P3D Re: Aerial hyperstereo

[Robert Thorpe <thorpe@xxxxxxxx>]

Mark Josephson wrote:
> 
> Well, looks like I'm going to be able to go up in a plane and take some
> panoramic aerial hypers of my hometown (Chicago) before I move away next
> month.

Tips:

1. Shoot at the fastest shutter speed you can. Camera jiggle and
movement
will be your biggest problems.

2. Set you focus to infinity and adjust your aperture to match your
shutter
speed. Depth of field will not be a problem. In other words, don't worry
about hyperfocal distance, the nearest thing that you can possibly
encounter
will be the Sears Tower and hopefully you will still be far enough away 
from it that it will be sharp.

3. Film speed - with iso 25 film and using the sunny 16 rule-of-thumb,
your
aperture should be about f2.8 with 1/1000 shutter speed. That should
still
be ok since depth of field is not a factor.

4. You will have more dramatic lighting early in the morning when the
sun is
low, but your shadows may be deeper.

5. Fixed wing aircraft are required to stay at least 1000 feet off the
ground
in populated areas. This is pretty high up and your shots will need to
be
farther apart to get the right stereo effect. I used to fly in
helicoptors 
which are allowed to fly lower. I liked 300-500 feet and a 35mm lens for
punch
but you may not have this opportunity. If you can get the pilot to land
at
Miegs, you may be able to get some lower altitude shots. You may also
run
into some restrictions because of the O'Hare flight zone.

6. Try to shoot with the window open. Perspex is always scratched. A
high
wing Cessna is often preferred.

7. This seems obvious but remember to keep the camera level with the
horizon.
In a banking turn it is easy to tilt the camera.
======================
Robert Thorpe
Cedar Rapids, IA
thorpe@xxxxxxxx
http://www.skep.com


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

End of PHOTO-3D Digest 3454
***************************