Should I see this after polar alignment?

[BrendanC]

Hi,

So I've been getting to grips with polar alignment with Sharpcap.

Tonight, I got the best yet, really close to perfect.

Then, out of curiosity, I set my scope to the home position, took a shot, plate solved it, and sent the result to Stellarium. This is what I saw:

Polaris is only just about in the frame (the red outline).

Does this say anything about my polar alignment being good/bad? Or is it more about how I've set the home position? Or doesn't it really matter as long as I align my stars properly?

Also, related to polar alignment: if I slew horizontally, and the star I'm looking at on my screen goes across at a slight, non-horizontal angle (same for vertical - slewing vertically and star deviates from the vertical line), does this imply anything about my alignment, or more about whether the mount is level?

Thanks, Brendan

[vlaiv]

18 minutes ago, BrendanC said:

Polaris is only just about in the frame (the red outline).

Does this say anything about my polar alignment being good/bad? Or is it more about how I've set the home position? Or doesn't it really matter as long as I align my stars properly?

It tells you mostly that your OTA is not parallel with your RA axis.

This can happen regardless of polar alignment and most notably it is called cone error. You seem to have a bit of that (scope is pointing upwards / downwards of where it is supposed to point when in home position).

20 minutes ago, BrendanC said:

Also, related to polar alignment: if I slew horizontally, and the star I'm looking at on my screen goes across at a slight, non-horizontal angle (same for vertical - slewing vertically and star deviates from the vertical line), does this imply anything about my alignment, or more about whether the mount is level?

Again not related to polar alignment - that is related to orientation of your camera.

Rotate camera in focuser and you will change direction of star motion when you slew in RA or in DEC direction.

[MarkAR]

Depends on how wide your field of view is. Polaris is just off true north so will be to the side of your image.

Also as @vlaiv says, scope and mount may not be in alignment.

Edited July 30, 2020 by MarkAR

[BrendanC]

Thanks!