Parachute Viewing?

(Roger Emerick) wrote in message . com...
I do not know anything about telescopes. For a project I am working
on, I would like to view the descent of a 50ft diameter parachute
dropped from 10,000 ft, in the daylight. Can you tell me what the
best kind of telescope (and tripod) would be for this effort? I would
like to find an inexpensive one, perhaps on E-Bay. Thank you. Roger

I fly rockets that use such parachutes and at 10K feet, you could see
it with the naked eye easily. If you wanted to see what was going on
witht he chute, a pair of 10X50 binoculars would be best--better than
a telescope. Just make sure you have a comfortable chair that you can
sit back in. You could even lay down on the ground. I do this often
with flights much higher (like 30K feet) and can easily track such an
object.

CJ

"CJ" wrote in message
om...
(Roger Emerick) wrote in message
. com...
I do not know anything about telescopes. For a project I am working
on, I would like to view the descent of a 50ft diameter parachute
dropped from 10,000 ft, in the daylight. Can you tell me what the
best kind of telescope (and tripod) would be for this effort? I would
like to find an inexpensive one, perhaps on E-Bay. Thank you. Roger

I fly rockets that use such parachutes and at 10K feet, you could see
it with the naked eye easily. If you wanted to see what was going on
witht he chute, a pair of 10X50 binoculars would be best--better than
a telescope. Just make sure you have a comfortable chair that you can
sit back in. You could even lay down on the ground. I do this often
with flights much higher (like 30K feet) and can easily track such an
object.
Yes.
It is worth working out the 'angles' involved. The old 'shooters' rule of
thumb, is that 1" is 1 arc minute at 100 yards. This is about the limit of
normal good sight. At 10000 feet (33 times as far), an object 33" across,
will subtend the same angle, and should just about be visible, depending on
the background. I can confirm, that it is usually _just_ possible to see a
person as they jump from a plane at these sorts of height, before the chute
opens. This depends a lot on the sky at the time. Once the chute opens, the
angle of the target, rises to about 18 arc minutes (corresponding to about
the size of a car wheel at 100 yards). If you cannot see this 'naked eye',
then you are not fit to drive...
As said above, a pair of binoculars makes a much nicer way of looking at
such objects than a scope (lie back in a reclining chair), since it is
relatively easy to keep the object in view, and re-aquire it as necessary.
In the *10 binoculars mentioned (about as high magnification as it will be
comfortable to use on a 'moving' target), the parachute will be large enough
to see very significant detail. I have used a pair of the Canon IS 18*
'image stabilised' binoculars to track a parachutist doing a relatively long
freefall descent, and these proved very good indeed, allowing the higher
magnification, while still being stable.

Best Wishes