Originally Posted by
odds
To me, linear means "cooked" in the sense that a process calculated RGB pixel data from Bayer or X-trans matrix capture ("raw"). If Sigma means Foveon, the RGB is served directly from the sensor, no cooking required. Side note: Nikon held/holds a patent (US patent 7,138,663) on a RGB type sensor, potentially a Foveon competitor, but I don't think it ever materialized beyond their lab.
I have seen the "linear DNG" problem on several occasions, first when I wondered if I should convert to a DNG workflow and learned that a DNG created from a raw file by one application did not work with my other DNG-enabled applications. That said, Nikon NEFs created out of camera by Nikon software did not always work with other NEF-enabled applications. Back then I decided to stay clear of DNG.
Years later I got a Leica Q where "raw" meant Bayer DNG. That was OK apart from a few quirks with my Photo Mechanic/Capture One setup. My Leica got soaked in fresh water some weeks ago and the repair shop just sent me a "beyond repair" message :-(
DNG files cooked from a raw can contain a copy of the raw data, and I think some DNG-enabled applications can work with raw data embedded as additional data in linear DNG. Capture One may be one such application. I do not know if embedded raw data makes any difference for RT, but it may be worth an experiment if you convert your raw files to DNG.
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Odd S.