Ok, so "invention" is kind of stretching it, but this little adapter rind I just made works perfectly. My Mokba really is quite a camera when you don't want to drag out the 4x5. But with no way of putting a filter on it, or a lenshood, it wasn't much use to me. I already have a bunch of Series 6 filters for my Super Graphic, and the Series 6 lens hood/filter holder assembly. All I needed was a way to get it on the Mockba. So I whipped up this adapter ring. It's made in 2 pieces, the lens half and the lens hood half. Unlike the Graphics, the lenshood fits inside the adapter ring. And the ring fits over the lens. Then glued the 2 halves together with E6000 glue. It couldn't have been done as a 1-piece because of the stop ledge inside. It took a half dozen or more prototypes till I got a snug fit at both ends. I suppose there's a chance the Graphic hood will vignette the 2 1/4 x 3 1/4 negative. If so I'll dispense with the Graphic hood and just use a flat Series 6 retaining ring to keep the filter in, and design and print another lenshood to fit the assembly. What I really like is that when focusing, turning that little knurled wheel on the camera is no fun. This assembly lets you focus much more easily by just turning using the lenshood instead.