Thanks Pauly,
This is a vibrating adapter, the GG is a condenser (Fresnel lens) from a Nikon F3 type D focusing screen (almost any type including D will do since you only need the condenser) I took apart the focusing screen and kept the condenser, next I ground it with 9 micron grit. The condenser improve brightness in the corners of the screen and provide even illumination, resulting in less vignetting.

Thanks!

Thanks Elholandes! Appreciate your comments.

Thanks Andrew!
I use a Canon FD 50mm f1.4 and 28mm f2.8.

Thanks Daniel!
That's very kind of you.

Thanks!

Pour ne pas voir le grain de la lentille et éliminée toute poussière. Oui il vibre tout le temps. (désolé si la réponse est tardive... je n'avais pas vue ce commentaire)

Thanks Dominic!

BTO - Bachman Turner Overdrive

Thanks Max! only some CC in CS3 premiere.