I googled 'Canon Ricoh adaptor' and those popped up so I was asking if those were what you were after (I get 4 pictures showing adapters) , especially as they had a screw thread. If they are not what you need, then OK.Do the Ricoh lenses have the M42 screw mount? If so I a sure there are adapters for that.
Mike I'm completely new to photography so seeing those adaptors meant nothing to me as I haven't a clue which one I would need!
I was in Doncaster when I posted the thread from my Nokia phone having just bought the Ricoh converter off a market stallholder (although the stallholder was a photographer by trade) but I literally bought it blind & I just went by instinct because it looked so well made & heavy!!
Anyway since getting home I have found that it screws directly into two of my camera lenses & the results are pretty impressive.
Thanks for replying Mike & apologies if I sounded off at you it wasn't intentional. ;-)
Mick
Stock photo of the Ricoh lens