My pick
- Blackmagic URSA Mini B4 Mount (corrected x1.1)
Other options that I came across (MFT, Sony E, PL)
- KIPON B4 to PL S35 (corrected x2.9)
- Fotodiox Pro B4 to MFT (corrected x1.4)
- IB-E HDx35 B4 to PL (corrected)
- Sony LA-EB1 B4 to E (corrected)
- Multicam B4 to MFT (corrected x1.1)
- MTF B4 to PL (corrected)
- Zhongyi B4 to MFT (corrected x2)
James and Camera adapter
James and Camera is putting great content on B4 optics.
He has tested a lot of B4 lens (with and without corrected adaptors).
He is also selling a B4 adapter to various mount (Sony E, PL…).
Source: James and Camera channel