Gralab 300 usage to avoid fogging film/paper?

[chassis]

Hello all,

I recently acquired a Gralab 300 timer, the type I used many moons ago. I forgot the procedure - I think I used it as an enlarger timer, but I remember the dial marks glow in the dark.

Do I need to take any precautions with this timer to avoid fogging film or paper? Or is the photoluminescence of the dial insignificant? I simply can't remember how I did this years ago. Thanks.

[chassis]

Thanks Dan.

[David Swinnard]

I just throw one of my darkroom towels over the face of my old Gralab while I'm loading sheet film into holders or roll film into tanks. I've not had any issues with paper.

I used it as an enlarger timer (doing f-stop timing since I had to reset it manually every time anyways) for twenty years only stopping when I found a used f-stop timer (an old Nocon). It's still my film processing timer.

[Gem Singer]

I charged the dial of my Gralab 300 to it's max. by exposing it to fluorescent light for a few minutes. Then tested it's effect on HP-5+ film.

While the dial was glowing brightly, it only showed an effect if the film was touched directly to the dial. Other than that, it showed no visible effect on the film at normal working distance (3-4 ft).

It's a good idea to cover the timer dial while loading film. I do it out of habit. However, it's not actually necessary.

[Brian Ellis]

I agree with Gem, my Gralab was on a shelf over my left shoulder, about 6-8 feet away from the film, and it didn't create a problem.

[jp]

I keep my darkoom lit with only safelights for a few minutes before going dark and loading or developing film. This lets the gralab dim a little. I also put it on the opposite wall from my trays so I am between the timer and film. That seems to be plenty of precaution. As for paper, just don't set B&W paper on it, and it's fine.

[jayabbas]

I just throw one of my darkroom towels over the face of my old Gralab while I'm loading sheet film into holders or roll film into tanks. I've not had any issues with paper.

I used it as an enlarger timer (doing f-stop timing since I had to reset it manually every time anyways) for twenty years only stopping when I found a used f-stop timer (an old Nocon). It's still my film processing timer.

A bit off topic but how do you like f- stop timing? I'm researching it and it looks very intuitive in my eyes. I saw the RH design timer -- $$pricey -- any others out there? Thanks

[E. von Hoegh]

Never had a problem that I could trace to the Gralab. I kept it on a shelf just above the trays, and used it developing film and paper. Loading film in holders and drums was done on an area about 4' from the timer, which would have been over and behind my left shoulder.

[Jim Michael]

I would think that testing unexposed film for fogging effect is not a valid method since you may be well below a threshold that may exist in exposed film. A more accurate test might be to expose two sheets to 18% grey, expose one to the timer dial, and develop both together.

The source is subject to inverse square law so the exposure from the dial will vary as factor of 2 per distance change in f-stop feet.

[Larry Gebhardt]

A bit off topic but how do you like f- stop timing? I'm researching it and it looks very intuitive in my eyes. I saw the RH design timer -- $$pricey -- any others out there? Thanks

Here's an alternative to the RH Designs. http://www.darkroomautomation.com/fst.htm

I use an RH Designs version for the Ilford Multigrade system and I love the thing. I wouldn't go back to a regular timer if I could avoid it. But you could also create a table of times to use with your timer. It's one extra step, but it saves some cash. Might be a good way to try out the concept before making a purchase.

Here's a link to an fstop table of times http://www.darkroomautomation.com/su...stopstable.pdf