Re: Hale-Bopp

[P3D bob wier <wier@xxxxxxxxxxxxxxx>]

|  Can any other members of the group shed some light on this particularily
|the astronomers have other people had any success with stereos of
|Hale-Bopp. P.J.Homer

During mid - march, I took a number of "shifted foot" stereo pairs rather ad-hockly
(new word!) while on "spring" break up at home in Colorado at 8,000' elevation.
I tried a variety of exposure times, but got caught between using too slow film and
thus having to have too long exposures which resulted in the comet resembling
a waterfall, vs fast film which tended to "burn out" badly due to my wanting to have
the lights of the town in the foreground. The best compromise turned out to be about two
30 second exposures. However, the sky darkened noticibly between the two pairs (in the
evening) and thus I had to do some manipulation in Photoshop in order to come up with
a density match between the two prints which looked uniform (more or less). Then came
the problem of whether I should adjust the positions of each panel so that the image of 
the comet overlapped between the two pictures (which introduced slight downward and
sideways misalighment between the pair for objects on the ground) or match the ground
images precisely and let the comet "go wide" It would not have been so bad if the track
of the comet had been horizontal across the frame, but due to sky rotation, it is also
displaced vertically. 

The final effect is interesting. The comet and stars appear pretty much at the same
distance, which is beyond the mountains/town, but which is in FRONT of the blue
late evening twilight (some may recall that I noted that with a full moon at this
location during clear winter nights, the sky does actually appear faintly blue due to
moonlight scattering). 

I'm not sure how well it will come across, but I'll scan in the freeview pair and it
can be accessed at 

http://bobcat.etsu.edu/~wier

(Dang - if I'd only remembered to have taken the Realist with me instead of the
regular 35 mm, then I would have avoided the movement problem - On the other
hand, the image size would have been so small that I probably wouldn't have come
up with anything viewable - this stereo pair was using a zoom set at about 150mm
to frame the town, mountains, and comet) 

THANKS --

BW

                  Bob Wier
     mailto:wier@xxxxxxxxxxxxxxxxxxxxxxxx
    10:39 PM Wednesday, May 14, 1997
     Texas A & M University - Commerce
 keeper of the Photo-3d,  Overland-Trails
ICOM radio and LDS State Research Outline Guides
      "Heisenberg may have slept here. . ." 



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