This has cropped up a few times in the comments and in various user groups so I thought I would go through what you need to do to use a B4 2/3″ lens with the FX9’s S16 2K scan mode.

Not all B4 2/3″ lenses will directly cover the FX9’s Super 16mm sized 2K scan mode as 2/3″ is smaller than S16. 2/3″ lenses are designed to cover 8.8 x 6.6mm and S16 is 12.5 x 7mm. Some lenses might just about cover this as is, with minor vignetting, but most won’t.

The Sony LA-EB1 includes an optical expander that compensates for this (I think it’s about a 1.35x). With the LA-EB1 all B4 2/3″ lenses should work without vignetting and in addition when an ALAC compatible lens is connected to the LA-EB1 the camera will support the ALAC function which reduces many of the aberrations typically seen with B4 lenses. The LA-EB1 needs a power feed (14.4v) to work correctly and to power the lens. It is supplied with a 4 pin hirose cable that is designed to be plugged into the 4 pin hirose power socket on the XDCA-FX9. This also provides the record trigger signal to the camera. If you don’t have an XDCA-FX9 then you will need to source a 4 pin hirose to D-Tap or similar power cable.

If you have a mount adapter that does not have any optical expansion such as the cheaper MTF B4 to E-Mount adapter (MTB4SEM approx $400), if the lens has a 2x extender you can use the lenses extender if the lens doesn’t cover without it. The more expensive MTF MTB4SEMP (approx $1,200) includes an optical expander and with this adapter all B4 lenses should cover the S16 area without needing to use the lenses extender. To get the zoom servo working you will need an adapter that can provide 12v to the lenses 12pin connector.

Whatever lens or adapter you choose, the lens needs to be an HD lens. The better the lens the better the end result, I know that may seem obvious but when you are using either an adapter with an included optical expander or having to use the lenses 2x extender to eliminate vignetting  with a straight through adapter any imperfections in the lens and any softness becomes quite obvious. Get a really good lens on a good adapter and the images are perfectly respectable, but a poor lens on an adapter will probably dissapoint.