Uncompressed 10-bit image format for digital intermediate mastering — VFX, DCP, color grading standard. Storage monster, but lossless from scan through final deliverables.
You're sitting in the grading suite and the colorist is loading the dailies — and then DPX comes in. Uncompressed, 10-bit per channel, sequenced in folders, each frame a single file. This has been the industry standard since the digital intermediate era, because nothing is lost between the scan of the original negative and the final release print version. Every pixel remains exactly as scanned, no DCT artifacts, no compression weaknesses.
DPX originated in the 1990s as an open format from Digital Picture Exchange — developed precisely for this workflow: large-format, uncompressed images that travel over networks, can be read by different systems, manipulated in VFX compositing, and can go back into grading. The storage size is considerable — a Full HD image (1920×1080) in 10-bit DPX: just under 8 MB. A 90-minute feature film production in 2K (2048×1556)? You quickly need 2–3 Petabytes for all cuts and versions. That's the price for lossless quality. That's why studios outsource archiving, using LTO tape systems or cloud-based vaults.
In practice, you have several variants: DPX with an Alpha channel for compositing, DPX in Log curves (when scanned directly from the negative), or Linear for further processing. VFX houses work with it sequentially — each shot comes in as a folder with 200, 300, 1000 frames, is composited in Nuke or similar, and then goes out again as a DPX sequence. The editor is waiting impatiently, but without DPX quality, color stability between VFX plates and original footage would be questionable. During DCP mastering (Digital Cinema Package), you then convert from DPX to compressed intermediate formats, but the masters themselves are DPX, archived on secure servers.
The annoying thing: each system reads DPX slightly differently. Byte order, color space metadata, timecode handling — surprises can arise. That's why you always check against reference monitors and work with color management profiles. OpenEXR and ProRes RAW are now competing, but in the classic mastering workflow, DPX remains the gold standard — because studios, archives, and cinemas rely on it.