RE: Darkroom light

Good day to you Dennis,
 
A clever experiment.
I give you my interpretation of your research-results.
Due to the reciprocal effect your paper stays bright white or may I say:
unfogged. You may remember that at low light levels exposuretimes have to be
substantially raised. The milky-white globe probably reflects and absorbs
part of the light. The reduction of light level causes no devellopable image
since it is too low.
 
Maybe you will want another lamp. That is to say almost every photographic
black and white paper is absolutely unsensitive to a certain frequency in
the yellow to olive-green part of the visual spectrum. That specific
frequency may be slightly different for different kinds blue-sensitive black
and white paper.
 
Maybe you will want to check out the safelight properties at the website of
your paper's manefacturer. Few things are such a blessing as sufficient
light in the darkroom, since that allows you to judge what you're exactly
doing.

-----Oorspronkelijk bericht-----
Van: Bill Erickson [mailto:erickson@hickorytech.net]
Verzonden: zondag 20 januari 2002 20:33
Aan: pinhole-discussion@pinhole.com
Onderwerp: Re: [pinhole-discussion] Darkroom light

Should be just density.

----- Original Message -----
From: Dennis Johanson <mailto:dennis.johanson@telia.com>
To: pinhole-discussion@pinhole.com <mailto:pinhole-discussion@pinhole.com>
Sent: Sunday, January 20, 2002 2:03 PM
Subject: [pinhole-discussion] Darkroom light

I am planning to make a darkroom out of a rather limited space (floor about
1 by 1,5 meters), and it seems possible to find room for the equipment
necessary - but definitely not anyhing else.
 
I put a yellow-green darkroom bulb in the existing wall socket and placed
pieces of photo paper where I intend to have the enlarger as well as the
developer tray, and covered one half of each paper (one vertically and the
other diagonally in order to be able to identify them later on). Then I
turned the darkroom light on for five minutes. Thereafter I developed the
pieces of paper in total darkness. Unfortunately the papers had been
affected by the light. Then I covered the lamp bulb by a milky-white glass
globe, tested once more, and the papers came out shining white from the
developer tray. So, as long as I keep the globe on everything will probably
turn out fine.
 
Finally, here comes what I am wondering about. Does the globe work like a
filter reducing one colour and enhancing another? If so, which? Or does the
milky-white globe just function like a dimmer reducing the existing
yellow-green light without adding or deducting anything?
 
If anyone can enlighten me I shall certainly appreciate it.
 
Thanks!
 
Dennis
Received on Mon Jan 21 05:35:11 2002