The use of red light in darkrooms, went out many decades ago with the introduction of pantographic film emulsions that were sensitive to all colors. Orthographic film as used in the early days of photography were 'blind' to red light, hence the use of red in the darkroom. For over 50 years, darkroom 'safe lights' have been yellow-amber.
Safe lights are used so we can see, but the color is chosen to make it a color that the film doesn't see. Its not necessarily best for our vision, just best for the film or other light sensitive material. I've heard that night lighting inside submarines is blue to protect the eyes for those that are transitioning from inside to outside. ...bill nr4c -----Original Message----- From: Ron D'Eau Claire [mailto:r...@cobi.biz] Sent: Monday, September 23, 2013 8:48 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KX3 Backlight color will remain amber Also, human vision has the lowest acuity in the red region. That is, we see less detail in red illumination. 73, Ron AC7AC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html