RE: model rocket photos

[P3D <PgWhacker@xxxxxxx>]

Subject:     RE: Model Rocket Photos.
Sent:        3/12/97 8:26 PM
To:          photo 3D postings, photo-3d@xxxxxxxxxxxxxxx


    Lots of speculation lately about stereo photos from a model rocket.   
Thought I'd share some real world experience about stereo perception from 
altitude.


    My other hobby is paragliding, so I've spend hours in the air between 
200 and 5,000 feet above ground level.  I never take my stereo camera 
with me because, having been there, I know the 3D shots that result will 
be disappointingly flat.
 
    Terrain features are important to paragliders.  Try to touch down on 
the downwind side of a ridge and you're sure to be caught in an eddy, and 
likely to suffer a wing collapse and a long fall.  (Only the last inch is 
any trouble at all.)  At 1,500 -2,000 feet agl a 150 foot -- that's 15 
stories!  -- ridge looks just like a flat field.  I almost got killed 
learning that one.  It's not till you get within a few score of feet that 
3D features really stand out.  Above that you assess spacial relations 
mostly by size and shadow.

    How wide a stereo base is needed at altitude?  I've taken 3D shots of 
Randolph, Utah from atop 1,400 foot Crawford Ridge (we para-waited 3 
days, and the wind never did come in right), using a _30 yard_ stereo 
base, and still gotten little stereo effect.

    The best way  to get stereo views from the air would be to attach a 
camera to a kite.   Ideal altitude.  Easy to send a shutter trigger 
drogue up the line.  Somebody has even written a book explaining how.




Greg Kane
Denver

PgWhacker@xxxxxxx





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