Truth about Contrast Ratio ***> A must read for all <***

[Nielo TM]

Please read the whole post because this is very crucial information and it took me three hours to compose.



Contrast ratio, what do we know about them? Well all know, higher contrast means better picture quality. Is this actually true? The answer is yes and no.



Let's start with PDP and LCD. As you may already have noticed, LCDs and PDPs are emerging with contrast ratios up to 10,000:1. Do you wanna here a little secret? Those number aren't true, infect, it's a pure lie to deceive you.

Big numbers sells, that's a fact. When tested, the almighty 4000:1 Panasonic PDP only had 810:1 and Philips with 10,000:1 had 1613:1 (1108:1 ANSI) of true contrast ratio. The difference between the two is astonishing and yes, they've used Dynamic Contrast with pinch of marketing scheme.



Surprisingly, LCDs are very close to PDPs. In fact, the Sony BRAVIA KDL-40S2000 is very close that of Pioneer PDP-5060HD as the difference between two is 57:1.





Here is a full technical repot from AVSForums.


AVSforums







The human eye also has very low contrast. It takes a while for the eye to achieve maximum contrast, which is 1,000,000:1.



Dynamic range:

At any given instant, the retina can resolve a contrast ratio of around 100:1 (about 6 1/2 stops). As soon as your eye moves (saccades) it re-adjusts its exposure both chemically and by adjusting the iris. Initial dark adaptation takes place in approximately four seconds of profound, uninterrupted darkness; full adaptation through adjustments in retinal chemistry (the Purkinje effect) are mostly complete in thirty minutes. Hence, over time, a contrast ratio of about 1,000,000:1 (about 20 stops) can be resolved. The process is nonlinear and multifaceted, so an interruption by light nearly starts the adaptation process over again. Full adaptation is dependent on good blood flow; thus dark adaptation may be hampered by poor circulation, and vasoconstrictors like alcohol or tobacco.



Wikipedia

First two links are absolute must read.​

Digital Home Theatre Projectors FAQ's

The Contrast Ratio Game

Hometheatermag

 

[scrapbook]

Contrast ratio's have never mean't much other than to the stat junkies.

Most seem to think that a high contrast ratio means black blacks.

You can have a high contrast ratio on a TV without having particulary black blacks just because the white's are super white.

 

[ianh64]

LCD's actually have the highest contrast ratio of CRT and plasma's. But you wouldn't know it if you looked at it. So there is more than contrast ratio than meets the eye, gamma for instance.

It all depends on how you measure it, how you interpret it and who you give it to to publish your findings

The extremetech articles are very good articles if you ignore the US models and dated nature of the technology. They are written by a well respected industry expert who is independant, knows his stuff and has access to the kit required to make prudent scientific assessments. As such, they were reproduced over a period of 4 months (one month for each part I to IV - see table of contents at the bottom of each page) in the US technical publication Widescreen Review. A highly recommended read.

 

[Nielo TM]

Thx for the links. CRTs have theoretical infinite contrast ratios but that front glass limits it to below LCD, what a shame. What about CRT with anti-reflection coating.