Then I pull down gamma and the reds rotate even more and line up with the red on the vectorscope, then I increase gamma making things much brighter and the red can no longer be represented in the gamut anymore and shifts widely into orange. I made this quick video to demonstrate this with your DNG - here you can see its decoded as 709, then I boost saturation and you can see the red LEDs rotate in hue a bit on the vectorscope. So generally as the 'brightness' increases the amount of saturation it can be reduces - this is particularly true for red. I think I need to show something else here since many don't consider it (this is for anyone interested), but colourspaces and their gamuts are volumes, even though for convenience often just plotted as 2D on CIE chromaticity plots. You either need a larger display gamut and a display that can reproduce it with more DR (hence why there is a push for HDR and 2020 displays etc), or need to make a compromise/choice of some kind to "represent" it on a device not capable of reproducing it accurately. That's why there are disagreements about which method is better, its subjective because it cannot be accurately displayed in 709. But any method is a compromise because that colour/brightness cannot be accurately represented by your (709 display) gamut. So if with an 'accurate' transform to 709 the LED is turning orange instead of Red its because either potentially a channel was clipped from the bright LED, and/or because the actual colour is beyond the display gamut of 709 and needs to be remapped somehow, either by compression or some other method. See what I wrote before in parenthesis - "(unless the sensor is clipped in areas or gamut mapping/compression is required etc)" When they say red, I see red, but with 709 conversion they say orange, I see orange. Noel Sterrett wrote:But the Vectorscopes tell the tale. I can't answer that, and without an answer, I don't think camera/codec tests will help figure anything out. They are decoding the same DNG so should they not, in theory, be identical? The main question is why is there such a dramatic color difference between the 709 Decode and the BMD Decode. The effects, like jaundiced looking yellow peaking faces, are easy to spot. I had never in two decades encountered a digital camera that could capture and accurately reproduce the color of bright, normally blown out and discolored light sources like taillights and stoplights along with everything else. When I stumbled upon the decoding of the stoplight image, I was excited and delighted. It's different for BRAW only because the Resolve code for decoding BRAW is not the same as that for DNG. How could the BMD Decode produce pure red?Īt this point, all the above leads me to guess that the result is a colorspace phenomenon created by Resolve mathematics rather than specific to the camera or the BRAW codec. The DNG decode to Blackmagic followed by a CST to 709 (BMD Decode) creates pure red values for the stoplight: RGB 255 0 0. The straight DNG decode to 709 (709 Decode) creates non-zero values for blue and green for the stoplight center: RGB 255 71 15.Ģ. What's happening here? Is it the camera, uncompressed DNG's, BRAW, Resolve?Īs Hook pointed out, two other DNG decoding methods produce results with BRAW that are quite similar to DNG.ġ. John Brawley wrote:Noel can we prevail upon you ?Might not be needed.
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