Maybe for a really long time, we've been going about trying to get manual control over Instax Film totally wrong. Instead of trying to hack medium format cameras and camera backs to accommodate the film, why haven't we tried hacking the cameras available to start with? Well actually, the folks over at Camera Film Photo have been for a while now.
Indeed, a Fujifilm Instax Wide 300 camera can be hacked to take a Schneider 65mm f5. 6 lens and apparently even other lenses. The lens has both the shutter speed and aperture control on it just like some of the higher end medium format cameras and pretty much all large format cameras. . thephoblographer.com