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Okay my views on autoguiding is expensive - its kinda right, but I've pushed my gear to the limit and it works - on a real budget.
I use a Celestron CG5 mount to carry a C9.25 + 80MM Meg - which is quite heavy. This burdens the mount to about 15 - 16kgs, right at or over its intended maximum carrying capacity for visual, let alone astrophography. In its favour its on a very sturdy permanent pier, well balanced and pretty neatly polar aligned. So the tracking is pretty good to start with for visual. If I focus on a star and come back 3 hours later its moved about 1/3 of the eyepiece out of position - so its probably less than an arc minute off the SCP. Also its all housed in an astrolab - so wind, dew and the elements are kept off my gear which must help its performance.
I simply made a 6 pin connector cable of the right length, bought a ShoeString Parallel Port adapter (wish now I went the USB version that has automatic line pull down on start-up), attached a DSI via USB to my PC and generally use PHD to autoguide.
I find PHD very simple to use and tracking seems way better than I have expected. So far I haven't done longer than 10 minute shots, but I'm planning to do a few long duration shots just to get a feel for the limits of what my platform can do. My main capture camera is a Canon 400D (with filters not removed, and no external / 3rd party cooling), so long shots are likely to be noisy.
The point is a CG5 is a really questionable platform for longer duration astrophotography, let alone when it is loaded to or past its normal visual carrying capacity. Yet the results - well I'm estactic to say the least. PHD is making few corrections and 10 - 15 minute shots look fine, at least from a tracking accuracy - true colour capture is something I'll want to verify next!
To me this is not an outrageous expense:
1. Goto mount, hand controller slaved to PC via cable I build and serial port adapter, using CDC for goto control $1,300
2. Meg - second hand $400
3. Meg mounting rings, saddle plate, screws $150
3. DSI - second hand $350
3. Shoestring adapters $95
4. Cabling, connectors, serial adapters, multi-meters, crimping tools - $90
5. PHD and CDC - free
So its cost me about $1,080 to add goto to an existing mount + OTA set-up, including the second OTA. I find this pretty awesome.
I'd love to be using a better mount and capture camera, but above an eq6 I'm looking in the $5,000 - $6,000 for a capable goto mount and you could say +/- 50% of that again if you went the S-BIG path for capture and/or autoguiding. For now all I really want is more precise goto's - and I'll start playing with T-Point to see if I can make my CG5 even more accurate than you'd otherwise expect.
That will have to wait a bit, cause right now for what I've spent I have a solid enough base to learn on.
So in my case at least is auto-guiding really all that expensive?
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