Further to many requests, Jérôme Frasson has written a simplified guide (3 pages) on optical diffraction gratings and spectroscopic caps for cameras: how to get them, how to fix them, how to use them.
PDF file available on the «Researches in spectroscopy» page“.
![](https://www.ufo-science.com/wp-content/uploads/2014/03/guide_spectro_ufo-science660.jpg)