High fwhm numbers

[Howardk]

I’m getting fwhm numbers whilst live stacking of 8-9.5

Is this due to me being in altaz with no polar alignment and no tracking?

[admin]

Hi,

well, almost certainly yes... With no tracking then you are going to get little lines rather than point stars, and the length will depend on the length of exposure and how close you are to the celestial pole. If the lines become long enough then SharpCap will refuse to stack because it won't see them as being stars, but if they are fairly short then they will show up as 'stars' with an increased FWHM.

For more accurate diagnosis, it's probably best to share an image of what you have captured - it might be that something else is going on.

cheers,

Robin

[Howardk]

Robin

I meant to say no guiding
The mount in altaz is tracking

[admin]

Hi,

OK, then in that case the stars should not trail out (except in some areas for long exposures where you might see rotation effects at the corners of the frames). Did you save any individual frames that you could share? They would reveal a lot.

cheers,

Robin

[Howardk]

Will save some frames next time