Quote:Yes you're right, the CR number isn't reduced that much.
But the black level stays the same so on a small screen it may be perceived as not being black enough.
The big problem with brightness numbers in lumens and linear conrast ratio numbers is that our eyes don't work linear. Like all other human "sensors" it works highly nonlinear, more in a logarithmic or exponential way.
but in optics there are no logarithmic scales AFAIK, like it is in acoustics with the decibel scale.
Giving brightness numbers in lumens is like giving Sound Pressure levels in Pascals...
I think for our ears it was easier to create a logarithmic scale. Maybe for the eyes it's not so easy because we have an iris in our eyes and can adapt to very different brightness levels. Otherwise 3D with only 150 lumens or so behind the glasses wouldn't work.
going back to the black level of the HW50: I found that the iris only closes to its minimum with a totally black image. Only there the HW50 was darker than the JVC X30 I compared it to.
In a total black image the iris didn't close immediately, but needed half a second or so. So no real time there.
With typical dark pictures of space with a few stars, spaceships and planets, the X30 had much better blacks. My perception was that the iris of the HW50 didn't close very much with such scenes, so the maximum white was still good but the blacks were not as good as with the X30.