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Sorry guys...caught up rebuilding an observatory!
The CD has about 600 l/mm (equivalent) (PAS, Chapter 5)
They recommend using it at a grazing angle of around 3 degrees, with the camera lens (50mm fl) almost touching the surface of the disk. Focused on infinity.
When the CD is used with a slit - the camera should be focused on the slit.
EDIT: Should add that the 2nd order spectrum sits about 20 degrees from the surface (based on 3 degree incoming); 1st order about 40 degrees.
Last edited by Merlin66; 12-05-2011 at 05:56 PM.
Reason: Info added
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