Re: ATM Alt-alt telescope mounts and image rotation - long post

["James Lerch" <jlerch1@tampabay.rr.com>]

Mel, Your too damn smart :)

I've got to paint a little mental image for everyone.

I'm sitting here thinking about what Mel just posted.  Trying to wrap my mind
around the idea Mel just presented...

I happen to be sitting in a swiveling office chair, so basically my butt is
sitting on an Azimuth mount.   Next I extended both hands out in front of me,
and sighted down one arm with my eye.  I'm now using my shoulders to simulate
one of the Alt axis...  Next, if I lean Left/Right about my waist, I can
simulate the other Alt axis...

Now I'm sitting here in my simulated three axis mount <g>, and I imagine where
Mars is going to rise in the East, where it will be as it crosses the zenith,
and where it will set in the West..  I make a mental image of the arc motion
this will create inside my office.  I turn my chair and face south,  Lean to
over to the left, sight down my arm and raise it till I'm near where I expect
Mars to rise.  Now I attempt to 'track' Mars without rotating my butt in
Azimuth.  Yup, no problem, but yes, there will be significant field rotation
over the course of the night.

I repeat the above experiment, but this time I use my foot to 'De-rotate' my
view.  OH YEA, that will work!  Interestingly, the rotation in azimuth, if I
start with my knees pointing south, moves my knees towards the east.  If I
'track and de-rotate' the object across 'the sky' it appears I'm going to rotate
about a 1/4 turn or so..  Very interesting <g>

Now, if anyone had seen me doing this, I'd be rather embarrassed as it might
look like I'm performing some weird type of Prayer exercise.  However, I can
take comfort in the knowledge that at least a 'Few' people that read this, will
repeat my simulated experiment <G>

Like I said Mel, your too damn smart!

BTW, how long until Scope.exe can support this type of mount and how will we
implement it? <g>  Will we need to change the handpad config to control all
three axis drives?  (maybe two more buttons and a 5th control line?)  This would
be so much easier if our laptops came with TWO printer ports :)

Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and coating site)