Response Time and Hertz
On earlier LCD panels, “ghosting” was common. This was because the panel hadn’t “cleared” the previous image. So, when Virender Sehwag whacked a ball into the crowd, the motion on the screen would “shudder”.
Most mid-range TVs have solved this issue with software that allows faster transition periods, but even then, when there is fast action in darker-light conditions (imagine the car chase through the tunnel in Quantum of Solace) you can make out the “shudder”. This is what is called the response time.
High-end LCD panels deal with this problem by moving to a higher hertz rate, meaning the number of times the screen shows a new image. So, instead of 60-75 hertz screens, there are 100 hertz screens.
LCD panels nowadays have several inputs but you need to see what it comes with. Make sure that your panel not only has enough HDMI inputs, but also Component HD and at least two RCA composite video inputs (the red, white and yellow connectors from set-top boxes and DVD players). Crucially, since LCD panels allow computer connectivity, check if the panel has a VGA adaptor as well. Pricier panels usually have more connectors.
USB and Bluetooth
While most LCD panels have USB support, the more expensive models add DivX movie-playing support in addition to playing back pictures and music. Some highend panels today come with Bluetooth and Wi-Fi support, as well as memory card readers. Check the specifications carefully.
Contrast Ratio measures the difference between the blackest and the whitest that an LCD panel can display. Standard screens have contrast ratios of between 40,000:1 to 50,000:1. There are no auditing bodies that conduct this test so the manufacturers claim is all you have to go on. Also the “claimed” contrast ratio is achieved in “lab” (dark room) conditions. LCD screens use LED lamps at the corners to stimulate lighting.
However, the latest and high-end LCD screens use LED strips for constant and better colours and higher contrast ratios of 100,000:1. Coupled with high refresh rates and better processing power, this means far superior image quality.