Ulefone Armor 21 Review

Display

Ulefone Armor 21 has the same display as the previous Armor models - a 6.58-inch IPS unit with an FHD+ resolution (1080 x 2408) and a 120Hz refresh rate. The latter can be manually set to 60Hz or 90Hz from the Display settings. You can also opt for automated mode so the device changes the refresh rate depending on the content displayed on the screen. Other display settings include adaptive brightness, night light, lock screen, LED notification light, color mode, and others. The Home settings which are accessed from the Widgets menu are also placed under the Display settings. The display of the Armor 21 is very bright, comfortable to use outdoors, and fluent to work with. Our usual measurements of the white and black luminance, static contrast ratio, and color temperature of the display are published below. If you follow our smartphone reviews, you already know that for a more realistic result, we make two different measurements - on a single frame that displays 50% white and 50% black and on two separate frames displaying a fully white and a fully black screen.

A single frame, 50% white / 50% black

Brightness	White luminance	Black luminance	Contrast	Color temperature
100 %	390.461 cd/m2	0.249 cd/m2	1568 : 1	10600
0 %	1.23 cd/m2	0.000 cd/m2	-	10698 K

Two separate black and white frames

Brightness	White luminance	Black luminance	Contrast	Color temperature
100 %	557.301 cd/m2	0.347 cd/m2	1606 : 1	10441 K
0 %	1.974 cd/m2	0.000 cd/m2	-	10620 K

The maximum brightness of the display of the Armor 21 we have is 557.301 cd/m² measured from the center on a fully white screen. This brightness is achieved during the two separate black and white frames measurement. In the other type of measurement on a 50% white and a 50% black screen, we measured a white luminance of 390.461 cd/m². There's a noticeable difference between the two but the contrast ratios from both are almost identical - around the 1600:1 level because the black luminance levels are higher on the first and lower on the second type of measurement. The temperature of the white point is very high - around 10600 K.

Position	Left	Center	Right
Top	485.972 cd/m2 / 9745 K	487.529 cd/m2 / 9912 K	494.512 cd/m2 / 10218 K
Center	512.635 cd/m2 / 10483 K	552.617 cd/m2 / 10607 K	537.393 cd/m2 / 10675 K
Bottom	499.806 cd/m2 / 10728 K	497.641 cd/m2 / 10883 K	505.891 cd/m2 / 11164 K

Our brightness uniformity measurement shows that the display of the Armor 21 delivers different brightness levels at different points of measurement. The top one-third of the screen has an average brightness of 490 nits and a temperature of the white point of around 10000 K. The middle one-third has an average brightness of around 550 nits and a temperature of the white point of around 10600 K. Finally, the bottom one-third has an average brightness of 500 nits and the temperature of the white point at this tier nears 11000 K. The CIE diagram shows that the display covers more than 100% of the sRGB color space. The coverage of the blues, cyans, and magentas is almost perfect. However, the coverage of the reds, oranges, and yellows toward greens is not. You will get puncher greens, yellows, and orange hues with subtler reds. The display panel has a traditional vertical striped RGB subpixel arrangement.