tracking variables

[Fieldsy]

Hi all if u have a great night shooting with total error @0.8  how can the next night same target nothing changed can I be getting 1.8 total error ?

[Dr_Ju_ju]

Bad 'seeing', i.e. the air mass is moving between your scope and the target, making the target shimmer.... 

[michael8554]

Polar Alignment

Balance

Atmospheric conditions

Differential Flexture in that very wobbly guidescope mount.

Michael

[MarkAR]

If you're on grass then the hot dry day can cause ground shrinkage moving your scope off PA.

[Adam J]

4 hours ago, Fieldsy said:

Hi all if u have a great night shooting with total error @0.8  how can the next night same target nothing changed can I be getting 1.8 total error

It really is just seeing.

Some nights I get 0.5 on my AZEQ6 GT and other nights I get 1.2 on the very worse nights even higher. Its one of the reasons people say that going to less than 1 arcsecond per pixel in the UK is not worth it most of the time.

The trick is to not be tempted to keep making changes as all you are doing is chasing the seeing and you might even end up making things worse. If you have some settings that worked well once then stick with them and have faith that its probably seeing.

Adam