> In a sense our eyes experience contrast on a sliding scale
There's a whole visual center to check the amount of incoming light and adjust your pupils for you. It's intentionally reactive.
> and there is no absolute zero in the system.
There maybe is. I think we call that "blind."
> broadcast systems historically used 16-235 as their luminance range for SDR
Mostly because it was a fully analog system and these all translate down to signal voltage. Jokingly NTSC used to be referred to as "Never Twice the Same Color" due to being a compromise bolted onto the side of an already compromised system.
>> and there is no absolute zero in the system.
> There maybe is. I think we call that "blind."
If you go looking into that, you'll see that the reality is far far more complex [0]
"The number of people with no light perception is unknown, but it is estimated to be less than 10 percent of totally blind individuals."
[0] https://chicagolighthouse.org/sandys-view/what-blind-people-...