I have recently bought a new enlarger timer (a Viponel digital) which uses a green LED for the times. This is very bright even after I have adjusted it down. I wonder if it will have an effect on B&W paper as I thought most B&W paper is sensitive to blue and green light. I guess I could hold a piece of paper close to the LED for a minute or so and then develop it, to check, however I thought I would ask you folk first. I would of thought it would of been better to have a timer with a red LED.

-- sam smith (ssmith@hotmail.com), March 20, 2001

Answers

The dark adjusted human eye has its highest sensitivity to green light, and dark yellow/green is the safelight that's used with colour sensitive materials.
This is obviously Viponel's thinking behind the choice of green, but for use with B&W printing materials, it makes no sense at all.

-- Pete Andrews (p.l.andrews@bham.ac.uk), March 21, 2001.