DxOMark publishes its scores for Red Helium 8K image sensor prototype, and tries to explain exceptionally high Raw performance of this APS-H sensor, even in comparison with Sony full-frame ones:
Puzzled by seemingly impossible improvements in SNR and DR over Sony BSI full-frame sensor, DxO checks Row files for pixel noise correlation, a sure sign of applied spatial noise reduction. However, there was no any correlation:
Then, DxO suspects that Red has applied a temporal noise reduction: "This technique, called temporal noise reduction (TNR), is most commonly used in video, since there are many successive frames to work with. However, temporal correlations across a time axis are not relevant when analyzing the image quality of a single RAW image, as they do not impact any RAW converters.
Whatever noise reduction system RED employs creating the RAW images from the Helium sensor, its presence means that we aren’t measuring just the RED sensor, so its results aren’t directly comparable to those from camera sensors we have tested from other vendors, whose RAW results come straight from the sensor with no prior noise reduction processing."