On Oct 6, 2022, at 2:23 PM, Jeff Nova via colorsync-users <colorsync-users@lists.apple.com> wrote:

I keep seeing "Standard Light A" in DNG metadata. Presumably this is just Standard Illuminant A? Just making doubly sure.

You see it where (and which tag)? You might find the answer here: https://www.kronometric.org/phot/processing/DNG/dng_spec_1.4.0.0.pdf <https://www.kronometric.org/phot/processing/DNG/dng_spec_1.4.0.0.pdf> "One or Two Color Calibrations DNG provides for one or two sets of color calibration tags, each set optimized for a different illuminant. If both sets of color calibration tags are included, then the raw converter should interpolate between the calibrations based on the white balance selected by the user. If two calibrations are included, then it is recommended that one of the calibrations be for a low color temperature illuminant (e.g., Standard-A) and the second calibration illuminant be for a higher color temperature illuminant (e.g., D55 or D65). This combination has been found to work well for a wide range of real-world digital camera images. DNG versions earlier than 1.2.0.0 allow the raw converter to choose the interpolation algorithm. DNG 1.2.0.0 and later requires a specific interpolation algorithm: linear interpolation using inverse correlated color temperature. To find the interpolation weighting factor between the two tag sets, find the correlated color for the user-selected white balance and the two calibration illuminants. If the temperature white balance temperature is between two calibration illuminant temperatures, then invert all the temperatures and use linear interpolation. Otherwise, use the closest calibration tag set". Andrew Rodney http://www.digitaldog.net/ <http://www.digitaldog.net/>