I'm making a Medium format (645) DIY technical camera. I intend to use Hasselblad/P67 lenses on it that I mount onto a Hasselblad (or pentax) to Mamiya adapter (the adapter is secured to the camera). My problem is the lack of shutter. I know you guys make petzvals work so I thought I would ask here what the best work around is. I would prefer to do this at the mount so that I can still use my lens on my other bodies.