A must read article from www.maximumpc.com !
Display Myths Shattered: How Monitor & HDTV Companies Cook Their Specs
Response Times: How Fast Is Fast Enough?
don’t pay much attention to a [LCD] manufacturer’s response time specs because they are so different from the real response time and motion blur that we have demonstrated here.
LCD published “Rise and Fall” (from black to white to black again) response time are much better than more subtle, “real life” response time (e.g. “gray to gray”)...
The underlying reason why higher refresh rates don’t mitigate blurring is that the true pixel response times [40 to 65ms] of [LCD] displays are considerably longer than the 60Hz [= 16ms cycle] video frame rate, so it doesn’t matter whether the screen refresh rate is 60Hz or 120Hz [or 400Hz], or whether the LED backlights are strobed off during the frame updating. Similarly, adjusting the electronic processing enhancements that some models offer – controls that are supposed to reduce motion blur [in fact by reducing pixel transition steepness via interpolation to hide slow and weird lcd responses] – only served to introduce objectionable contours, edges, and other artifacts onto moving objects without reducing the overall motion blur.
Their “Motion Blur: Visual Proof” image is very impressive.
my traduction:
Frame interpolation (and subsequent frame alterations) is crap (turn it off: is non curative on LCD, useless on plasma as they just don’t have any smearing with their instantaneous response time!) it gives a “video look” (+ a waxy look) on every sources (including films).
The fancier (e.g. 400Hz), newer the LCD is, the crappier the image is! A screen must be “high fidelity” (to what was recorded), adding non recorded interpolated fake frames (generated by a cheap processor) is low-fidelity, ugly and just plain wrong!
Interpolation and other processings are just done to hide LCD bad response time. Disable interpolation – if you can – then suffer LCD smear! Or better: use a plasma display (and don’t brag about saving the planet etc… yes LCD uses less power! ... so just watch less tv! ;-) even for sports and games: better (real image) blacks, no smear, and as for interpolation on very fast movements: your brain is doing a better job than a lowly processor…
n.b. the 600Hz refresh rates of new Panasonic plasma is just nonsense, to combat high LCD framerate claims with even more inflation; that’s sad (lies/stupidity race)! The image is still displayed at 60Hz but in 10 sub-fields! (10×60 = 600!)... Plasmas do NOT need >60Hz refresh rates to compensate for motion artifacts because they do not produce these motion artifacts!
Contrast Ratio, Ad Absurdum
Everybody should know that the maximum displayable real/natural contrast (in a real image) is not equal to the screen dynamic range (intensity-ratio between an all black vs all white image) also called Full On/Off contrast! But now manufacturers (especially for LCD) use “dynamic contrast” or even just “contrast instead” of “dynamic range”, inflating numbers…
Contrast-ratio specs are tremendously inflated. For the best LCDs, scientifically measured contrast ratios are actually between 1,500 and 2,000. But manufacturers almost never publish real contrast ratios anymore.
In their quest to quote ever-larger numbers, some manufacturers invented a completely meaningless spec called “dynamic contrast ratio” ... (Sometimes they don’t even bother mentioning the “dynamic” part). Sadly, all manufacturers are now forced to play this game, as consumers wouldn’t be interested in monitors and TVs that tout the true values. Meaningless contrast-ratio specs help substandard manufacturers by making their displays appear to be just as good as those from the best manufacturers, or even better, because the biggest liar wins.
see The Contrast Ratio Game (www.practical-home-theater-guide.com)
Color Gamut or Marketing Gambit?
Color gamut, which is the range of colors that a display can produce, is undoubtedly the most misunderstood and exploited spec
The color gamut that you want ... is the same color gamut that was used when the content you’re viewing was created. If a different gamut is employed, you’ll see different colors than you’re supposed to see.
Virtually all consumer content is created using industry standards that specify the exact color gamut to be used. For computers and digital cameras it’s sRGB. For digital HDTVs, it’s called ITU-R BT.709 (often referred to as Rec.709). Fortunately, both of these standards specify the same exact gamut.
Indeed, displays claiming more than 100 percent of the standard color gamut simply can’t show colors that aren’t in the original source image. Expanded gamuts are just gimmicks that make consumers think they’re getting something better.
Bit-Depth Misconceptions
First, remember that essentially all consumer content is 24-bit color. Thus, the source images have only 16.8 million colors, and the display can’t “invent” intensities and color combinations that don’t exist in the original.
n.b. Number of Colors Distinguishable by the Human Eye (at a fixed “aperture”): estimated between 100000 to 10 million! 24 bit encoding is way enough for us!
etc…
p.s. a little tear for SED ?