The Worst Time to Find a Delivery Error Is After a 100GB Upload

A client delivery might take hours to upload. A technical mistake takes seconds to detect. That imbalance is the entire argument for preflight.

One Wrong EXR Setting

A studio finishes four shots. Three are rendered as 16-bit half-float, ZIP-compressed EXRs. One artist accidentally used DWAA.

The frames look fine, because DWAA is a good compressor. It is also lossy, which is why delivery specifications routinely prohibit it — a client planning further grading or compositing needs the original data, not a visually convincing approximation.

The upload completes. The package is rejected. The studio re-renders, repackages and re-uploads, and the schedule absorbs a day that a scan before the transfer would have saved.

What Delivery Specs Actually Constrain

Specifications look bureaucratic until you have failed one. Most constrain the same handful of properties, and each exists for a reason.

Compression. Lossless codecs — ZIP, ZIPS, PIZ — preserve the data. DWAA and DWAB do not, and are frequently banned outright in a mastering chain.

Bit depth. Half float is standard for most VFX delivery; full float doubles file size for precision rarely needed downstream, and integer formats discard highlight information a grade may want.

Channel naming. An EXR can carry many channels. If they are not named as the spec expects, the client’s automated ingest may not find the image at all.

ProRes flavour. 422, 422 HQ and 4444 are not interchangeable, particularly where an alpha channel is involved — only 4444 carries one.

Naming and structure. Ingest is usually automated. A filename that does not match the expected pattern can fail before a human sees it.

Why This Is Not Caught by Looking

Every property above is invisible in the picture. The frames look correct in a viewer, because they are correct — they simply do not meet the specification.

This is what separates delivery QC from creative review. A supervisor watching the shot cannot see the compression setting, and is not looking for it.

The Cost Is Not the Re-Render

Re-rendering four shots may be an hour of farm time. The expensive parts are elsewhere.

Another upload window. A missed delivery deadline, sometimes with contractual weight. Renewed client attention on the vendor’s reliability. And the compounding effect where a rejected delivery arrives during the following week’s work.

Vendors are assessed on how often deliveries land clean. A rejection over a compression flag costs more credibility than the underlying error deserves.

Multiple Nets, Different Heights

Preflight is the last checkpoint, not the only one. Shot tracking asks whether the right shots and versions are present. Project validation asks whether the comps are healthy and portable. Preflight asks whether the rendered package meets the spec.

Catching a problem at the first net is cheaper than the second, and dramatically cheaper than the third — but the third is the one standing between the studio and an awkward email.