Safelights?

maxbloom · Jan 11, 2007

Okay this may be a very simple question with a very simple answer, but it's sort of dumbfounding me. Why on earth does traditional b&w film need to be loaded/unloaded/whatever in complete darkness? If you're working with a film that isn't red-sensitive, then why can't you work under a red safelight?

Nick Zentena · Jan 11, 2007

Who said it wasn't red sensitive? Stick a red filter on the camera and go shoot a frame. What do you end up with?

David Brown · Jan 11, 2007

maxbloom said:
Okay this may be a very simple question with a very simple answer, but it's sort of dumbfounding me. Why on earth does traditional b&w film need to be loaded/unloaded/whatever in complete darkness? If you're working with a film that isn't red-sensitive, then why can't you work under a red safelight?

Modern films are panchromatic. I.e., they are sensitive to all colors. By "loaded/unloaded", do you mean in the camera, as in roll film/35mm; or are you talking about processing and/or loading sheet film holders?

Neal · Jan 11, 2007

Dear maxbloom,

You can purchase orthochomatic film that is not red sensitive. This type of film can be used with a safelight. I don't know if it can be found in sizes other than sheets. Here is the data sheet for HP5+, a panchromatic film.

http://www.ilfordphoto.com/Webfiles/2006216115453172.pdf

The portion of the curve above around 600nm is the area sensitive to red.

Neal Wydra

Loose Gravel · Jan 11, 2007

Most BW films are pretty dead beyond 625 to 650 nm. It would seem that some really deep red LEDs would work for a safelight, even for pan films. As an example, try photographing red LEDs. The deep red are difficult to image. These days, with all the new LEDs, you might find one at 675 nm that would work. You'd barely be able to see it, too, unless you are red color blind, and then not at all.

maxbloom · Jan 14, 2007

The only ortho rollfilm that I know of is made by Maco.

Loose Gravel · Jan 14, 2007

http://dkc3.digikey.com/PDF/T071/2104.pdf
and
http://dkc3.digikey.com/PDF/T071/2057.pdf

These are pages from an electronics supply house called Digikey. If you look around the pages, you will see some 697 and 700 nm LEDs. These may work. I don't think they will fog film, but you may not be able to see them either, especially if you are the slightest bit color blind in the red. Next time we make an order at work, I will get some and try.

Loose Gravel · Jan 19, 2007

I've found some 690 nm LEDs that are 'bright'. I guess they are bright if you can see them. Anyway, I've got some on the order list and I'll let you all know what happens.

Safelights?

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