Thanks Allen, I'm going to noodle on this drawing and your previous comments for awhile JA... Allen Daves <allendaves@xxxxxxxxxxxxxx> wrote: Sorry Ja..i got the email just now..after i got your second one..... Answer: Yes the geometry is correct.. j a <ja_777_aj@xxxxxxxxx> wrote: Allen, Here is a new drawing for your consideration. And I would appreciate it if you limited your responce to the 1 question reguarding the drawing The left drawing is of a fixed camera position at 8 times during a single 24 hour revolution of the earth. The right drawing is of a fixed camera position at 8 times during a yearly revolution of the earth about the sun. The camera is setup parrallel to the nightly axis for convienence ( angle does not matter ) and is fixed wrt the earth for all 8 positions in each drawing (any angle change of the camera wrt any axis is due to the earths movement. 1) Do you see anything wrong with the geometry as I have represented it, assuming a HC framework? thanks, JA --------------------------------- Get easy, one-click access to your favorites. Make Yahoo! your homepage. --------------------------------- Never miss a thing. Make Yahoo your homepage.