autoguiders

[mick pinner]

could those of you that are using autoguiders through a guide scope give me your impressions of the set up you're using, also what software you have tried. thanks

[[1ponders] (Paul)]

Hi Mick.

Just a newb at autoguiding, but FWIW.

Software I'm using K3CCDTOOLS V2, once you get over its little idiosyncrasies its fairly easy, but I found it a frustrating learning curve to start with. Much thanks to Robby for assisting me there.

The only guidescope I've used, is my 102 celestron and that was for piggybacking my 300D. Straight forward enough. Though I did find that guidestar selection played a big part in my success. I now tend to select a moderately bright star (I'm using a ToUcam for my star capture) if possible, keep the brightness up to full and drop the gain to zero. I then start dropping the brightness until the star is still easily visible onscreen but not showing any flaring. For me I found that was the most important aspect, to get as still a stellar image as possible. Once I got that and as long as I didn't walk anywhere around the tripod the guiding graph kept as nice and smooth with only the occasional bump. the same technique works with OAG as well but its much more difficult go find a guidestar without moving away from the object I'm trying to image.

Hopefully in the next week or so I will have my new guidescope plus a set of guiding rings. mainly give me a larger choice in guide star selection. There is a product call the Tau Ceti X-Y finder, that will allow you to use normal mounting rings for the guidescope. I've not tried it or seen it in action but a number of people have mentioned it to me as a very good alternative to guiding rings. http://www.sciencecenter.net/hutech/gd-acc/xyfinder/ Looks interesting but isn't a good cost comparison with guide rings.

the only other thing I'm using is StarMate as interface between laptop and Losmandy drive system.

Everything I have going ATM works like a charm and I'm expecting big improvements once I get all my ordered gear.

FWIW

[Robby]

Hi Mick,
I have a Losmandy G-11 mount (non Gemini), and image through a Celestron C9.25. I use a Celestron ST80 as a guidescope and have found it excellent. I am using a unmodified ToUCam as the guide camera. The guidescope is attached to the Main OTA using Losmandy DR108 rings. These are great as they let me move the guidescope all over the place until I find a guide star.
System works together like this...
* Imaging with C9.25 & Canon300D, mostly with f/6.3 focal reducer.
* Guiding...
-- ToUCam in back of ST80 to PC via USB cable. Never had a problem finding a guidestar yet.
-- PC running K3CCDTools2 in Guide mode issuing LX200 commands for guiding
-- Serial output of PC to LX200 emulator (my star-mate)
-- ST4 output from LX200 emulator controlling mount movement using ST4 signals.

Clear as mud!..!!
Ok the purists out there will see a glaring hole in my system.... Can you guess??
I am imaging with C9.25 at a focal length of 1480mm (f/6.3), and guiding at a focal length of 400mm!! The opposite should be true. However my results are fine and if you think about it, I essentially have a 3pixel error in my image. Even the smallest stars end up coming out at over 5pixels anyway! Atmospheric turbulance will affect image quality way more than this error... Anyway I'm rambling, but hopefully you get am idea of what I use!

Cheers
Rob

[gbeal]

Mick,
I am virtually the same setup as Robby, same camera, guidescope, guidescope rings, and interface between guiding camera and computer, with K3 as well. I use either the ED80 refractor or an old 10" f5 newt for imaging.
Gary