Quote:
Originally Posted by atalas
Nice work Lee!so,8 sec subs eh.....so the mount wouldn't allow you longer?I would of thought with good polar alignment 2 min would be ok.
Anyway I like what you've been doing with the little cam...very cool.
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Cheers Louie :-)
Eh, the mount might have been able to do better, it depends on the day, as I mentioned in my post to Glen. This is a mount that really need to be guided. It can (and usually does) perform well guided, but definitely not something you want to try serious unguided work with.
I've seen the mount drift 250" in RA over the space of an hour. That's about 0.5" in 8 seconds if my math is correct (it's frequently not!). I'm sampling at 0.93"/px and I consider 0.5" drift in the sub length to be acceptable, but I wouldn't want to go much over. Keep in mind that's just average drift, and doesn't consider any of the little bumps you get when tracking.
By keeping subs at 8secs I was able to get FWHM of < 3" for 696/734 subs. FWHM was as low as 1.7" in some subs.
I hate having blurry data, and I'd rather have more noise, thus the sub length.