Darkroom Safelight Filters

[themoleman342]

I've finally gotten a darkroom up and working. So now I'm trying to tweak it to the best of my ability (and wallet). The space where I work is not very well contained (quite a large basement room) and my centrally placed "beehive" Kodak safe-light with OC filter seems to have a strong drop-off in light on the edges of the working area. I found the same safe-light with a No. 11 filter. It was one I didn't recognize (my developing manual from Kodak doesn't even mention this number) but it cost next to nothing so it was worth a shot. I found the specs on their filters: http://www.kodak.com/global/en/professional/support/techPubs/ti0845/ti0845.pdf

Looking at the transmittance charts it looks as if the No. 11 covers the same spectrum as the OC filter and quite a bit more. Now if it doesn't let through the same wavelengths am I wrong to assume it won't effect the enlarging paper? Thanks for any input!

[lulalake]

[themoleman342]

Yes, talk about deep, it takes a 75w bulb in the top just to see the color. That's got to be a problem...

[lulalake]

[themoleman342]

Thanks for your help. What would you recommend the wattage to be to give out an acceptable working light with traditional enlarging?

[lulalake]

[Rob Leslie]

Using your darkroom for BW printing you should have and are able to have a very good standard of illumination. You need to have levels that allow you to clearly see you print developing and are able to apply a few dev tricks as well as remove it at the correct time. A good BW darkroom should be so bright as to need a switch at the enlarger to turn the lights off to help with focus.
All papers have safelight recommendations but the usual test of darkroom safelights is to take a sheet of your usual paper out of the box in darkness, lay it on the workbench and place something like a few coins on it. Turn on your safelights and leave for an hour then develop the sheet. If everything is Ok the sheet should be perfect white with no sign of the outline of the coins or whatever you used.
Most pro darkrooms have a great standard of indirect reflected light which gives a nice even illumination which meets the needs of health and safety. To save money make your own units using gels.
A 75W bulb for a 6 inch safelight sounds too high. That is usually the max for the 12 inch rectangular ones.

[themoleman342]

I'd agree that 75w sounds to high but in all honesty the other safe-light with a 7.5w bulb and OC filter gives off about 3 times as much light as a 75w bulb and No. 11 filter. I will try the coin trick. It sounds like a very worthwhile idea.

Just to make this known. Everything for this darkroom cost me about $150. I mean everything. Some highlights: The enlarger I got for $13. The componon lens: $5. The 600 sheets of 11x14 ilford fiber paper: free...I sound like a credit card commercial. So there is quite a bit about this that I don't expect to be absolutely perfect.

~Marc