Having now indoctrinated Drift Alignment into my photo work since I started using the
autoguider, I have to strongly agree. As a matter of fact, I now just do a very quick
2 star (polaris plus one other), with my LXD650 mount just to get it in the ballpark
and then quickly install the (2x) barlow and the 9mm reticle and go right to a star
near the meridian for the azimuth drift align adjustment. I have not had to redo a
latitude adjustment in over a month since I always set up in the same position on the
same 3 blocks in my driveway and make sure head is level. I checked it just last week
and it stayed on the line for 5 min.

My PEC is good out to 1 sec. integration, which, with my 90mm guidescope and decent
(not great) seeing, gets me into mag. 8 guidestars. It could be improved, but just
haven't taken the time.

m.

Michael Hart wrote:

> Astro-Barbi has reminded me to respond more promptly to those that have
> sent personal e-mails to me. I am way behind do to several astronomy
> projects and endeavors- many of the projects are behind-the-scenes in nature.
> I'll try to answer all as quickly as I can. Astro-Barbie has also insisted I make
> amends. From time to time, I will post some of my field notes which are on
> topic and of potential interest to members of Mapug.
>
> My colleague and I returned from a trip to South Florida finalizing a remote
> controlled observatory. The AP-7 CCD camera and Paramount are the
> workhorses at this site. Those two items alone are close to $20,000 US.
> To put things in perspective, neither myself or my colleague have a financial
> interest in this site, however, I have been invited to use the equipment for
> scientific research works. I will likely do some semi-serious research
> remotely from my home. I am both pleased and honored to be allowed
> observatory time on this fine equipment.
>
> I had the opportunity to spend an evening with the designer of the Paramount
> using his 22" Byers Research mount. Yes, a 22" worm-wheel. I have seen
> and used much smaller Byers mounts at costs of over $50,000 US. We did
> a bit of planetary imaging under the steady South Florida skies. His facility
> looks like a small star party with many scopes running- absent observers.
> Most are on high-end mounts, including several Paramounts. We discussed
> CCD imaging techniques and compared CCD images. Here, one can compare
> SCT's, Mak's, and refractors on good mounts and good-excellent seeing.
>
> The Paramount (at close to $10,000 US) uses stepper motors for up to 2
> degrees per second and a cogged belt drive for the worms which are spring
> loaded on rails to remove lash. Classic observatory mounts often do not use
> spring loading, however, I'm seeing this on more and more recent mid to high-
> end amateur mounts. Many of you know the LX-200 uses a spring loaded
> worm carriage. The paramount is designed for permanent mounting.
>
> So, after having personal access to all this great equipment, I returned home
> to my tweaked and slightly modified 12" LX-200. Those that are new to this
> list can find details to various mods and tweaks on Doc G's web site and
> Ed Stewart's Topical Archives. I must say I was not disappointed with the
> LX-200 performance. Of course, the LX-200 isn't a Paramount just as a
> Paramount isn't a professional observatory mount, however, if one avoids
> bumping the scope or mount (even lightly), the LX-200 works amazingly
> well. Collimation of my 12" was dead-on (it usually is) and the smart drive
> programmed months ago under good seeing was working very well. So well
> that I decided to take a 10 minute guided (3 second corrections) and unguided
> images to see how well the mount tracked. Both unbinned CCD images using
> 9 micron pixels were virtually identical at 2.5 arc-second FWHM (Full Width
> Half Maximum) stellar in both x and y axis.
>
> Many astrophotographers insist on constant guiding and question the notion
> of leaving the scope for several minutes to relax while manually guiding.
> However, I have found that under good seeing, a well aligned mount and
> programmed PEC will allow several minutes of no guiding corrections. I
> must say that under 1-2 arc-second seeing, constant guiding of a small
> amateur mount produces a bit tighter stars, but not much so.
>
> I believe serious observing and most astophotography on mass produced
> amateur mounts will benefit from excellent polar alignment and excellent
> PEC programming. Drift alignment is one of the best methods if not the
> best method to achieve excellent polar alignment. Highly recommended.
>
> --
> Michael Hart
> Husen Observatory

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