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.
Tag Archives: B4
Image quality with B4 ENG lenses on large sensor cameras.
This is something that comes up a lot and I get many questions about. In part because I designed the MTF B4 to Canon, FZ and E-Mount adapters. Budget adapters that allow you to use a 2/3″ B4 ENG lens on a Super 35mm sensor by using the lenses 2x extender or on a center crop sensor without the 2x.
The question is… what will the pictures look like?
The answer is… it depends on the lens.
Not a very helpful answer perhaps, but that’s the truth of it. Different lenses perform very differently. For a start I would say forget 4K. At best these lenses are suitable for HD and you want to have a great HD lens if you want good HD pictures.
But what about the “look” of the images? My experience is that if you put a wide range ENG zoom on a S35mm camera the look that you get can be best described as “2/3″ ENG look with maybe shallow depth of field”. Lets face it, ENG lenses are full of compromises. To get those great big zoom ranges with par-focal focus there are a lot of glass elements in those lenses. Lot’s of elements means lots of places where CA and flare can occur. The end result is often a lowering of contrast and color fringing on hard edges, the very same look that we are used to seeing on 2/3″ cameras. Typical cine or DSLR lenses tend to have simpler optical designs. Prime lenses are normally sharper and show better contrast with less flare than zooms due to there simpler internal design.
So don’t expect to put a typical B4 ENG lens on your S35mm camcorder and still have that crisp, high contrast digital cinema look. Of course B4 zooms are handy for the ability to zoom in and out through huge ranges while holding focus. So an adapter and lens may well make your S35mm camera more versatile. But if you want the best possible images stick to cine style lenses, DSLR lenses or zooms designed for S35.
