P3D astronomical stereos

[Peter Abrahams <telscope@xxxxxxxxxx>]

One recent comment on astronomical stereos is that 
> not even the astronauts orbiting in space get anything other than a
>"flat" view of our spherical earth.  Any stereography of planets, using
>hyper baselines (very hyper indeed!), or rotation of the subject, will not
>be much less realistic than a computer generated stereo of same.  

An astronaut can certainly get a wide variety of true stereos of earth by
using different focal length lenses and various intervals between
exposures.  Some of these could be extremely hyper if so desired.  I've not
seen a  stereo of clouds floating above earth but I can imagine it, and it
is beautiful.

Stereography of planets, using their rotation to establish disparity, can
be equally  convincing; you just need to get sufficient resolution to give
some detail to your depth.  The background will be flat, but the planet can
have any degree of true stereo.  While it will look 'painted' on the
planet, without more than a surface; seeing Jupiter as a round ball, in
full (livid) color, is most impressive.

Stereography of a moving object like a comet can also have convincing
depth, though it will be on two levels only: a flat comet will appear
suspended against a sky.

>the Mars stereo images I've seen were
>terribly boring... flat rocky desert..
 
Photos of the moon & Mars can be somewhat arid.  But only if taken totally
out of context are they anything less than exciting (I will refrain from
calling into question the soulfullness of any of us).  If you remember the
moon images in 1969, were they exciting?  There are books with lunar
stereos, taken from orbiters, that present them as dry geologic features.
But once you know a little background, these craters are eons old, and the
impacts reveal the strata of the lunar surface, which in turn tells us the
early history of the moon & where it might have come from.  They represent
a new frontier and are extremely interesting.
If the Mars Pathfinder stereos seem boring, just relax and view them for a
while, keeping in mind that this is a virtual tour of another planet.  Go
outside & have a peek at Mars, then look again.  Visit a martian meteorite,
and have another look.  There really is some excitement there, a feeling
like you're in the landscape & could pick up one of those rocks.

Why is a stereo tintype from the 1860s of a young lady more interesting
than a recent stereo portrait?  It is the context, we are feeling like we
could reach out & touch someone who's been gone for almost a century.
Context & explanations are everything in photography.  Otherwise, we're
just like a scanner, inputting images into a computer.
_______________________________________
Peter Abrahams   telscope@xxxxxxxxxx
the history of the telescope, the microscope,
    and the prism binocular


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