SmallRig Cage Kit for Sony Alpha 7 III / Alpha 7R III 4198
1 × $169.90 
Metabones Nikon G Lens to Blackmagic 4K Speed Booster XL 0.64x
1 × $922.95 Subtotal: $1,092.85
Optional B4 lens mount with precision optics and spherical aberration correction specifically designed to match the camera’s sensor so you can use your existing B4 HD broadcast lenses.
$599.00
To clear up any potential confusion, this is NOT Sony Alpha, but Alpa of Switzerland. You will most likely be using the Kern Macro Switar 50mm f/1.8 or f/1.9 apochromat lens on this adapter.
