Quote:
Originally Posted by LewisM
That is NOT a happy GPD2. Never seen a curve anything near that with mine - I did see it with an HEQ5 once though!
Last time out, I had an RMS of 0.07 (see: http://www.iceinspace.com.au/forum/s...d.php?t=126628), varying by VERY little over a 10 minute period. That was with a 7.2kg rig. I have since readjusted Dec (was backlash), so next time out, fingers crossed.
I am going to convince myself the GPD2 can do it
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I thought that PE curve looked pretty good - reasonably smooth and consistent. Not much published data on the mount, but found one other source suggesting 25 arcsec PE, which would be fairly similar. The point that I was making is that, apart from lower load rating, small mounts have a lot more PE to guide out than big mounts - and there is always a little bit left after guiding. Reducing PE is one of the main reasons why top end mounts have extra large worm wheels and bearings.
If you are measuring 0.07RMS (I presume that is in guide pixels), and guessing that your guide scope/cam has pixels of about 6 arcsec, your guiding is within about 0.4 arcsec RMS. That is pretty good - provided that you do not have guide settings such that the guide graph is flat, but at the expense of big stars. If your mount can reliably keep within 0.4 arcsec RMS, it will do the job.