Yes, most Canon EF lenses (full frame not APS-C) will work on Fujifilm GF mount cameras like the Fuji GFX100 mkII. And yes, this adapter SHOULD allow full manual control. We say “should” because there are probably some lenses we haven’t tried that don’t work, so we suggest testing any combo before your shoot. But for the most part, if it’s a modern Canon EF lens, you should be good to go.