View Full Version : The most interesting question


holocinema
10-13-07, 10:57 PM
so hdm formats store images at 16-235 ......ok
if u use a gamma 2.6 that = 220 levels to the power of 2.6 = 1231115 right
now forget about absolute black level for one moment
if i understand this correctly, to really show this perfectly u would need
a display that has a maximum luminance of 1231115 times its minimum non zero luminance in other words a ansi contrast ratio of 1231115 to 1 (still not taking into account zero black)
now where to put these levels in terms of luminance i dont know, lets see
we coud have 1231 nits to 0.001 nits
or 12311 nits to 0.01 nits
or what ever
but i think 12311 nits to 0.01 is better, our eyes need time for Dark adaptation plus our eyes have less dynamic rage at brighter levels so we wont notice the limited 220 steps + brighter more saturated colors and most important closer to real life almost ( hdr)
look at what this guy found out by testting
( http://delivery.acm.org/10.1145/1280000/1276425/a38-akyuz.pdf?key1=1276425&key2=5100332911&coll=&dl=ACM&CFID=15151515&CFTOKEN=6184618 )

so my question is, am i thinking right or what because if i am right then beautifull there is still room for improvment of image even with 16-235 and we have the illusion of hdr for free

mastacow53
10-14-07, 09:29 AM
My head just exploded.

tomanystraydogs
10-14-07, 01:07 PM
head on, apply directly to the forehead

/

Jigen
10-14-07, 04:50 PM
so hdm formats store images at 16-235 ......ok
if u use a gamma 2.6 that = 220 levels to the power of 2.6 = 1231115 right
now forget about absolute black level for one moment
if i understand this correctly, to really show this perfectly u would need
a display that has a maximum luminance of 1231115 times its minimum non zero luminance in other words a ansi contrast ratio of 1231115 to 1 (still not taking into account zero black)
now where to put these levels in terms of luminance i dont know, lets see
we coud have 1231 nits to 0.001 nits
or 12311 nits to 0.01 nits
or what ever
but i think 12311 nits to 0.01 is better, our eyes need time for Dark adaptation plus our eyes have less dynamic rage at brighter levels so we wont notice the limited 220 steps + brighter more saturated colors and most important closer to real life almost ( hdr)
look at what this guy found out by testting
( http://delivery.acm.org/10.1145/1280000/1276425/a38-akyuz.pdf?key1=1276425&key2=5100332911&coll=&dl=ACM&CFID=15151515&CFTOKEN=6184618 )

so my question is, am i thinking right or what because if i am right then beautifull there is still room for improvment of image even with 16-235 and we have the illusion of hdr for free

While I didn't get every technical term you threw around there, yes there's a HUGE way to go before displays can get even close to providing the contrast available in reality. That's why games have implemented real time HDR, because while we don't have displays that will require the human eye to react, we can simulate that reaction (or that of a camera) within the 3d rendering itself.

I wonder if humans will EVER be able to create a display with the contrast ratio even near reality (of course you wouldn't want to create a display that can be as bright as the sun, especially sitting 5 feet from it, unless you want to destroy the earth itself...), but even what we're used to as far as contrast, without the extremes is a long ways off.

If you're thinking of simplifying HDR calculations by cutting out the subtle gradients, no, that's not going to work because it would mess up the calculations and our displays can't do the work that HDR rendering can (not able to display that level of contrast).

holocinema
10-14-07, 06:53 PM
there is nothing too technical about what i said,
with so much talk on this fourm about high contrast ratios
I just wanted to point out that to display 16-235 images at gamma 2.6
you need a display that has a maximum luminance of 1231115 times its minimum non zero luminance in other words a ansi contrast ratio of 1231115 to 1 (still not taking into account zero black)

ccotenj
10-14-07, 09:22 PM
so you pointed it out...

now what is your point? :confused:

Jigen
10-18-07, 01:40 AM
there is nothing too technical about what i said,
with so much talk on this fourm about high contrast ratios
I just wanted to point out that to display 16-235 images at gamma 2.6
you need a display that has a maximum luminance of 1231115 times its minimum non zero luminance in other words a ansi contrast ratio of 1231115 to 1 (still not taking into account zero black)

Honestly, I don't think you have any idea at all what you're saying.

First off, by saying 'a display that has a maximum luminance of 1231115 times its minimum non zero luminance' you should just type 1231115:1 contrast ratio. That's the accepted terminology. Noone would take 'zero luminance' as a starting point for any TV, because it would be off, if you consider 'zero' to be black as the set displays it, then you're sorely wrong because zero should be considered.

If you're using 16-235 and add gamma, you're going to be distorting the image more than is necessary for a HDR display. It'd be like turning the brightness and contrast to max on my TV and then complaining that I don't have decent image quality.

k33p0u7
10-18-07, 03:46 PM
Holodeck from Star Trek?

CruelInventions
10-18-07, 11:18 PM
this thread = good times.
don't ever change, holocinema.