Quote:
Originally Posted by codemonkey
0.92" RMS guiding is pretty poor imo. If it was peak to peak that would be what I'd consider good guiding. If I had 0.92" RMS on my EQ6 I would consider it to be behaving poorly and would have been seeking the cause so as to fix it.
With my Avalon Linear I'm usually around 0.5 - 0.6" RMS when pointing further towards dec 0, typically where RA guiding gets worse on any mount. Often the peak to peak is below my imaging scale (1.12"/px).
Now whether that "poor" guiding is truly poor all comes down to your imaging scale. For me, I know that would be doing bad things to my images. On a wide field system with lower resolution? Maybe not.
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Quote:
Originally Posted by Slawomir
I usually get around 0.6" RMS on my AZ-EQ6 (4" doublet, 570 mm fl, 1.33 arcsec per pixel, 3 nm filters) and such performance results in slightly elongated stars. Occasionally tracking error gets as low as 0.4" RMS and then I get perfectly round nice stars. Unfortunately, sometimes tracking gets worse, and subs with more than 0.8" RMS need to be thrown out.
I have been looking at future upgrades, including SX active optics, MDA encoder and also a more expensive mount, including MYT and Mach1. If new G11 consistently performs better than my current mount, then that would be truly great news and I would be seriously interested, after collecting sufficient funds...
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We must not confuse RMS
guide errors with RMS
tracking errors, there is a huuuge difference.
If a mount "tracks" with RMS errors under an arc sec that's absolutely amazing...if a mount "guides" with RMS errors under an arc sec that may in fact not be good enough for many applications.
Eg. My NJP "guides" with errors of around +/- 0.3" but the total unguided "tracking" error is closer to 3 arc sec or 10X worse.
Mike