The Sony FS5 and PXW-X70 offer not just fantastic images and 4K functionality, but also flexible features including the ability to stream live footage straight from the camera, a feature that many freelance camera professionals and production companies specialising in live events would surely appreciate.
Sony recently announced their next firmware update for the PXW-FS7 and PXW-X70 cameras. The FS7 gains 4K (4096 x 2160) internal recording in XAVC-I in the form a free update in March 2015 in addition to ProRes HQ/422 at 1920 x 1080p up to 30p internal recording on XQD cards (requires XDCA-FS7 extension unit). The Sony PXW-X70, which at the moment is limited to 1080p, will receive a paid firmware update to allow for 4K UHD (3840 x 2160) in XAVC-L up to 30fps – the firmware update for the PXW-X70 is expected to be available in June 2015.
XAVC is a recording format introduced by Sony which can support 4K resolution at 60 frames per second. Colour sampling can be 4:2:0, 4:2:2 or 4:4:4 at 8-bits, 10-bits, or 12-bits. XAVC uses an MXF wrapper whereas the consumer version XAVC-S is an MPEG4 wrapper. XAVC allows for both intra frame and inter frame (long group of pictures) recording. If you are the sort of person who is turned on by phrases like MPEG4 wrapping, Sequence Parameter Set and flexible data payload you can download the technical white paper here.