Histogram Horizontal Axis

[font color=\'#000000\']Ever wonder why the brightest f stop has "half the available encoding levels" yet only occupies the rightmost fifth ( or fourth?!?) of the histogram screen? And how your black to middle grey can occupy the left half if the "Mid-tones" sit somewhere from 512 to 1024 on the 4096 scale? My guess is the histogram ( on a 2 to the 8 = 256 scale ...0 to 255 ) employs logarithmic units... constant fractions of the luminosity ..so that the luminosity is compressed and we can display ev units from brightest capture down to darkest capture. Duh... we knew that didn't we. Now the question...what is the ev increment for each of the 0 to 255 units? and where do they start/end ....at the same true luminosity level for all cameras using the same sensor?.[/font]