Decent SDR peak brightness overall, but the brightness varies a lot depending on the average brightness of the content shown. When bright scenes are shown, like our real scene and 100% white window tests, the TV dims considerably; however when a 2% or 10% window is displayed the TV gets very bright initially, then it cycles between bright and dim approximately every 30 seconds. This drastic brightness difference depending on the content thankfully doesn't occur in PC mode, so white web pages won't be dimmed.

Local Dimming was set to High for these tests. Other values weren't as bright.

The above results are for Movie mode calibrated to 6500k; in Dynamic mode many test patterns are brighter, as shown in the table below. Note that Dynamic mode isn't as true to the source material as Movie mode because it uses different settings, such as a cooler color temperature.

Real Scene: 366 cd/m2

Window size Peak (cd/m2) Sustained (cd/m2) 2% 389 368 10% 1189 622 25% 450 450 50% 383 380 100% 380 380

Update 03/15/2017: We bought a second unit and the peak brightness is in the same ballpark. See the additional review notes for more information.

Update 05/12/2017: The TV has been retested with the latest firmware (1017.1) and it's slightly brighter than before. The scores have been updated, and a plot of the new brightness is shown here.

Update 06/22/2017: Samsung got back to us regarding their investigation. See their statement here.

Update 07/05/2017: We improved the TV's brightness by realigning the light guide plates by dropping the TV, as shown in this video. The brightness increased a bit, by 30-100 cd/m², at the cost of worse uniformity. The brightness scores have been updated, and an updated brightness plot is shown here.