Render each body through the profile its own files describe
Colour came from whichever matrix rawler happened to key `D65`, the second one was discarded, and the rendering was left linear. That is the dcraw default, and FR-DEV-3e names it as the reason people abandon a converter in the first hour: correct in the abstract, flat and poor on skin in practice. The decoder now builds a camera profile. - `ColorMatrix1/2` and `CalibrationIlluminant1/2`. rawler surfaces these as an illuminant-keyed map — for DNGs from the tags, and for native formats from its own camera database — so a Canon CR2 arrives with a tungsten matrix and a daylight matrix exactly as an Adobe DNG of the same frame would. Dual-illuminant support is therefore not a DNG feature here. - `ForwardMatrix1/2`, read straight from the root IFD, because rawler parses them and never surfaces them. Where a file carries both, they replace the inverted colour matrix: the same relationship measured in the direction rendering actually wants, rather than an inversion that amplifies the measurement error exactly where skin lives. - `AsShotNeutral`, used to estimate what the scene was lit by and to interpolate between the two calibrations in mireds. The estimate is circular — the temperature needs a matrix and the matrix needs the temperature — so it is a fixed point, three rounds, as Adobe's SDK does it. Bodies calibrated at neither D65 nor A stopped rendering uncalibrated as a side effect: a Phase One IQ3 carries D55 and D75 and used to get no matrix at all. And a base curve, applied per channel in camera RGB between the last adjustment and the conversion out of camera space — a toe, a steep midtone and a shoulder, which is the difference between a photograph and a scan of one. It is not an edit: no slider, nothing in the sidecar, because it belongs to the body rather than to anything anyone decided, and a sidecar is shared between bodies. It is not a develop node either, and `ops/README.md` now records why. It evaluates on the tone curve's own spline rather than a second copy, so a profile author placing a control point and a photographer dragging one mean the same thing by it. The curves are data. `core/dr-decode/profiles/base_curves.yaml` ships inside the binary as a floor and is superseded by any copy on disk carrying a higher `version:`, so a body can be added and distributed without a release — and, under the GPL, contributed. The comparison runs both ways: a stale pack cannot hold an upgraded binary back at last year's rendering. Canon EOS 6D and R6, Nikon Z 6 and D750, Sony A7 III and Fujifilm X-T3 ship with their own curves. Every other body gets a conservative default, which is much closer to right than the identity is for any of them. A JPEG gets none — it has already been rendered once, by the camera. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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Claude Opus 5