RawTherapee - Tonal distribution in a luminance histogram (linear with gamma correction):
To achieve real blacks and whites, both extremities next to clipping appear to be relevant. The most part of the x-axis refers to the interval -2/+2 EV, with the darkest tones here represented at -3 EV.
We can say that the -2/+2 EV interval (a small interval indeed compared to the real world luminance) is the descriptive part of the photograph, while the extremes are its glory.
But be careful to clipping.