FotodioX Hasselblad V-Mount Lens to Hasselblad X-Mount Camera Adapter

I would suggest dropping crop factor. Calculating what the Angle of View is for a format you are not using does not make sense if you do it all the time. It is far better to learn what the mm lengths are for normal-wide-tele for the sensor you are using. Since the mm of a lens does not physically, change you can then tell at a glance what the perspective will be. But to answer your question, since you are going from a larger film format 63 x 63mm, to a smaller digital format, 43.8 x 32.9mm, the perspective change, or crop factor is 1.4. Lens vignetting will depend on the lens. The wider you go the greater the chance. However, we do not know offhand of any lens that would vignette with this set up. Finally, as in all lens mounts that are not screw-in, there is a catch you must release in order to dismount the lens.