Hello,

so yes it is important !

if you use a guidescope you are a canditate for field rotation :

the problem :

increases when you go toward polaris, for example M82 is a pain if you want
to autoguide without a nice polar alignement

increases when your guidescope aimes far away from the image field.

I would strongly encourage you to be within

20 arcmin from the pole, for imaging around DEC 0

10 arcmin for DEC45

5 min for DEC60

and aim you guidescope near the image field ...

astroart is a really good program to do the job, use the shortest focal you
can , for ex with a reducer for webcams.

There are some calculation here :

http://pagesperso-orange.fr/mesxxi.durand/tolerances.htmlhttp://pagesperso-orang\
e.fr/mesxxi.durand/tolerances.html


Vinz