Sony's full-frame documentary cinema camera — a 6K Exmor sensor, the FS7's successor.
The Sony PXW-FX9 is a full-frame documentary and cinema camera announced at IBC in September 2019, the direct successor to the hugely popular FS7. It brought a 6K full-frame Exmor R sensor to Sony's shoulder-friendly XDCAM body style and quickly became a default hire-list camera for UK factual television.
The 6K sensor oversamples to 4K at up to 50/60p in 10-bit 4:2:2 XAVC-I, with dual base ISOs of 800 and 4000 and around 15 stops of claimed dynamic range. Fast Hybrid AF with face detection was a first at this level, and the electronic variable ND filter remains one of the great documentary features, allowing seamless exposure rides. It uses a locking E-mount, records to dual XQD/CFexpress-compatible slots, ships with S-Cinetone, and accepts the XDCA-FX9 extension unit for 16-bit RAW output, V-lock power and network features.
The FX9's significance is that it made full-frame the norm for broadcast documentary work: BBC and other UK factual productions adopted it en masse, and its combination of autofocus, variable ND and shoulder ergonomics has kept it relevant even after the FX6 arrived. That fleet adoption means the UK used market sees a regular flow of well-specced ex-production bodies.
Used FX9s are frequently ex-hire or ex-production, so ask for the hour count and service history. Check the smart grip arm and rosette for play, the viewfinder LCD for dead pixels and the loupe for scratches, and run the variable ND across its full range. Confirm firmware is at version 3 or later (which added the full AF and format feature set), test both media slots, and inspect the E-mount locking ring for wear from heavy cine zooms. Bodies bundled with the XDCA-FX9 unit or spare batteries are worth a premium; bare bodies with tired hours are not.