Understanding LCD Contrast Ratio

You’re thinking about buying the latest LCD HDTV and wondering what’s the latest offering on contrast ratio all about.Manufacturers are heavily advertising new LCD contrast ratio figures ranging from hundreds to thousands to one but you can’t make any sense of the numbers. How are these numbers calculated and how can they affect picture quality?

Contrast describes the difference or dissimilarities between elements and encompasses may aspects of our lives. It’s in the yin vs yang, white vs black, Mozart vs Metalica, 0 vs 1 etc. Contrast appreciation is not only an aesthetic concept, but a primal instinct honed through centuries of struggle for survival. Our caveman ancestors have long depended on our visual contrast sensitivity to spot predator and prey and come out top of the food chain.

There are basically two types of LCD contrast ratios, but the most common figure stated by manufacturers is the dynamic or sequential contrast ratio. It is measured by dividing the luminance (brightness) of peak white at one time by the luminance of reference black at another. Two points to take home here; higher values are better. And for the same amount of peak brightness, higher LCD contrast ratios generally indicate better black levels. But here’s the rub; there is no standard way to measure dynamic ratios and so contrast ratios are rarely comparable between manufacturers.

Simultaneous, or static contrast ratio measures the ratio between peak white and reference black reproduced in a single scene using a ANSI checkerboard pattern. This should give a better indication of the display’s performance. For many reasons (room gain, display flare, design etc), the static ANSI contrast ratio normally has a lower value than dynamic ones and therefore won’t be a favourite spec with manufacturers.









ANSI checkerboard pattern

The contrast ratios above deal primarily with white and black luminance only, but what about the other shades of colour in between them?  Image contrast perception is also affected by the ratio of colour luminance between black and white. In the example below, the two pictures have the same white and black luminance (same contrast ratio) but the left picture looks more contrasty because of different `gamma’ curves.

In summary, higher LCD contrast ratio, whether ANSI or dynamic, can have the following benefits: better blacks, higher brightness, wider greyscale and colour range, better shadow detail definition and increased perceived sharpness. Although this ultimately depends on your TV design, you should do the following to maximize your contrast ratio on your LCD whenever possible.

1) Brightness control should be set at the correct black level level. Set too high and you will reduce the contrast ratio and wash out colours at the darker end.
2) Contrast control (white level) should be maximized to comfortable levels without losing detail in highlights.
3) Ambient light should be reduced as far as possible because contrast ratios are lowered in its presence.
4) LCD contrast ratio drops considerably after a certain viewing angle, so make sure you stay in the sweet spot.
5) If you have a gamma control, experiment with it and find the picture with the highest `contrast’. This setting will change depending on your ambient light conditions.

Source : http://www.hdtvtest.co.uk/news/understanding-lcd-contrast-ratio-2007032940.htm


Info Tambahan (dari berbagai forum) :

Contrast Ratio :

Best Answer - Chosen by Asker
Contrast ratio is the difference in brightness between blacks and whites. For example,
500:1 is staying that Whites are 500 times brighter than Blacks. What does this means in layman terms?
This means bright whites, darker blacks and everything in-between is more vibrant and accurate.

Higher the contrast ratio, the better the colors you will have on your image. This spec is unrelated to clarity,
resolution and refresh rate. It is specifically telling you about color quality.

Picture refresh rate would be response time. You will see the term in ms. 30ms is slow. Good LCD response time is under 10ms.
Excellent is under 5ms.

Resolution can be seen in computer or video terms. Computer terms would be two values, such as 1920x1080.
Video terms would be 480p, 720p, 1080p. The correlation between the two types of terms is the last value.
1920x1080 is the same as 1080p. 1280x720 is the same as 720p.

Sebagai penyegar, contrast ratio adalah angka yang mewakili tingkat kejernihan gambar yang akan ditampilkan.
Semakin tinggi contrast ratio, akan semakin jernih/kontras gambar yang Anda lihat.

Tidak ada standard baku untuk contrast ratio. Dengan kata lain, contrast ratio 4000:1 dari merek A
belum tentu lebih baik dari contrast ratio 1000:1 dari merek B.
Demikian pula halnya dengan jumlah warna yang berjuta-juta, belum tentu dapat menghasilkan gambar yang lebih baik dari merek tv lainnya.
Lain halnya dengan jumlah pixel yang memiliki standard dunia yang sama, artinya 1024x1024 pixel merek A sama dengan 1024x1024 pixel merek B.

Semakin besar semakin bagus...
Berarti makin bright layarnya...
Jadi warna bisa lebih keluar...
Tapi ati-ati sama informasi contrast ratio yang tinggi...
Masing-masing pabrikan biasanya mempunyai perhitungan sendiri untuk menentukan contrast ratio produk mereka...
Saran : test pake mata sendiri bagus apa tidak tampilan gambarnya... :D

Kontras makin besar nyaman untuk digunakan di ruangan terbuka seperti ruangan tamu ataupun mal.
Sedangkan kontras ratio rendah akan ada efek sebaliknya. Para produsen TV/LCD saling berlomba untuk dapat mengeluarkan
produk FPD dengan warna sebagus warna aslinya. Panduan untuk memilih sebuah FPD adalah dengan membedakan warna
yg dihasilkan sebuah FDP dengan subjek aslinya. Kalau untuk resolusi, memang ada standardnya yg tertinggi saat ini di
pasaran adalah WXGA jika memang ingin digunakan untuk sebuah monitor PC namun untuk signal video yg tertinggi adalah HDTV (1080i).
Keduanya sangatlah berbeda.