Re: ATM 100% illumination and secondary sizing

["David Moorhouse" <climber@world-net.co.nz>]

Thanks Joe and everyone, there seems to be a feeling from everyone who has
replied to my secondary sizing question that the larger mirror is better.
Thanks to you all for helping to validate what I had thought was the right
way to go, as I wasn't 100% sure before.

Dave Moorhouse

----- Original Message -----
From: "Joe Curran" <jcurran@asymtek.com>
To: "'David Moorhouse'" <climber@world-net.co.nz>
Sent: Saturday, March 17, 2001 8:54 AM
Subject: RE: ATM 100% illumination and secondary sizing


> It made a BIG difference for my 8 inch F6.  The original focuser had the
> image plane 4.5 inches above the surface of the tube.  I bought a JMI low
> profile focuser to bring the image plane down to 2.5 inches above the
tube.
> Now, this required moving the entire focuser assembly and secondary about
> 2.125 inches farther toward the end of the tube.  End result?  I went from
a
> non-existent 100% illumination zone to .25 inches.  With it, planetary
> detail is >much< better, and I was even able to see the dust lane of M31 -
> not just the central bulge.  All from light polluted Carlsbad, CA.
>