Got a chance to check out the SLR Magic Anamorphot Adapter on my Sigma 30mm 1.4. At 4k the crop and shooting at 2.0 is just enough to allow this lens to be usable without vignetting. Will definitely be placing on order in for one of these!
Camera: Panasonic GH4
Profile: CineV 0'd out
Adapter: Metabones Speedbooster XL .64
Lens: Sigma 30mm 1.4