Rolling on a raw DNG cine camera

Today I set out toward something I've circled for a while: a raw-format 1080p DNG cine camera, built from parts, that writes real uncompressed frames instead of the baked, compressed video every off-the-shelf body hands you. No black box. Every step of the image path is mine to open up, break, and understand.

I'm building this alongside Claude as the co-engineer on the bench — reasoning through the sensor pipeline, the capture code, and the file format with me as we go. This log is where the work gets written down honestly: what worked, what didn't, and what I'd do differently. If you found this domain, you're early. Pull up a chair.

01What "raw" actually means here

Most cameras throw away most of what the sensor sees. They debayer, apply a curve, crush it to 8-bit, and compress — decisions locked in before the file ever hits the card. Raw keeps the sensor's own numbers: the untouched Bayer readout, full latitude, nothing thrown out. DNG is the container for that — an open, documented raw format — and CinemaDNG is simply a sequence of those frames, one per exposure, that grades like film and bends far further in post than any compressed clip.

1080p is the deliberate starting point, not a limit. At full 1080 I can chase a clean, honest capture path first and worry about resolution once the plumbing is solid.

02Why a Raspberry Pi 5

The brain of this first build is a Raspberry Pi 5, 8GB. It has the two things a raw pipeline actually needs: a CSI-2 camera interface that speaks straight to a sensor, and — new to the Pi 5 — a proper PCIe lane, which is the difference between "records a few seconds" and "records." Raw frames are heavy. Eight gigs of RAM gives the capture buffer somewhere to breathe while frames head to fast storage.

03The road from here

Here's the rough course. It'll change — that's the point of writing it down early, so I can watch it change.

1. Get the sensor talking todayPi 5 booted, camera on the CSI-2 ribbon, libcamera seeing a live preview.
2. Pull one true raw frameCapture a single uncompressed Bayer still and confirm the bit depth is really 12-bit, not silently clipped.
3. Write a DNGWrap that frame in valid DNG that opens and grades cleanly in a real editor.
4. Make it a sequenceFrame after frame to fast storage without dropping — the moment it becomes a cine camera.
5. Give it a bodyPower, a monitor, a record button. Something you can actually hold and point.