Sony Alpha Rumors recently posted that Sony is working on a hybrid camera that allows for Z-axis movements of the sensor. This would allow the camera to not only use both A- and E-mount lenses “natively” but also allow even manual focus lenses to autofocus. I was very skeptical of this but after looking at the Contax AX system I see where it can be done. I do see several issues:
- To autofocus using the Z-axis the lens must be set to infinity. Not all lenses perform best at infinity and this seems like it would negate things like floating elements which are supposed to optimize focus for different distances. Also, this will still require at least rudimentary control of the lenses focusing system.
- Adapters will still be necessary as different mounts have different bayonets and throat sizes. This also applies to A- and E-mount lenses. I don’t have any A-mount lenses at the moment so I’m not sure how different the bayonet mount is but even if you correct for the registration difference the lens still has to fit on the mount. So you will still have the traditional weaknesses of adapter plus a new moving part (the z-axis translation) that can break, jam, etc.
- The Z-axis is rumored to have 18mm of movement. That implies an E-mount, however 18mm of registration distance for the E-mount plus an additional 18mm doesn’t not equal the 44.6mm of the A-mount.
Issues 2 & 3 may have some novel solutions. The camera could use an FZ-mount (it will certainly be big regardless because of all the added registration flexibility and electronics) which, while still requiring adapters, is built to be adapted and is very robust. The cinema industry would not have embraced it if it wasn’t.
If the 18mm of travel mean 18mm of travel in both directions along the Z-axis then the sensor could live at 34mm which would open up a world of possible lens opportunities as well as providing E-mount lens mounting and focusing (it could get closer than 18mm) and A-mount lens mounting and focusing (44.6mm). It would also cover Canon (44mm), Nikon (46.5mm), and Leica R (47mm) all the way to Arri PL (52mm). (list of mount types of registration distance)
Assuming it uses the battle-test FZ mount and SLR-like ergonomics it could be targeted as much towards the digital cinema community (and the EOS C100 & C300) than photographers.