Well the general rule of thumb as you have heard is double the aperture in mm - so 400x for the 8". But in light polluted skies on a day to day basis I dont think its worth going past 200x. When the seeing is good then you might push it towards the scopes limit.The highest magnification I purchased was 170x, I will go bigger one day (either via a barlow or shorter focal length or both
) but right now I dont think I need it.
As for the exact power touse.. Im not sure if this is correct so someone feel free to jump in.Jupiter's
angular size is typically between 30 and 45 arcseconds, so even at 100x it will appear to be at least 3000 arcseconds or .8 degrees... hmm that seems a little big.. as I said Im not sure if thats right
