A – S : comparison of panel homogeneity
The A panels are reputed to have a backlighting problem on the lower part of the screen, or more precisely, a slight white halo. Before looking into this, we wanted to go through an intermediary step of measuring brightness homogeneity on the screen. Is it the same everywhere, or at least are differences modest ?
As a reminder, perfectly homogenous panels don’t exist. In the best case, on the Dell 27 inch, for example, we measured variations of 12% from one point to another. In the worst case, on some older generation Apple and Dell screens, this figure went up to 50% ! More commonly, average screens have differences of around 30 %.
On our two screens, we measured maximum gaps of:
- 21 % on the 226BW A series,
- 30 % on the 226BW S series.
Panel A, 1 point. Panel A, one point.
This is illustrated in these images:
Samsung 226BW A
Samsung 226BW SDon’t give in to your first impressions as the first screens has lesser differences. At the same time, the 226BW S seems to do better in this area, because its defects are more homogenous. In both cases, the center is brighter than the rest and brightness diminishes near the edges. On the S it’s progressive, while on the A, this phenomenon is more pronounced on the left of the monitor.
Finally, the average difference by area is 5.8 % for the A versus 6.1% for the S. If we take all points where measurements were taken and compared them to the average brightness, the maximum gaps for the A version is from -9% to +12% or the 21 % max from above.
On the S version, we go from a more extreme -13% to +17% or a max variation of 30%. This result is consistent with other screens, but not as good as the “A” s results.
Again we remind you to take these figures into perspective, because they depend on a number of factors. There is of course the quality of the product, but also transport.
Now, does the 226BW A have a bright white halo on the lower part of the screen ?
We go to a dark room, and with the help of our probe set both monitors to a brightness of 150 cd/m².
Here are the two screens shot in the dark with an exposure time of 1/6 second :
Samsung 226BW A
Samsung 226BW SThe two screens have the same defect of a little white halo-very subtle-that you may notice on black images. If we wanted to split hairs, we could say that that of the A is slightly more visible. For us the existence of this little halo is overshadowed by this screen’s nice depth in black.
