Hdtv incompatibility Ratio Explained - How to select the Best Lcd Tv - Dynamic incompatibility Ratio

Introduction to divergence Ratio: divergence ratio (Cr) is a parameter stated for all Hdtvs, but is often very misunderstood. Before the flat panel revolution, Crt televisions never advertised this figure. The respond is straightforward and lies in the technology. Crts use an electron beam to illuminate phosphors on the screen and originate a picture. If the electron beam is switched off, that section of the screen turns absolutely black. White areas would max out the electron beam. Theoretically, old school Tvs had an infinite Cr, and blacks were displayed to perfection.

Lcd Hdtv divergence Ratio: modern Lcd Tvs use twisted nematic crystals to originate the picture. What does that mean? Quite naturally it is the same as using horizontal window blinds to allow or block light. Each tiny cell on your monitor has sub cells with red, green and blue polarizers. Each cell is controlled by a transistor (Tft is Thin Film Transistor) and thus the perceived intensity of the lively backlight can be controlled. To originate black, the cell is ordered fully shut. The problem is (as with the horizontal blinds) that some light will always bleed straight through the crystals. This undesirable consequent produces blacks that are somewhat gray and even colors that don't seem to pop. Inexpensive, deal brand Lcds may suffer from this problem. Most citizen any way do not observation this issue until it is pointed out to them.

Cr Measurement: Lcd makers are free to portion Cr in any way that they please. There is no current acceptable and it is incorrect to correlate divergence ratio between manufactures. Basically Cr is measured by taking a light intensity reading of the brightest area vs the darkest area on the screen. If the brightest area of the screen is 2500, and the darkest area 10, you have a 250:1 Cr. Of course, how you set brightness, contrast, etc. On the Tv can have a big impact on these measurements. Also, equipment calibration and setup can have a bearing. Finally, your eyes will realize divergence differently based on ambient light settings. Do you ever wonder why movies turn down the lights? That should give you a big clue. Also, do not buy a glossy screen if there is ambient light in the room. If you are going to be watching Tv in a room with windows and sunlight, opt for a matte screen.

Dynamic Cr: Despite the large divergence ratio numbers advertised, bare panels may have Cr figures in the 1000:1 range. However, by manipulating back light intensity based on actual scenery, Tv makers can get six and seven outline divergence ratio measurements. For example, why run the back light on full intensity when you are seeing at the night sky with stars? Dim the bulb, and less light will bleed straight through the black area giving the illusion of a much higher divergence ratio. Practically all Lcd Tvs sold now have dynamic divergence ratio. When you purchase a Tv, look for divergence ratios above 40000:1 and a dynamic Cr number. One last word, dynamic divergence percentage isn't a excellent solution, sometimes you have a very dark scene with a small portion of the screen very lively (like a moon lit night). A scene like that could make the divergence between a great Tv and a mediocre one.

Led Lighting: A new develop in technology uses clusters of Leds to illuminate the screen instead of a particular lamp running the top distance of the Tv. The Samsung Un55C7000 is an example of such a Tv. These Tvs can originate total blackness in unavoidable areas of the screen, theoretically creating a near infinite (or seven figure) divergence ratio. Because the Cr is so high, these Tvs can originate life like 3D images that appear to lift off the screen!

What should you think when buying an Hdtv? Do not make divergence ratio a major purchasing point. As a rule, look at divergence ratios in factors of ten. A Tv with a 600K:1 Cr is probably good than one with a 60K:1. Do not naturally select a Tv because the Cr is a few thousand higher. Read Reviews and pay attentiveness to tag words like black and shadow detail, color vibrancy and even descriptions on how games look. These are the real factors in determining ultimate shadow information and Lcd performance.