safe lights

[andrew_poterek]

I bought a darkroom set off of my uncle a year back and all was going fine

until my safelight burned out. I rummaged through the excess stuff and found a

Kodak Brownie Darkroom Lamp Model B. It has a simple black plastic base with a

7 W bulb and a plastic cup that fits to the base. The cups that came with the

lamp are green and yellow. I know when developing B & W RC papers you need to

use OC/ Amber filters for safelights. I was wondering if this yellow is safe to

use and what the green is good for. Any help would be much appreciated. Thanks

[lex_jenkins]

Green is usually okay for RC papers and some graded papers. If it's a really dark green it may have been intended for developing sheet film by inspection. If so, it'll be safe for most papers but very dim.

 

Dunno 'bout yellow, never used it. Easy enough to test compatibility between papers and safelights anyway, and always a good practice.

[alex_lofquist]

The yellow filter is probably an OA filter used for general darkroom printing.

[andrew_poterek]

sorry the picture didn't turn out so I'll try again

[andrew_poterek]

So if my paper specifies that you should use OC filter, this most likely would not work right?

[bob_sunley]

Test it first.

Dig around on the kodak web site for a safelight testing procedure.

[sagephotoworld.com]

I used to use a red or amber lamp cover with a 25w bulb.

 

The acid test - turn the light off, pull out a sheet of paper remembering to close the box. Put a weight on top of the paper then turn the safelight on. Sit down for 20 minutes and read a newspaper with the safelight. Then pull the paper out and pop it into the developer. If you can see wher eyou had the weight then you know the light isn't safe.

 

Outside my bathroom in Britain there was an amber sodium street lamp. I very often at night worked by the light of that lamp. It was quite bright and didn't fog b/w paper.

[albert_richardson1]

The red and green covers are probably for handling film. Green would work with infra-red films and red would work with orthochromatic films. Panchromatic films are best handled in complete darkness. The yellow allows you to see when handling papers for making prints.

[Monophoto]

Andrew -

 

The usual safelight filter used in printing is the OA. It's a pukey yellow-amber color.

 

In the distant past, it was common to use a red filter. In the earliest days of photography, both paper and film were orthohromatic, and a red filter was ideal for that material. Some people, myself included, continued to use a red filter with more modern papers just because we had one.

 

The green filter was used for inspection processing of sheet film. Modern films are sensitive to all colors of light, so they have to be processed in total darkness. However, they do lose sensitivity greatly during processing, and it is possible to use a faint green safelight for brief periods after the film has been partially developed. Inspection processing is a practice of looking at partially developed film using a green safelight to determine if it has been processed sufficiently.

 

The advantage of inspection processing is that it allows the processing to be tailored to the needs of individual sheets of film. However, it's an acquired skill and most people have difficult judging when partially developed film is "done".

[sagephotoworld.com]

Film processing should always be done in total darkness. Safelights are used for paper only.

 

Ilford Multigrade paper is not sensitive to amber or to red.

Colour negative paper is not sensitive to dim green light.

 

Colour transparancy paper like film is sensitive to all light and should be processed in total darkness.

 

I had my own darkroom for many years and developed and printed just about everything.

[alex_lofquist]

Andrew is correct in that the green safelight filter can be used when developing pan film. It is only used briefly at about 1/2 way through development with emulsions that have been desensitized prior to it. Usually this was only done with sheet films that could be inspected individually.

[alex_lofquist]

I should have said that Louie was correct.

[andrew_poterek]

Louie - I dont believe I have ever come across a OA filter for safelights. All of my paper states a OC should be used and when looking online I only come across red and OC filters for safelights. Where would you find an OA light? Do you suppose the yellow cup shown in the attached picture is about what you described?

Rhys Sage - Thanks for the acid test info, I'll probably try that out just to make sure things are as they should be.

To everyone else, thank you for you feedback

 

If anyone has worked specifically with this safelight system I would appreciate hearing any feedback you may have. I think I'm perhaps getting overanxious about messing things up, as I'm sure the yellow cup will do just fine. Regardless, I shall run an acid test sometime soon and let everyone know how it turns out for future referance.