From: Milton Aupperle <milton@outcastsoft.com>
Date: November 10, 2005 4:37:39 PM MST
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] Re: Camera for guiding
Hi David;
On 9-Nov-05, at 10:03 PM, David Illig wrote:
You made one remark earlier in this thread with which I take issue. You wrote "The entire
'Mac Astro Guiding Market' isn't more than 100 users..." and I know it's much bigger than
that. I know that because I know three Mac astronomers within 20 miles of me who are
interested in autoguiding, and I know another in New Jersey. That's five, including me. I
also know it because of the amazing e-mail response to my little page about "The
Macintosh in Amateur Astronomy" at <http://www.davidillig.com/astromac.shtml>. This
is a personal web site that was intended mainly for distant friends and family, but it
started getting hits -- and I started getting e-mails -- by the hundreds from Mac users
who were grateful to learn that the Mac can be used in amateur astronomy, as well as from
Windows users who said, practically in unison, "That's it, I'm switching. I've been fed up
with Windows for a long time, but I didn't know the Mac could be used in astronomy."
My number of Guiding Users could be off to some degree - it's an estimate based on the number of people I see that subscribe to various Astro Mac User Lists, from talking to other Mac Astro Software developers and from talking to FW camera manufacturers.
For example there are 51 in the Astro IIDC group, 202 in Equinox group, 79 in MacAstronomer, 95 on the iCCD list and 359 on the AstroMac Topica list subscribers. That doesn't account for any duplication of people on multiple lists nor what their interest levels are, but it sure would seem to me to indicate that their are not a large number of people doing Mac based astronomy imaging in total.
And how many of those say 359 have the equipment, time and patience to set up a scope that is polar aligned, has a guide scope, have a FireWire camera for guiding and want to do it?
So I'm not disputing that many people are interested from your web site hits, but probably lots are not going to need guiding.
Now, one question. What do you mean by "...has preliminary support for Auto Guiding on
stars..." What else is needed -- given that I have the necessary hardware (Keyspan Serial
Adapter) and cables for telescope control?
Well it has to be an LX200 or compatible command set mount, we aren't supporting Temma nor Celestron mounts. Celestron doens't support slewing while tracking just GoTo and Temma is just plain "weird" to work with.
Preliminary means it has not been extensively tested and the bulk of the testing so far has been with my Isopotical USB Box on my Hacked EQ3 mount for RA tracking. In fact most of my own long term testing (say a few hours at a time) has been with tracking sunspots ( with inversion check marked to make them "white" and the sun disk black) during the day time at Prime focus (1540mm) with a Unibrain mono camera.
Finding people who were willing to be good constructive alpha / beta testers testers is not an easy thing, especially since the weather is always a factor (hard to be precise tracking with +/- 10 arc seconds of turbulence motion) and it's a night time activity.
Luckily in the current Alpha program, Raoul Schlesser stepped up and over a two week period we got the declination fine tuned and working for LX200 and SkySensor PC 2000 Vixen mounts, including sub pixel tracking to +/- 0.1 pixels. At prime focus with a Unibrain camera, that's roughly +/- 0.15 arc seconds of accuracy - assuming that turbulence is not too excessive and the Alpha now allows you to specify how much delta pixel motion to wait before it requires correction so that it isn't overworking your drive motors with more correction than is necessary for the turbulence conditions.
Hope That Helps..
Milton J. Aupperle
President
ASC - Aupperle Services and Contracting
Mac Software (Drivers, Components and Application) Specialist
#1005 - 815 14th Avenue. S.W.
Calgary Alberta Canada T2R0N5
1-(403)-229-9456
www.outcastsoft.com