Vignette issue

I wondered if anyone here has had the same problem that I'm having and how you may have gotten around it. I'm using a BMD Studio 4K and the lens is Fujinon XA16x8A-xB8. So, many of you already know that I had to get an MTF B4 2/3 to Micro 4/3 adapter just to get them to connect. The texture on that lens is amazing, but as you zoom out, just about 1/2 way back it starts to Vignette and so there is no way to get any sort of wide shot without the use of another camera. So, first question, is anyone aware of a smaller adapter that significantly reduces the vignette (or preferably eliminates it altogether), Or is anyone using a lens that is comparable to the Fujinon, but requires no adapter at all? I'm not at all interested in the little powered ones by Panasonic or Olympus. They look like $350 lenses, and the Fujinon looks like the $7000 lens that it is (or was then anyway). This is not really my expertise so I'm really looking for guidance. I'm really sold on the BMD camera, but seriously there's got to be a better option without breaking the bank, right? Thanks in advance folks.

The MTF Services B4 adapter is designed for a S16 size (12.5x7mm) sensor only, “Although it has a Micro 4/3 mount, this adapter will not cover anything larger than a Super16 size sensor.”. The MTF B4 adapter uses a .86X tel-converter element to expand the smaller image circle, while the BM B4 Mount uses a 1.5X Converter to insure coverage of the larger sensor.

The S16 projected image circle is 14mm, while the BM Studio 4K sensor (13x7.34mm) needs a 15mm projected image circle, so as yiu felt down to the wide side of the zoom, the projected image circle gets smaller, and starts to vignette when it becomes smaller than 15mm.

The Zeiss Super Speed S16 lenses 12mm barely covers the 4K sensor, and the 9.5mm also vignettes. So not all S16 lenses have the same projected image circle size, and while some may cover the larger sensor on the Studio and Micro Studio 4K Cameras, others will vignette, when the image circle becomes smaller than the needed 15mm to cover the slightly larger sensor.

The new Ursa Broadcast Camera would be a better fit for that Fujinon B4 Zoom, and yiu get full Lens control on the camera.
Cheers