what do you think about these ones?

Soligor:
http://i15.ebayimg.com/02/i/02/94/59/bc_1_b.JPG

Kenko:
http://medfmt.8k.com/bronauxfe3.jpg

Spiratone:
http://members.aol.com/mdolginova/my...ages/fish1.jpg
http://images.auctionworks.com/fullV...auctionworks.c
om/hi/48/48259/2_1872_1c.jpg


I think they're all old generation fisheye adapters, designed to be used on
a normal lens... But I believe they were designed for 35mm and don't know if
they're good on MF/LF too. And what if I use one of these on a wide angle
lens instead a normal one?

Do all of them have series VII mounting ring?


bye