From: Peter Tattersall <ptatters@zerobyzero.ca>

Date: July 7, 2007 11:22:57 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] autoguiding software

On 7-Jul-07, at 12:45 AM, centurion40tim wrote:

It's been a while since I've used my AstroIIDC. - Became obsessed with shooting DSOs and

bought a meade DSI. I was forced to buy an old PC to run it (aaarghh painful).  Good

success but all unguided and I am ready to make the jump.

I want to use my Unibrain webcam and my mac to guide. Is there any cheap autoguiding

software out there for my mac? (g-3 imac 500 mhz 512 ram 10.3). The webcam should be

great but I need to send guide commands to my CG-5 mount.

Celestron 9.25 ASGT- has autoguide port/ unibrain webcam/ ASTROIIDC/ DSI color for

main imager - probably/

Orion 80mm short tube enroute as guidescope

thanks for any comments

TimH in Arizona

Since you are writing to an AstroIIDC list and have both AstroIIDC and a suitable camera in the Unibrain, go for the obvious choice - AstroIIDC! You will need to pick up GPUSB from Shoestring Astronomy to control the mount through an ST4 port.

Actually, since you have both a DSI and a Unibrain you are not starved for choice. For the DSI you could use Stark Labs' PHD for software and Shoestring Astronomy's GPUSB to connect to your ST4 port. The Unibrain may not even be an option with PHD (which has drivers for the Starfish, DSI series, SBIG and Imaging Source firewire cameras [should drive Unibrain, but no guarantee]), but AstroIIDC gets you to 1 second exposures on the Unibrain, while PHD will get you up to 10 seconds on the DSI.

I've been trying a DSI Pro with PHD on a G4 iBook [10.4.10] with an Orion Express (80 mm f/6) as a guidescope for the past couple of weeks. I have the Express mounted on the main scope using a 1/4-20 screw which makes the position almost impossible to adjust for a suitable guidestar. Since using  PHD I haven't had to make any adjustments -- there has always been something useable in the frame if I went deep enough. On the other hand, the main scope is only a FLT-110 and I'm imaging under smoggy city skies, which limits the initial choice of objects anyway.

Stark Labs' Nebulosity will also allow you to image with the DSI on the Mac - you can ditch the PC! However, for any image processing you really should consider an upgrade of your laptop - a 500 MHz G3 is painfully slow. My iBook runs at 1.2 GHz in the observatory, and I even find that somewhat painful, to the extent I save the images for processing later on a desktop machine. On the other hand, I'm imaging with a DSLR so the images are much larger than with either the Unibrain or the DSI. Unless you want to go to a DSLR though, my suggestion for the moment would be to guide with AstroIIDC and the Unibrain and use Nebulosity with the DSI for your deep-sky objects.

Peter Tattersall

http://www.zerobyzero.ca/Starstruck/

Liberty is, to the lowest rank of every nation, little more that the choice of working or starving.

 -- Samuel Johnson