Reaction time
A car moves from left to right at high speed.
Movement isn’t perfectly fluid. Depending on its speed, the car is shown in several successive positions. If the car goes very fast, the positions are very close and the eye perceives a flowing movement.
perfect monitor 
monitor with two afterglow imagesA monitor without ghosting effects would have previous images completely fading away when a new one appears. This is the theory and in practice, it's often not the case as images progressively fade. Sometimes up to 5 afterglow images remain on the monitor and represent the visible white trail behind objects. Some monitors have strong overdrives in addition to image anticipation algorithms. In this case, an image can appear in front of the main object, creating a white halo ahead of objects in motion.
We capture afterglow with a camera at a shutter speed of 1/1000 s for an LCD. We take 50 pictures per test. We then can see a monitor’s ghosting effects, or the car’s position in the entire process from the moment where it is at the maximum level, up until the moment when the next image is about to be drawn and when the previous images are the least visible.
Out of the nine monitors tested in this survey, eight have a response time of 5 ms. Panel origins aren't the same and some are manufactured by Samsung, others by AU-Optronics and CMO. It might sound a bit surprising, but regardless of the manufacturer there is no difference in afterglow and they are all strictly identical. With two monitors in clone mode or with our camera it was impossible to single out any one with the human eye.
The ninth screen, the Samsung 226BW, has a Samsung 2ms panel. This made a difference and the result was clearly better.
Rather than one long page of identical images, we chose to oppose all 5ms rendering with the 2ms:
Here are the two extreme states with each monitor as afterglow oscillates.
TN 5 ms : Acer, Dell...
TN 2 ms : Samsung SyncMaster 226BWThe difference in games is obvious and the 226BW is much better than the others, especially in FPS games.
This superior reaction time is also of interest for videos. Tracking shots are better rendered and fast movements are less subject to creating multiple images of the same character on the screen.
