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thanks, this kept me from asking in my ignorance, what does all of this mean?
It means Sony uses a kind of file compression that is a bit like the gamma curve in a normal sRGB file. It works very well, and has very (extremely) little bearing on the available image quality, or tone resolution. It's much more important that what you feed IN to the system is accurate than just piling on more decimals.
Each Ev step is a doubling of the number in a raw file, which makes the top number needed escalate very quickly... 1Ev = 2x, 2Ev = 4x, 3Ev = 8x, and so on.
The brightness step between the raw file numbers "10" and "20" is visually the same as the difference between "100" and "200", that is visually the same as the difference between "1000" and "2000" - exactly one Ev step. But the darker zone takes up 10 data points, the brighter zone takes up 1000 data points of "storage capacity".
The reason we use higher accuracy (12-14-16 bits) files is that we quite literally waste a lot of numbers in the highlights.
Which do you think gives the better accuracy if you try to measure the length of a matchbox:
Using a calibrated vernier scale that gives 2 digits of accuracy, but you only report one of them - like "52.4mm"?
Using a crude wooden school ruler with one half digit of accuracy, but you report two digits - like "52.50mm"?
Just looking at the numbers, you might think that 52.50 is more accurate than 52.4, since it has two decimals in stead of one - but actually we know that the other number is more accurate, since it was measured more accurately.