zero order star test

#579829
Robin Leadbeater
Participant

>A possible test for this could be to check the zero order image of a star without the slit in place.  In this configuration the grating is effectively a mirror so the image should be round. I have not tried this though.

Actually, checking back I see I did run this test. (though only after I had cured the astigmatism.) The test report is attached. 

Cheers

Robin