Reaction test
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 3 ghost 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 fade progressively. 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.
With CRTs we captured afterglow with a camera at a shutter speed of 1/60 seconds as compared to 1/1000 s for an LCD. We take 50 pictures per test. We then can see a monitor’s ghosting effects, or all the car’s position in the entire process. The most important image is the one on the left, the better one. It will be the most displayed on the monitor, while the one on the right is in transition.
Here are the two extreme states with each monitor as afterglow oscillates.
S-PVA 6 ms : Dell 2407WFP
S-PVA 6 ms : Samsung SyncMaster 244TThis test isn´t really scientific, but from our point of view it is closer to reality or what we see in games. It’s much better than an oscilloscope response time measurement. Nevertheless, the pictures published above are flattering. They represent precisely what the monitor is capable of, but that isn´t what our eyes exactly see. Our sight is subject to a phenomenon of visual latency. Nowadays, the largest part of afterglow perceived on monitors no longer comes from monitors but from our eyes. This is the reason why the BFI and MPA technologies unveiled by BenQ and Samsung at CeBIT this year are so promising. They both introduced a visual screening, a black or grey area in motion that will "clean" our eyes from previous images. This principle directly comes from CRTs.
This test reflects the monitor’s pure reaction time and allows us to compare it to others. We’ve included the previous Samsung SM 242MP equipped with the previous S-PVA 16 ms panel. This is the same panel as the Dell 2405FPW.
This test shows the progresses made by the new Samsung panel. You have to count the afterglow image to see it. The new Dell and Samsung produce the same results:
This small "1" in the best image makes a big difference for the monitor behaviour. For the 16ms panel, the afterglow is very strong and bothersome. For the 6ms, it has considerably diminished to come back to a much more reasonable level, comparable to TN and MVA 8 ms panels:
P-MVA 8ms : ViewSonic VX2025wm
