DIY safelight coating?

SimonFarrington · Aug 6, 2009

Has anyone here ever tried coating their own safelight bulbs?

The ones you can buy are pretty expensive, but it would stand to reason that you could buy the coating and make your own.

Any one know if it's made/sold separately?

Simon

sun of sand · Aug 6, 2009

If you can stand the smell
spray paint

I did many dark red/black that were as safe as any filter I have
The smell can be a bit much as the bulb was a 40 wt ..maybe a 60wt even - was dimmed way down due to paint
No doubt amber and green can be done just as easily

SimonFarrington · Aug 6, 2009

Does it just smell to paint it? Or while it is in use?

BetterSense · Aug 6, 2009

http://www.dealextreme.com/details.dx/sku.1776

DannL · Aug 6, 2009

Here's a list of filter colors and their uses.

http://www.kodak.com/global/en/professional/support/techPubs/ti0845/ti0845.pdf

The details are in the transmission graphs. I use the Kodak OC and Kodak No. 10. filters, both having unique properties. I don't know which paints could accurately replicate those sensitometric curves.

So, which color would you choose for your first bulb?

willem · Aug 6, 2009

I agree to the reaction of BetterSense: It is much easier to use LED's and build your own safelight. The LED's will provide more safety that cannot be realized using paint.

willem

2F/2F · Aug 6, 2009

I have not tried it. I just don't see the point. I have gone through exactly zero safelight bulbs in the last three and a half years since I set up my current darkroom. It cost me under four dollars to get the red one to fit the empty Kodak safelight that I picked up for free back then. The bulb in my zero-C safelight has been in there since the early '80's. When it goes, I will put in the other one from the two-pack it came in, which has been stored with the rest of my darkroom stuff since.

I believe I have heard people on this Website state that rubylith can be used over lamps or over windows as a safelight filter. Makes sense to me. That is what it was designed for, really: to block light.

Ian Grant · Aug 6, 2009

Not surprisingly I actually have quite a few formulae for making your own Safety light coatings, they were published regularly before WWII.

It's also remarkably easy if you have the correct dyes. The early specialists in the field were a pre WW 1 British company, and they still exist and most photographers will have heard the name, Wratten. The company - Wratten & Wainwright was bought by Kodak in 1912, C.E.K. Mees moving to Rochester to set up Koak Research, and Wratten to begin Kodak Research, Harrow.

Personally I'm not interested in trying for myself, but I know an enterprising company did make their own in the late 70's & 80's in the UK.

Here's some formulae from around 1910, see the attachment. Remember that Panchromatic plates were only just become available, so these aren't safe for films except some slow Orthochromatic ones. I doubt any of these formulae would be safe fore Multigrade type emulsions.

Ian

David A. Goldfarb · Aug 6, 2009

Thanks for posting that. It's a good reminder that people actually used to make their own safelight filters, and one never knows when we'll need to know how to do that again, and when we do, we'll probably be making things like ortho plates with formulas from around 1910.

In the meanwhile, though, used safelights are plentiful and cheap, so I'd recommend just looking on eBay and buying as many safelights as you think you might need.

Ian Grant · Aug 6, 2009

David, there's a whole raft of excellent formulae for POP papers, lists of dyes for Panchromatic "Colloidon" emulsions etc in older books and most of the information is from Research papers. You just have to know where to look.

Eastman started out that way then bought in technology re-investing all the time.

Here's more modern safelight coatings, well only by 25 years or so 1935, but a greater rangem from the 1935 BJP Almanac (re-laid out for clarity).

Ian

DIY safelight coating?

SimonFarrington

sun of sand

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willem

2F/2F

Ian Grant

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