bright to us is not seen by the film. When in doubt do a test.

On an APUG trip to Cornwall (about 4 years ago) I stayed in a B&B and changed sheet films (LF) in a bedroom with poor curtains and sodium street lighting. At first I thought it was dark but as my eyes adjusted i could see what I was doing !!! No problems which was rather surprising.

Ian

Tom1956 · Jan 28, 2014

The trick to wondering if your darkroom is too light when you're loading film is to just do it with your eyes closed and hope for the best.

Bill Burk · Jan 28, 2014

I always rely on Murphy's law to prove that the clock dial is safe...

If you WANTED to expose film with it... you couldn't.

Gerald C Koch · Jan 28, 2014

The following article may be of interest. It details the light sensitivity of the dark adapted human eye.

http://webvision.med.utah.edu/book/part-viii-gabac-receptors/light-and-dark-adaptation/

One of the methods used to increase film speed involves a process called latensification. The film is exposed to a very dim light source for a number of minutes before exposure. I have done this several times and there is enough illumination for a person to walk about without bumping into things.

Sirius Glass · Jan 31, 2014

Never found it to be a problem.

cliveh · Jan 31, 2014

The only danger from your darkroom clock is if it falls off the wall onto your film.

Sirius Glass · Jan 31, 2014

cliveh said:
The only danger from your darkroom clock is if it falls off the wall onto your film.

"onto your film' should probably read "into your chemical trays". That would shorten your darkroom time for a while.

film fog

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