Photo of Comet 73/P Schwassmann-Wachmann

It is Dave, saves the whole allignment procedure when you want to get a 'quick snap'! Gary PM'd me the same (pretty much) explanation as you have just described.

Dave L,
nice shot too, like Martin said, nice colours!

Seanie: When gary says 30 seconds unguided, what he means is that each individual frame was unguided for 30 seconds. The 70 or so frames were then aligned and stacked in images plus (using the comet nucleus as the reference, giving the same effect as if the entire shot were guided on the comet. Pretty neat huh?

Thats pretty much how I do it also, I did contemplate trying to set the guider on the comet itself, but felt that since it was the first night using it, that it might be abit too much to try on the first go.
Also, the guider instructions states that sharp star points are preferred for accurate tracking, a diffuse cometary nucleus might not do the job.
Has anyone tried auto-guiding on a comet?