Hi Brian
Thanks for your input.
Answers to your questions
1. elongation is same length regardless of exposure time
2. elongation is one direction only. When i turn off PHD guiding the elongations can be seen more clearly in RA only
3. I don't see any field rotation or distortion across the field of view for example stars elongating out at an angle at the edges, it just seems to be constant across the image.
If the skies are clear Monday night i will do another polar alignment. I always get confused with my direction when doing a polar alignment but get there in the end.
I'll report back when skies are favorable
Regards
Carl
Quote:
Originally Posted by tempestwizz
I'd check the direction of elongation also. ie is it in the Dec plane or the RA plane or flexure if in line with guide-scope gravity. That would give a clue what to look for most.
Is the extent of elongation related to length of exposure? If not, it could be hysteresis in guiding.
What do you get with no guiding? RA drift, Dec Drift, or both? Better to look near Zenith when checking this.
But, since you notice effective rotation when pointing South towards Tuc47, it indicates your polar alignment is off.
In defining exactly what the problem is, you will probably identify a solution.
Cheers,
Brian
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