The container and codec wrapping your image data—MOV, ProRes, DNxHD. Dictates file size, compatibility, and editorial workflow. Wrong choice kills post-production schedules.
On set or in post-production: The choice of file format determines how quickly you can work, whether your hardware can handle it, and whether you'll have flexibility for color grading or editing later. It's not about the theoretical definition – it's about the consequences of your decision.
At its core, a file format is a combination of a container (the wrapper, e.g., MOV or MXF) and a codec (the compression method, e.g., ProRes 422 HQ or DNxHD). Some cameras output H.264 – cheap in file size, toxic for post-production. 4K H.264 from a smartphone? An editing station killer. Other cameras (RED, Alexa, ARRI) already deliver native or proxy formats on the card that feel like film – because they compress less and store more color information.
The practical reality: You need a capture codec (what the camera records), an edit codec (what the editor can cut smoothly with), and a delivery codec (what goes to the cinema or streaming platform). ProRes 422 HQ for the cut, DNxHD for VFX rendering, H.265 for the DCP – this isn't madness, it's workflow. If you get this wrong, you'll convert twice and lose time. Or worse: the editor sits on the edge of their seat every two seconds waiting for a frame.
Important: Color space and bit depth are part of the decision. 8-bit compression (some MOV formats) gives you hardly any room for color correction. 10-bit or 12-bit (ProRes or DCI codec) are standard for serious production. A Log codec (Sony S-Log, RED RAW) retains maximum color information but requires a LUT and more storage later.
On set, you ask yourself: How large can the file be? How long will my memory cards last? In post, you ask yourself: Can my NAS play this back? Does the VFX house have the same software? That's why large productions agree on a standard *before* the first day of shooting – and document it in the DIT sheet. The wrong format isn't an aesthetic problem. It's money you won't get back.