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We go all technical about displays: introducing our brightness and contrast ratio tests

Display quality is climbing higher and higher on the priority list of everyone in the search for a new handset, so we thought it would only be fair if we give it more coverage in our reviews. That’s why we have just expanded the display section with another, more scientific test that should help you get a better impression of each unit.

Contrast ratio is the most important aspect of the performance of each display – deep blacks and bright colors is what everyone wants to have on their next handset. However manufacturers usually don’t list the exact specs and even if they do, they post misleading numbers that don’t reflect real-life performance accurately.

That’s why we decided it would be best if we started measuring that ourselves. From now on, you will see a new table in each of our reviews quoting the exact luminance levels (brightness) of white and black colors and the contrast ratio for every handset.

The test is done twice for each handset – first with the display brightness set to 50% and then with the brightness setting pushed all the way up.

Describing display performance in numbers would make it far easier to pick devices that suit you and compare different screens.

The higher contrast ratio is the difference between a washed-out display and a unit with punchy and rich colors. Notice that the contrast ratio is merely the difference between the brightest white and the darkest black colors a display can show at a given brightness setting. That means that a screen might have higher contrast ratio than a competitor, even if its overall brightness is lower as long the black levels are proportionally lower.

You should also keep in mind that we are testing the handsets in complete darkness, thus showing their optimal performance. When ambient light is present the display reflects a part of it raising the luminance levels of the blacks on screen and thus hurting the perceived contrast ratio.

If you want, you can also compare individual luminance readings to see which display is brighter.

An important note about AMOLEDs is due here. As AMOLED units have the ability to completely switch off individual pixels, their black level readings are 0, which gives them infinite contrast ratio in this test.

We will also be trying to introduce screen light reflectivity test in the near future to make display reviewing even more complete.

As usual, any thoughts on this new additions to our traditional reviewing routine will be appreciated.

Display test 50% brightness 100% brightness
Black, cd/m2 White, cd/m2 Contrast ratio Black, cd/m2 White, cd/m2 Contrast ratio
HTC Incredible S 0.18 162 908 0.31 275 880
iPhone 4 0.14 189 1341 0.39 483 1242
iPhone 3GS 0.84 134 160 2.51 504 201
Sony Ericsson Xperia Neo 0.05 68 1324 0.10 134 1295
Samsung Galaxy Ace 0.23 160 701 0.34 234 683
LG Optimus 2X 0.23 228 982 0.35 347 1001
Apple iPad 2 0.18 167 925 0.55 429 775
Apple iPad 0.21 178 834 0.53 410 776


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