Ted: Thanks for the description of what's happening to my eyes........makes lotd of things "clearer".
Incidentally, my wife's new Mercedes has "ambient lighting" surrounding the interior at night which is Amber, I'm told that I can change it to red or blue, but I agree that the amber is a very nice surrounding for night driving. The ambient lighting comes from strips of LEDs??? Along each side of the door trim moldings under the window sill both front and back. Best, Ron C. -----Original Message----- From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Joe Della Barba via CnC-List Sent: Friday, September 19, 2014 10:07 AM To: cnc-list@cnc-list.com Subject: Re: Stus-List Red light myth? Red light for night vision is NOT a myth, but there are some issues with it. I have long experience with it both sailing and as a pilot. Any decent camera has a lens made of different types of glass layered together or otherwise designed to focus red, green, and blue light in the same spot. Our eyes do not - we have a simple one-element lens optimized around green light. Red light is very poor for doing fine detail work or reading small print. Most people lose flexibility in their lens as they age and usually this results in not being able to focus as close as before - i.e. reading glasses. This also affects the ability to focus red light. I used to teach in a plane that only had red panel lighting and some of my older students had a very hard time reading the instruments while I - younger back then - had no issue at all. Red light is also horrible for reading charts, all the color detail washes out. We had another plane with white instrument lights and red area lights for the cockpit. I liked that one the best, we would turn up the red light enough to see what was what and turn down the instrument lights until they were a very dim yellowish white. If the white is dim enough it didn't ruin our night vision and was much easier to read than just using the red overhead lights. Mercedes and Porsche use a similar idea, or at least they did back when I had them. Both cars used black dial instruments with orange-red needles and white lights. You could dim it way down and still read the gauges just fine. BMW uses an orange-red that works pretty well and Audi uses pure red. Once you get past a "certain age" the organge-ish (amber?) color is easier to focus and I think what you lose moving away from pure red you gain by not needing it to be so bright* to focus. * more camera tech. Bright light, for both cameras and your eyes, means reducing the amount of light with your iris getting smaller or the mechanical version in a camera. Due to the physics involved you gain depth of field by doing this, so things are in focus in front of and behind the focus point. If you are far sighted, you might be able to read something a lot closer in bright light than in dim light because of this and red light makes this happen even more. So - IMHO and I Am Not An Eye Doctor - I have set my boat up with all red lights for night sailing. The red is fine for getting around and finding large objects. My compass has big enough markings to look fine in red light as do the engine gauges. I can deploy a small dim white light at the chart table if I need to, but it is a rare occasion now for me to work on paper charts. I do set the computer plotter to be as dim as it can be an turn down the screen brightness on the laptop to the lowest setting, but still in color. If I shift it to "night mode" with black background I seem lose a lot of detail. I do see many plotters WAY too bright at night. I see boats going by with the helmsman clearly illuminated by the plotter. I do not see how they can see even as far as the bow. Joe Della Barba Coquina C&C 35 MK I _______________________________________________ This List is provided by the C&C Photo Album Email address: CnC-List@cnc-list.com To change your list preferences, including unsubscribing -- go bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com _______________________________________________ This List is provided by the C&C Photo Album Email address: CnC-List@cnc-list.com To change your list preferences, including unsubscribing -- go bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com
