Sporgon said:jrista said:Sporgon said:For those that show pictures of iridescent black and white subject where the software is showing both highlight and lowlight to be lost; prepare for disappointment in the increased DR. For a given exposure you are getting no more highlight range, so, to preserve the highlight with your new higher DR camera you under expose to hold the highlights. But even with your previous longer exposure you had lost all shadow data, so by under exposing to preserve highlights with a camera that doesn't actually have any more highlight range you use up your extra DR range in the shadows anyway, and you end up trying to lift zero data.
The extra DR does have occasional advantages in a very narrow EV band, but this example isn't one of them.
There is no such thing as "highlight DR", nor is there "shadow DR"...there is simply DR. You either have more dynamic range or not. Dynamic range is by definition the ratio of the full well capacity to the read noise floor. This is something I hear a lot from Canon users, and it's just a misconception, a misnomer. Dynamic range represents the entire range of tones the camera can discern, without segregation.
In practice, with a camera that has nearly 14 stops of DR, you can indeed back off exposure a bit to preserve highlights, and still have plenty of room left to recover detail out of the shadows, and with significantly less noise than a camera that has 11 or even 12 stops of DR. The shadows won't be totally noise-free, but they don't need to be. They just need to have low enough noise to support an acceptable shadow push to reveal the right amount of detail in them.
You know exactly what I mean: ability to record a greater light density within the overall EV range of the camera.
The current greater DR cameras cannot do this so to preserve highlights you have to use a faster exposure - relatively - and then use the greater shadow recovery. Then what I described above is exactly what happens in this situation. I know. I bought an Exmor censored camera with a purported 14.5 stops of DR at 100 ISO, and in the intense back and white scenario that I describe above it is of little benefit - precisely because it clips the highlights at the same exposure as the older Canon camera.
This is my whole argument with those that hype up the odd stop or two of dynamic range; they speak as if it is able to record a higher light density and it can't.
But it can in essence and you are still thinking about it all wrong. You are free to expose so as to not clip the highlights without having to then end up with no shadow detail. You set the exposure as needed to not clip but then with say Exmor vs current Canon you can still make use of a few stops more in the darkest parts and have a real usable signal there.
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