Originally Posted by darinp2
Going back to this part, I don't believe that is correct unless you want to count the light being blocked by the shutters. As long as 1/10th of the pixel area left is sending the light over the same number of steridians as the unblocked sub pixel was the luminous intensity from each sub-pixel is now 1/10th of what it was, whether using candelas or lumens.
Imagine a projector with a small imaging chip and the zoom lens left in one position so the beam size and angle don't change. Now put the projector in a mode where all the pixels are white and another mode where 10% are white and 90% are black. Would you claim that the lumens or candelas of light from the projector are the same in both cases?
Another way to look at it is to go back to the 70 candelas and instead of putting a shutter over 90% of each sub-pixel put a lens that focuses that light toward a side wall. The lensed part of the sub-pixels would send out a certain number of candelas and the unlensed part would too. You wouldn't say that those would now add up to more than 70 candelas, would you? If not, then the unlensed part would have to send out less than 70 by definition if the lensed part sent out any.
Do you disagree that the luminous flux outside the shutters goes down by 90% if shutters cover 90% of the sub-pixel area, for that example from earlier?
How about if shutters went all the way to blocking 100%? Would that change the luminous intensity or luminous flux?
Let's start from scratch.
If you have one light emitting molecule and you apply 0.1 micro-amperes to it it is liable to produce, say, 1 billion photons per unit time.
And if you have two similar light emitting molecules and apply the same 0.1 micro-amperes to them, they are still liable to produce 1 billion photons per unit time, but now each light emitting molecule produces only half a billion photons. In this case, the luminous intensity of each molecule halved, but the net luminous power/flux of the two light emitting molecules ( i.e. the number of photons produced per unit time) stayed the same as in the first example.
And if you were to put ten similar light emitting molecules together and feed them an amperage of 1 micro-ampere (which would yield 10 billion photons per unit time in total) and then were to cover up nine of them, the uncovered light emitting molecule would produce 1 billion photons, and among the nine covered light emitting molecules each light emitting molecule would also produce 1 billion photons, because all ten light emitting molecules would have the same current density of 0.1 micro-amperes, but the total luminous power of the ten molecules would decrease by 90 percent (when nine of them are covered up).
Now let's get back to the projector example. If you were to cover 90 percent of the lens with a shutter then its luminous flux would decrease by 90 percent (or in other words, the amount of photons coming out the lens would fall by 90 percent if 90 percent of it was blocked), but the luminous intensity of the remaining 10 percent would stay the same.
And if you were to cover 90 percent of each pixel of the projector then the luminance of the entire screen on which the projector was projecting light would decrease by 90 percent, however the remaining 10 percent of each pixel would still maintain the same luminous intensity as before (i.e. if the projector was OLED-based then each light emitting molecule would still produce the same amount of photons per unit time).
I hope this makes things a bit clearer.