Samsung details its new Galaxy S5 display: the brightest, most efficient OLED screen to date can hit 698 nits

First off, they confirm the so-called "Diamond" structure for the arrangement of the subpixels, an alternative to the standard RGB matrix arrangement. This structure seems is an offshoot of the PenTile matrix arrangement, but its advantage is an improved fill factor, which correlates better to the efficiency of the different OLED materials used to achieve the basic colors. Samsung says that the Diamond Pixel arrangement in its AMOLED panels is actually better than the PenTile of yesteryear, as it reduces aliasing and artifacts. Still, the number of green subpixels in the diamond matrix is as high as it would be in a regular RGB stripe configuration, for instance, while the red and blue subpixels are 50% less. They are much larger, though, and with a diamond shape, while the numerous small green subpixels are oval. 

This rendering scheme has allowed Samsung to achieve the same 1080p resolution as displays with a normal RGB stripe matrix, but with two thirds of the subpixel count. The overwhelming number of green subpixels is due to the fact that green is the longest-lasting and most efficient OLED emitter, while the red, and especially blue, are more taxing on the battery, and have a shorter lifespan. Now you know why even in the Cinema mode, which has been measured to be the closest to the standard sRGB color gamut, the green pulls towards oversaturation - there are just too many green subpixels in the Full HD Super AMOLED panels. Long story short, in terms of color representation we can't expect the screen on the Galaxy S5 to differ much from the one on the Note 3 and the S4, which share the same Diamond Pixel arrangement.

The big improvements are in brightness and power efficiency, though, reiterates Samsung. OLED displays don't have backlighting, as LCDs do, and only count on the light emitted by the organic LEDs in their structure. Thus, their maximum brightness levels are usually lower than those of the best LCDs out there. As you can see in the chart below, however, the 5.1" Galaxy S5 display is 22% brighter than the panel on the Galaxy S4, and 13% brighter than the Note 3. Those 351 nits might not sound much compared to, say, the 500+ nits of the iPhone 5s screen, but here Samsung is giving an example for the typical ambient lighting levels in your home or office, for instance, where LCDs hit similar values. 

During the Galaxy S5 announcement, Samsung bragged that it can easily hit 500 nits, which is a remarkable feat for a Super AMOLED screen. Today it clarified the peak brightness levels further, saying that in  further in certain high ambient lighting situations - for example, when the summer sun outside is shining directly on the display - they've measured burst levels of 698 nits, while the S5 hits 475 nits on the regular outside. This is the highest brightness level achieved by a mobile OLED panel so far, as only some Nokia Lumias manage to hit 600 nits in those circumstances, so kudos to Samsung here. 

Moreover, the good OLED panels are covered with elaborate low-reflectivity coatings, which serves to minimize those pesky mirror reflections, so their visibility outdoor is on par with much brighter screens. Samsung touts 4.5% reflectivity ratio for the S5, which is amongst the lowest measured on a mobile screen so far, making the Galaxy S5 panel an excellent screen for outdoor usage. Last but not least in the brightness department, the minimum luminance levels are just 2 nits now, which makes the phone more comfortable to use when you are lying in bed in complete darkness, and get a message, for instance. The human eye starts perceiving glare and discomfort in those situations at levels as low as 3-5 nits, says Samsung, so it tried to go even below that with the minimum brightness level on the S5.

In addition, the improved organic materials used by the company to make the new S5 panel led to 27% reduction in its power consumption rates, compared to previous Super AMOLED editions, like the one on the S4, as well as measured up to 1080p LCD screens. This allowed Samsung to eke out about a third longer battery life from the S4 to the S5, while bumping the battery capacity only slightly. 

When we combine that power-sipping display with the new Ultra Power Saving mode on the S5, it should be ranking among the best, but we'll save the verdict for when we do our own battery test. For now, it seems that with the Galaxy S5, Samsung has indeed managed to make its best mobile screen with OLED technology to date.

source: SamsungDisplay