P3D Re: lunar hyper-stereo?

[Tom Hubin <thubin@xxxxxxxxx>]

Andy Beals wrote:
> 
> Has anyone taken a "simultaneous" [within minutes] hyper of the moon from
> coast to coast?  This would put your baseline [from the lower 48] at about
> 1/90th of the total distance, but it may still prove interesting.
> 
> Has this been done? Before?  I'm aware of the old stereoview [have the Holmes
> card] but I forget the details ... and the image wasn't all that detailed.

Hello,

I considered doing this two years ago. I worked out the math but I do
not have a long focal length lens or a telescope. The way to do it is to
shoot the moon at moonrise then again at moonset on the same night. One
camera means same magnification for both shots. The moon subtends about
0.5 degrees. A 2000mm focal length lens will produce a 17.4mm diameter
image on your film. Try a local astronomy club for a telescope that can
accomodate a camera.   

This large an image may require a long exposure unless you have a huge
lens diameter. The moon travels its own diameter in about 130 seconds as
I recall. You will need to track the moon while shooting if you expose
more than one second or so. You ought to track the moon while shooting
if you expose more than 0.1 seconds. 

Tom Hubin
thubin@xxxxxxxxx



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End of PHOTO-3D Digest 3293
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