
to have no star trails use the rule of 600 so 600/focal length so for 400 it is 600/400 1.5 seconds, for 24 mm it is 25 seconds, 20 mm you can go 30 seconds.
I see... that's why coz I used a 12mm at 30seconds...no wonder I did not get any startrail hehe
now to get anything at 400mm...since you can only do 1.5sec you use very high ISO?