[AZ-Observing] Re: color is not important was Re: How deep can you see?
- From: "Jack Jones" <spicastar@xxxxxxxxxxxxxxx>
- To: <az-observing@xxxxxxxxxxxxx>
- Date: Sun, 15 Dec 2002 22:44:09 -0700
On top of all that I still have to say that ANY light is 'deleterious'
to complete dark adaption, which takes ~45 minutes to get down to the
very bottom of the curve. You just go thru the lower part of the
20-minute curve again and again when you turn from your star charts to
your eyepiece and back (some a greater section of the curve than others,
right Russ? :-)) Any more than say, 200-300 photons coming in, and you
walk back up the curve to the 10 to 20 minute adapted level. If you
enjoyed seeing the little companion to Rigel, for instance, (aperture
size will work against you!) that'll send you up to <10 minutes dark
adaptation with a dot in the middle of your vision. If you get a half
million photons from a momentary flash from someone's backup lights, you
get to start over. Sorry, but we've got to dig down in our astronomy
junk and haul out that eyepatch. Use it to preserve your favorite
observing eye when you hunt for something on the charts or laptop or
DSCs, and then switch it over to your chart eye when you look into the
eyepiece. If you don't believe it's effective, look at the background
field in your eyepiece and then switch to your starchart eye. See a
difference? The greater the difference, the worse you are polluting
yourself with your chosen flashlight of whatever color or brightness.
Jack Jones
Saguaro Astronomy Club
Lunar List Awards and
Messier Marathon Co-coordinator
Phoenix AZ
spicastar@xxxxxxxxxxxxxxx
>
> I think the reason that red light is less deleterious to dark
adaptation is
> that rods are less sensitive to red light than are cones. Light
bleaches
> Tom
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