spectro-aras.com

I have seen so called "flat field imaging gratings" "aberration corrected concave spectrograph flat field gratings".

http://www.horiba.com/us/en/scientific/ ... -gratings/

could these be applied in astronomical use? they seem to be rather fast f# (2.7) so either a focal reducer on an already fast telescope would be required or other extreme measures if a good f# match.

The simplicity of one optical component does sound appealing! Has anyone tried one?

Cheers,
Hamish

Hi Hamish,

The Starlight Xpress spectrograph uses one (not sure if it is this actual one though)
https://www.firstlightoptics.com/starli ... amera.html
https://www.sxccd.com/handbooks/Handboo ... ograph.pdf
I have not seen any serious results from it (There don't seem to be many out there) but from what I have seen it does show severe astigmatism. Not a show stopper but it must decrease sensitivity to some degree and it would not be any good for imaging spectroscopy. Perhaps it might work better with a cylindrical corrector lens like the UVEX ?

Cheers
Robin

EDIT: I see Horiba claim this one is astigmatism free and can be used for imaging so different from the SX one by the looks

Thanks robin. I forgot about the sx.