Need gel numbers for Thomas Safe light filters
lots of threads here talking about replacing filters in these Thomas safe lights, but no one seems to ever give the actual numbered or code of Roscoe/Lee filters. Adorama and B&H have both discontinued carrying replacements and Freestyle sells sets of 2 for $50. Ouch!. I have all good glass, I just need to know what the gel is in between the glass. Amber and Red, Plus whether it is a piece of Flame retardant SPUN or is it really just tissue paper?
I have one hanging and would like to replace and one I indeed on putting up for sale here. I figure it would go easier if I replace the gel first.
I just put a string of LED lights from EBay. Cheap and energy efficient.
I have a Thomas Duplex too. It hums so I might not use it as much now.
The Roscoe R19 Fire filter is the closest to correct. I use it to fortify my existing Duplex B&W filter set.
It does a near-perfect job of filtering out the secondary and tertiary sodium emission lines that are the true cause of all the reports that the Thomas units fog paper just because they are too bright. That's not it. It's the emissions from those non-primaries in the green and blue sections of the spectrum that are causing the fog. After fortification with an R19 I once tested a sheet of (pre-flashed to threshold) Kentmere Bromide #3 for over 30 minutes with the vanes wide open with no evidence of safelight fog whatsoever.
Last edited by Ken Nadvornick; 03-08-2012 at 05:08 PM. Click to view previous post history.
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Thanks for the response. I finally found two phone numbers and addresses for Thomas instruments, but both were disconnected.
I went to my local stage lighting supplier and picked up a different catalog for Lee filters. I had the Cinematographer's Edition sample book, but on comparison, the filters in my thomas are in between everything. They tried to help, but I ended up calling Lee Filters. The guy I talked to suggested 015 - Deep Straw for Amber (yellow tape) and 024 - Scarlet (red tape). I searched under a dozen different ways and at some point I found another thread here (which i can't find again of course) and it was educated guessing, based on the Spectral chart of of each filter color. It mentioned Lee filter 026 - Bright Red or 027 - Medium Red as their spectral charts read at blocking the wavelength up to 550nm-600nm. I believe 700nm is infared and these Thomas safelights use both the yellow and red filter (winging closed w/ all filters in) with Ortho film according to this instructional PDF to the light ( http://backglass.org/duncan/darkroom...ight_instr.pdf ).
How much "nm" needs to be blocked for Ortho?
And the thread fell short, because there is no mention of which Lee filter for the Amber. So, How much "nm" needs to be blocked by the Amber one while processing B&W paper?
I now which I could change the title.
After reading a little more, I guess my question "How much "nm" needs to be blocked by the Amber one while processing B&W paper?" can be better asked as, What part of the spectrum of the "nm" needs to be blocked by the Amber filter for B&W paper?
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I also called Freestyle yesterday and spoke with a very nice person about the issue. They did not have the info on what these mystery gels are, but did offer to make a call the the supplier of the filters they offer @ $49.99 a set (new glass, gel, tissue and taped up). This was the reply:
This is regarding our conversation about the Thomas Safelight Filters. Unfortunately we are not able to provide the filter separately and the company is not willing to inform us of what filters are in the piece we sell. You are more than welcome to purchase the filter sets we sell and try to discern what exactly is inside the set.
If you have any more questions feel free to ask.
SECRET, sshhhh. I don't know who their supplier is. I guess I understand that if you have information that few seem to have and you are able to turn a small profit from it, that is your purgative. I can't say I might not do the same, but I still feel a bit slighted knowing my problem could be fixed with $10 of gel instead of spending $100 @ Freestyle. Of course it probably only cost about .35¢ to make this $28 t-shirt I'm wearing right now. Anyway, Thank You Freestyle for trying to help when do didn't have to.
Moving on, I bought some different gels today based on the Spectral charts. The Red is pretty more dead on with 026 - Lee filters. The filter in the Amber glass of my Thomas lies somewhere in the area between 207 & 208 which are FULL O.C.T. + neutral density. Except the Thomas has a bit more magenta in it, though 207 - 208 kinda make sense, right? Help me , Yellow and Red make Orange - Red Blocks Blue? and Yellow Blocks Green? Darkroom paper is Green and/or Blue sensitive, right?
Of course, I didn't buy either of those. I did get a 135, 789, 777 all Lee, we shall see hopefully this weekend.