Autoguiding and Autostarsuite

[JohnH]

I have just attempted my first autoguiding session. Can someone confirm what I believe to be true - autostarsuite (with the standard firmware in the autostar anyway) will only apply corrections to RA. No DEC corrections are applied. I believe this because the guide star kept drifting south in my sessions and no correction was applied. When I realised what was going on I switched to GuideDog and was able to get better tracking with DEC corrections on though I did lose lock after 30 mins or so. Obviously my polar alignment was not good. However I did manage to get some 5 min shots with much, much less trailing than I would have had before so it is a promisisng start. I have still not found a reliable method of getting a good polar alignment grrr.

[Robby]

Autostar should correct in DEC. I have successfully autoguided with AutostarSuite and a DSI. But it is not easy, and you are very limited.
But actually you should not need to do any DEC adjustments if you are acurately polar aligned, as DEC adjustmest => field rotation drift.
Spend time to get acurately polar aligned using the Drift method, so you don't need DEC corrections when autoguiding. Your images will love you for it !!
Cheers

[JohnH]

Robby,

I believe we are both correct - I have an ETX90 which you cannot autoguide in Alt/Az mode (unless you patch the firmware first which I have not done - yet). I believe this restriction is not present for the bigger Meade Scopes. My assumtion, the one I was looking to confirm, is that no Alt/Az = No Dec corrections.

I absolutely take you point about polar alignment - I simply have to nail this somehow but I have never got it right reliably. My problem is I am north of Sydney and have only a partial view to the S from my backyard, I am therefore looking at the SCP being pretty much on my "horizon" and in the worst light pollution. I therefore misidentify Sigma Octans quite often, I would love to get to a star party soon and work with some experianced hands to sort this out....in the mean time drift method via the LPI seems feasable.