tu apie miltus ar apie tiltus? pas LCD pasvietimas veikia, pas plasma 
INDIVIDUALUS pikselis yra isjungiamas.

Jei lygintumei sukalibruotus LCD (tiek senu kobaltu lempo pasvietimu, tiek 
led pasvietimu) ir plazma - tiek vienos tiek kitos technologijos padarius 
egzempliorius imant - nesuprantu kaip tau 'matosi' juodesne lcd ... gal 
skaistis akis isgrauzia ir nematai spalvu/atspalviu?

Black Level is another oft-quoted but not-fully-understood metric which is a 
critical element of good image quality. The ability to create darker blacks 
allows a TV to have a higher contrast ratio, a term which will be explained 
shortly. The darker the blacks, the greater the appearance of depth and 
richness in the image shown. Black level is actually not particularly 
complex; it's just a measure of the level of brightness of a display when 
showing video black. It usually has as a very low luminance value, such as 
0.004 fL (0.013 cd/m2), but rarely reaches 0.0 cd/m2/fL (true black) because 
most HDTVs can't achieve this.

To confirm this for yourself, show a black screen on a typical LCD or plasma 
TV in a pitch black room, and you will still see some light coming from the 
screen, as the photo above demonstrates. So why isn't black on an HDTV 
actually equivalent to zero luminance, which is the total absence of light?

On an LCD-based display, black is simulated by the twisted crystals of the 
panel being completely shut, along with a polarized layer behind the 
crystals, to prevent light from the backlight filtering through when not 
required. Yet precisely because the backlight is always on, and the 
structure of the crystal array is not perfect, some amount of light will 
leak through the crystals and be seen - this is discussed further in the 
Screen Uniformity section. More recently, with the advent of local dimming 
backlighting, some LCD-based displays can switch off portions of their 
backlight to produce close to true black in parts of the image which require 
total darkness. Unfortunately this method isn't perfect, as there may be 
haloing of light around any brighter parts of the image.

On a plasma display, each pixel can be independently switched off to remove 
its light output, and since there is no backlight, in theory a plasma can 
produce true black. The reality is that each plasma cell has to be 
consistently pre-charged so that it can respond quickly enough when light 
output is required, giving plasma its extremely fast response time. The 
side-effect of this pre-charging is that there is always some residual glow 
in the pixels, and thus true black is usually not possible on a plasma. On 
average though, plasmas provide much darker black levels than LCDs.

It should be noted that what some consider the king of black levels, the 
traditional CRT TV, does not necessarily achieve perfect black either. A 
CRT's black is darker than either plasma or LCD, primarily because a CRT can 
simply have its electron beam avoid lighting up particular portions of the 
screen. However when displaying any scene containing brighter elements, some 
stray light may affect the dark areas of the screen. In other words, when a 
CRT is showing an all black screen, black levels are pretty much true black, 
but when displaying a normal scene containing a mix of brighter and darker 
elements, black levels on a CRT are not true black, and may be similar to or 
even worse than a plasma screen.


"Jonas Vingis"  wrote in message 
news:832762086401995248.120054jonas.vingis-kaimas.lt@news.omnitel.net...

"mooney" <mooney@moon.com> wrote:
> sapnuoji, arba kazka painioji konkreciai

Nei sapnuoju, nei painioju. Aš kalbėjau apie žiūrėjimą šviesoje.