Quote:
Originally Posted by DiscoDuck
Presumably for those subs with elongation your guiding graph must be worse than the one you attached above, i.e. worse than 0.45" total RMS? What sort of FWHM are you getting?
Unless there's some sort of differential flexure (though I see you're using an OAG, right?)??
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From my reply below
Quote:
Originally Posted by Slawomir
Hi Lee,
When things are not so great the RMS is around 0.7-0.8" and it causes noticable star elongation at 1.33"/px. Would like to have longer exposures with autoguider to reduce effects of seeing, but then moment to moment RA tracking errors of my mount can be too significant and need more frequent correcions. So I found 1.5 sec corrections to be a fine spot with my mount most of the time.
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Quote:
Originally Posted by Atmos
TSX said I was ~18 seconds away from SCP so not too bad :-)
My understanding is that it is only the movement of the gears that is of any importance and this shouldn't happen through movement. Meaning that you can move the telescope around freely when the clutches and lose and it should have not effect.
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Thanks Colin, I did not know that.
I feel my mixed results with PEC are because of:
1. My methodology has flaws
2. The RA errors vary from cycle to cycle in my mount thus it is impossible to have a well fitted single PE curve, even if PE curve is an average of several runs. So occasionally and inevitably PE corrections go the wrong way - enough to spoil a sub.