The removable lens board slides in sideways. It’s not hard to fashion a 3mm thick black plastic board to fit in. I 3D printed a board that takes Mercury Works Universal Camera lens accessories so, once the board is in place, I can mount view camera lenses, Mamiya Press lenses, etc. In theory. This is an elegant, minimal, rangefinder design. As an engineer by training, I really like the design. But, as a portable, casual, camera, the challenges of framing, focus, metering, dealing with the dark slide, the small aperture, and shutter cocking...one might as well go large format, which is what I’m doing. By the way, the native 62mm lens covers 6x7, and 6x9 if you stop down to f11 or smaller aperture.