Originally Posted by Jeff J
I found this thread
that has a decent amount of data on average blu-ray bit rate.
using simple math, if the max bit rate for video is 40 Mpbs and the extra data requirement for the 3D stream is 50%, this would drop the max for the main steam down to 26.7 Mpbs (ie, 40/1.5*Max). There are a lot of discs on the above list with average bit rate way above 26.7 Mpbs. so, it would appear to be at least some concern for quality issues, especially at peak levels.
I'm sure the 50% is some sort of average and not an absolute...it will be interesting to see bit rates (and overall pq) for the first real discs to see how the bit rate/quality is balanced between the two different streams...
Yes - your rough math is correct. Of course the 50% more for the second channel is probably a best-case average, but it shouldn't vary that much, after all the other eye will be seeing something pretty similar to the first eye.
As to whether it has an impact on PQ, my guess is that it won't be much of a factor, except possibly in high-motion sequences, which probably won't be discernable anyway. I think it's a fair trade for the extra benefit of 3D.
Originally Posted by Jeff J
as far as the brightness reduction due to the glasses, the 60% does not jive with perception at all. I was thinking that it was not going to be close to the 50% number - the non-linear response of the eye is a big factor here. For comparison purposes, I just measured a pair of sunglasses and found 78% and 82% reductions (each lens).
This makes sense, although I would be quick to point out that what you measured from sunglasses is not going to be stricly the reduction due to polarising.
That said, a polarising filter will filter light in only one plane, but it's not like half the light is vertical, and half the light is horizontal - the light is scattered all over the compass, so to speak - so on a regular, non-polarised light source a polarised filter will reduce the light by significantly more than 50% - the 62% and 64% numbers above seem realistic, for a regular light source.
However, on a polarised source such as a 3D projector, which is only putting out, say, horizontally and vertically polarised light, then the reduction would be about 50% - since much of the other light at the in-between polarities would already have been filtered at the projector.
Personally - I prefer the shutter glasses over the polarised glasses systems. They are brighter, higher contrast and more enjoyable, in my opinion.
I saw movies like "Polar Express" in an IMAX theater with the polarised system, and they didn't hold a candle (pun intended) to the Real D system I watched Avatar with.
I was worried about the shutter lens glasses systems in the past, because the "old school" systems I saw a few years ago had lower refresh rates, and the flicker was just awful, especially if flourescent lights were around.
But what I saw with the Panasonic demo at CEDIA, and in the theater with Avatar, were vastly different - much better. So, at this moment in time, I am definitely in the Shutter Glasses camp.
By the way - if anyone want to know what LED projection systems will be really good at, it's 3D. Flash those little LED suckers at 120hz or 240hz and you've got yourself a 3D projector by just re-designing the board and the software - no fancy gimmicks to attach to the light path.