Display
With displays, it is easy to get caught in the hype as technology buzzwords are meant to grab your attention rather than describe the actual screen quality. Super AMOLED, HD-IPS, Super LCD, Retina IPS and whatnot, each claim to offer the best image quality around, but usually find it unnecessary to provide specific numbers, which would make technologies easier to compare.
On the rare occasions that display specs are actually quoted, the numbers are purposely chosen to be misleading and make the real-life performance seem much better than it really is. Which is where our first test comes in.
Perhaps the most important factor when it comes to screen quality is contrast ratio. Contrast ratio is the measure of the dynamic range of the luminance of the display, essentially describing how much darker the deepest blacks are than the brightest whites. A display with a good contrast ratio is able to show richer, more vibrant still images and videos that come to life.
The brightness of a given object is measured in candela (cd), which is the scientific unit for luminance. One candela--which stands for candle in Latin--is the equivalent of the light intensity of one candle as perceived by the human eye. For displays, light is measured per square meter of surface area (cd/m2), which is sometimes also referred to as Nits (nt).
The contrast ratio itself is determined by measuring the cd/m2 of a pure white screen, and dividing it by the cd/m2 of a pure black screen (note that on an LCD a pure black screen is not the same as a screen which is turned off, because even black pixels emit some light). So, a display which has 100 cd/m2 of whites and 1 cd/m2 of blacks will have a contrast ratio of about 100:1.
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 an infinite contrast ratio under the testing conditions.
When we measure we take two readings off each device - first with the display brightness set to 50% and then with the brightness setting pushed all the way up. We test the handsets in complete darkness, because when ambient light is present, the luminance levels of the blacks displayed goes up, and affects the perceived contrast ratio.
Contrast ratio is very heavily influenced by the black levels of a display. While a brighter display would normally have an advantage, it will usually be unable to compensate for insufficiently deep blacks.
Sunlight legibility
While having a good quality display is important, the reflectivity of the screen is not to be neglected. After all, you rarely use your smartphone in complete darkness, so there's little use of having a premium screen that turns into a mirror in bright environments.
Camera compare tools
Our Photo/Video Compare tools are designed to give you an idea of how well a given camera performs in real-life conditions, and how it stacks up against its peers. Being able to look at the images produced by up to three devices side-by-side is immensely helpful in figuring out how good a given cameraphone actually is.
While we still take "real-life" outdoor photos with all of the devices we review (which you can check out in the reviews themselves), those are frequently at the mercy of the weather, and not as easy to reproduce all year round as we would like. That's why we designed this test to be as objective as possible - all samples are taken in controlled conditions in our studio, at the same time of day under the same lighting.
The tools allow you to judge a cameraphone's performance not only in terms of resolved detail, but also image processing (noise reduction, sharpening) and camera lens distortion.
With the Photo Compare Tool, you'll be able to choose from one of three different charts, and up to three devices to compare. Each device is listed with its native resolution, but you can scale all the sample photos to see how cameras of different resolutions compare against each other. A good 8MP camera, for instance, will typically be sharper when scaled down to 5MP, but sometimes the lower-res camera will win out when you equalize the resolution.
Our Video Compare Tool allows you to compare still frames taken from videos captured with the phone. We've set up two test scenarios: one under normal lighting conditions and one under low-light to give you an idea of how the handsets fare in different environments. The motion in the Ferris wheels will allow you to see how much fine detail survives the post-processing, as well as the compression levels, noise levels and so on. Of course, a still frame doesn't tell the whole story - there's also framerate, rolling shutter effects and other considerations which the tool doesn't cover, but it's still a good starting point.
We also have our resolution chart shot on video. It shows how much of the available resolution is retained when shooting video. Just like in the Photo Compare Tool, the three charts are accessed by clicking on their names below the main sample image. Other tested devices are listed alongside their natively supported video recording resolution.
For both tools, at the bottom of each device selection field you'll find a list of reference cameras available, which allow you to see how a particular cameraphone compares to a professional DSLR unit, such as our in-house Canon EOS 5D Mark II. You'd be surprised at how well certain cameraphones stack up against these heavy hitters.
Keep in mind that only devices reviewed after November 2010 will have compare tests available, and only cameras with 720p video recording and higher will have video compare.
