Hi I am now quite proficient in taking star trails and taking time lapse of stars.
I came across this video which puzzles me in its execution; a combi of star trails and time lapse.
http://www.youtube.com/watch?v=eRJysFYWQqo&NR=1
from t=0.00 to 0.04 sec it is strictly time lapse but from t=0.04 sec onwards shows the rotation of the earth.
Care to share how it is done.
another example is
http://www.youtube.com/watch?v=ANAmiuAkyGQ&feature=fvsr
aziz