The camera can hand over what the sensor measured, before any of its own processing — see raw sensor data, as Adobe DNG for the endpoint itself. The raw editor is what opens one without leaving the browser: it develops the frame on your machine, measures the sensor, and can calibrate the camera's colour from a chart.
It is not part of the firmware. The web interface fetches it the first time you open it, so the camera needs a route to the internet for that one request; after that the browser caches it. A camera with no route out shows the raw page with a download button and an explanation instead, which is the page working as intended rather than a failure.
Not every camera can do this. Raw is a HiSilicon and Goke feature; other SoC families do not serve it, and neither do the oldest HiSilicon parts. The menu entry is there on every camera regardless, so the page itself is where you find out:
- This firmware does not serve raw frames — the hardware cannot, and nothing will change that.
- Raw capture is switched off for this camera — it can, but
isp.rawModeisnone. Turn it on in Settings, under Live, where the image settings are drawn.
The endpoint's own section has a one-line check that answers the same question from a shell.
Where it is available, Camera → Raw in the web interface opens it. It takes a frame straight away, which is several megabytes off the camera and takes a few seconds — there is nothing to press first.
The picture. On current firmware the frame arrives with the camera's own white balance recorded in it, so the first render is what the camera thought the scene looked like rather than a neutral one. Older builds write a placeholder balance of 1:1:1 and a black level of zero instead — the panel shows what your file actually carries, and how good the colour is depends on your firmware says how to tell which you have.
| Raw | Which corner of the sensor's grid is red. It comes from the file; the Bayer probe at the foot of the panel narrows it to two candidates and cannot settle between them, so if the colours look swapped, try the other. |
| Black / White | Where the sensor's floor and ceiling sit, taken from the file. Moving White brightens the picture — a rendering choice, not a measurement. |
| Demosaic | How the missing two-thirds of each pixel are reconstructed. RCD is the default and the closest. None shows the mosaic itself, which is what you want when the question is about the sensor rather than the picture. |
| Pick a neutral | Click anything in the frame that ought to be grey. This is the fix for a colour cast, and it reads the mosaic rather than the picture on screen, so it measures the scene rather than the balance already applied. |
If the first render has a cast, there are two quite different reasons and the White balance panel tells them apart. Where it shows a real measured balance, the cast is the camera's own automatic white balance being wrong, faithfully recorded — a raw frame carries the balance the camera chose, mistakes included. Where it shows 1:1:1, the file simply has no balance in it and the cast is the sensor's raw response, with milky blacks to match because the black level is zero as well.
Picking a neutral fixes both, and is the quicker route either way.
Measures the sensor rather than the picture: how many pixels disagree with their neighbours by more than the noise explains, the black level the frame implies against the one the file claims, what has already clipped, and how noisy the rest is.
Read the number with the two things beside it, not on its own. Pointed at an ordinary furnished room the scan will report hundreds of pixels, and almost all of them are detail in the scene rather than faults in the sensor. Two things in the panel say which you are looking at:
- Spread. Real sensor defects are scattered at random across the frame. Detail in a picture is not — it sits wherever the picture had detail. A figure near 1 is scattered, as the screenshot above shows; well below 1 means the scan is describing the room, and the panel says so in as many words.
- The histogram. Every pixel by how far it sits from its neighbours, on a logarithmic scale, against the curve noise alone would produce. Where the bars follow the curve there is nothing there; the tails are what is left.
To get an answer you can act on:
- Point it at something plain — a blank wall, or the lens cap. The flatter and darker the frame, the less there is to mistake for a defect.
- Use Where to look → Darkest so the scan only believes the dim parts of the frame, where a defect stands out and detail does not.
- Take about five captures, keeping each one, moving the camera between them. A faulty pixel appears in all of them wherever the camera points; noise appears once and never again; detail moves with the view. The panel tallies them and says which it is looking at.
One capture is never enough, and five of the same unchanged view is not either.
Measures the camera's colour against a 24-patch chart and can write the result back, so the camera's own picture — not just the raw frame — comes out closer.
Put a chart in front of the camera, reasonably flat on and evenly lit, and open Calibrate. It looks for the chart by itself and puts four corners on it; drag any that sit off, and the dots show where each patch will be read from. Then Measure the chart.
The result reports a mean and worst ΔE — how far each patch landed from where it should be. Under 3 is a good fit. A spiky light source, which most LED lighting is, will not do better whatever the chart, so measure under something continuous if the number matters.
Writing it to the camera is deliberately hard to regret: the new colour is applied live and put back by itself after thirty seconds unless you confirm you can still see a sane picture. That is the bargain a display resolution change makes, for the same reason — a bad colour matrix survives a reboot.
The editor is fetched from the internet on first use. If it does not arrive the raw page says so and still offers the frame as a download, which any desktop raw converter will open. Nothing else in the web interface depends on it.
Raw capture is also demanding on small cameras — a frame is several megabytes and the camera needs that much memory while it serves the request. The memory notes beside the endpoint are worth reading before using this on a board with little RAM.
OpenIPC/raw-editor. The reasoning behind the choices here — why RCD is the default demosaic and what the others cost, why the Bayer probe stops at two candidates, why the neutral picker reads the mosaic — is in that repository's README, along with what it takes to send a patch.