P3D Re: Interesting visual phenomenon discovered.

[Bob Wier <wier@xxxxxxxxxxxxxxxxx>]

At 10:12 PM -0600 on 5/20/98, Greg Wageman wrote:


|Try this!  Only 10-15 seconds of looking at a white screen through
|red/blue glasses should produce the effect.  Interestingly, with both
|eyes open I don't notice anything unusual, but put a hand in front of
|one eye and the color bias is instantly obvious.  It seems to linger
|much longer than the time it takes to create it in the first place, too.

Yes - I find this effect extremely pronounced - it takes me maybe 
10 to 15 minutes to get my eyes "synched" as far as color balance
is concerned once I wear the glasses for an extended period.

Ancedote - Up around where I live, which is a mining area from 100+
years ago there are several mine tours available where you sit on 
an ore tram and are taken a mile or so into the mountain (this is
*real* stuff - not the amusement park versions). Typically these
tours take upwards of 45 minutes to an hour to cover. I remember
one time taking one where the last part of the track was laid out
in a relatively straight tunnel (adit) to the entrance portal. 
Having gotten relatively used to a rather low level of lighting from
incandescent bulbs, the daylight coming in from the outside was an
amazingly pure, piercing BLUE (no doubt aided by the fact that the
portal was at 9,000' elevation). One rather interesting operation
several years ago had actual hard rock gold mining going on during
2nd and 3rd shifts, and tours during the day. They eventually gave
up on the mining though, and are now just running tours. I guess
it's easier and more profitable to mine tourists :-)

The eye/brain's ability to compensate for color shifts is really amazing.
That's one problem I had with doing color printing in the darkroom
(using the CP5 chemistry for you old timers - nasty stuff) I could never
decide what I liked as far as color balance while the negatives/filters
were in the enlarger. I finally had to go to a color temperature meter
to get some kind of consistency.

THANKS

              Bob Wier
     mailto:wier@xxxxxxxxxxxxxxxxx
   1:44 AM Thursday, May 21, 1998
   Rocky Mountain College, Billings MT.
 keeper of the Photo-3d and Overland-Trails
mailing lists and the USA GPS Waypoint server



------------------------------