The Fotodiox DLX Stretch Adapter allows you to extend the lens from the camera body giving the ability to focus closer than normal as well as correct for any possible back focus the lens may have, in effect this adapter acts like a small built-in bellows. Additionally this adapter has a internal 49mm threaded spot for adding filters to give you further creative control over your image. Our Mamiya 645 adapter is only designed to work with Mamiya 645 manual focus lenses. NOT compatible with Mamiya 645 autofocus lenses as well as Phase ONE XF lenses. Compatible Fujifilm GFX G-Mount Cameras: GFX 50S and 50R Please Note: This is a manual adapter, so lens functions that rely on electronic communication with the camera body (autofocus, AE metering, image stabilization, etc. ) will be disrupted. We state “infinity focus allowed” because our adapters are designed to be universal which can prevent some lenses from focusing to infinity at the infinity mark. Set your camera to “Manual’ or ‘Aperture Priority’ for metering. If camera does not release be sure to enable ‘shoot without lens’ in camera settings. All pictures are for illustration purposes only. Actual product may vary slightly due to ongoing improvements in design.