LED & Sodium safelights
Please correct me on any of the things I'm going to say / ask.
Are the Jobo Maxilux or Thomas Safelight at all safe to use w/ negative color materials? For short exposure? Longer exposure? I believe that I've read that they are, but not sure.
Does the light from the Jobo Maxilux have a narrower wave length that a Thomas Safelight?Does this make it safer to use w/ B&W, Color? How hard would it be to make a DIY LED safelight that would be as safe as or possibly even better than manufactured safelights?
Thank you, Jay Drew
Colour negative film is colour sensitive - therefore, there is no safe safelight for it. If I recall, a green safelight can be used with colour photographic paper but at very low wattage and for very limited time. It's much, much safer to handle it in the dark.
The Duka Sodium safelights are safe with colour materials although you will need to do some trials with them to see how much light you can 'get away' with in your darkroom, and reflected light is also much better than direct light. It is also very important that they be allowed to fully warm up to get to the correct operating temperature which then provides the safest light. It is also important that you do not use them connected to your enlarger circuit that switches them off during an exposure or for focusing, this makes it a lot more difficult if you are using a colour analyser.
The LED safelights are typically designed to give a 590nm(ish) light and work very well with mono papers including multigrade. I have 2x Nova 5 Star units with 2x additional heads on each giving me six heads which are mounted at similar intervals around my 6ft x 7ft darkroom and aimed at the ceiling. At full power they do not fog my mono papers and I gave up testing after a 1/2 an hour exosure with max flashed paper did not show any fogging. I have not tried themfor colour yet as I have 2x Duka Sodium Units for that, although if I decide to use a colour analyser I may decide to try the LEDs instead. Their spiel suggests they should work.
I will go along with the DUKA sodium option they are superb. The bulbs will be quite old now but they are still available at a price - £75 UK pounds from a company called Process Supplies in London. Google the name and see what else they have to offer.
I have used the Thomas Safelights with the appropriate filter for color materials just fine with RA-4. I tested it out to 4 minutes safe after enlarger exposure before any added fog was visible.
Thank you all very much. That was extremely useful info. I thought I had read where Thomas safelights are very safe w/ B&W, & that some LED are barley save w/ color materials. Of course I would correctly test any combination of materials & darkrooms for light safety before use. I now know how to properly test for light safety. You don't just lay a quarter on an unexposed sheet of paper for a half an hour or so, & think it's just fine if the coin doesn't show up, as I did as a teenager. I am just blown away by being able to use any light when color material is out. Even as my skills increased working in total darkness, odd mishaps would occur where a small amount of light would be a God send to get out of a jam.
Thank you, Jay Drew