A touchscreen is the central feature of any smartphone these days, but
not many handset displays actually manage to reproduce colours
accurately. Let's take a look at how a few of the latest models compare.
Whether watching a video, surfing the web, sending photos to your
friends or simply making a call, the touchscreen is a key feature in any
modern multimedia-enabled smartphone—along with the processor, of
course. Mobile phone screens keep getting bigger and bigger in size, and
contrast has improved over time to reach a respectable level in both
high-end and entry-level handsets. Smartphone screen viewing angles are
usually wide enough keep things easy for users to see, but colour
fidelity still tends to vary considerably from one handset to another.
Bright, eye-catching colours are evidently still supposed to appeal to unsavvy consumers. Just take a walk around your local TV shop and you'll see the extent to which manufacturers use gaudy 'in store' colour settings to grab our attention. The same is true of certain smartphone screens, with colours that are so eye-popping they end up bordering on fluorescent. Compared with older smartphones, current screens may have been toned down to gain a certain amount of neutrality, but colour fidelity can still be quite different from one model to another. That's something we see every week when we measure the average Delta E of the smartphones we review.
Delta E measures colour fidelity. The Delta E should be as close to zero as possible—the lower the Delta E, the more accurately colours are reproduced. For smartphones, a good Delta E should be less than or equal to three. Past three, the higher the reading gets, the less accurate onscreen colours will be.
Bright, eye-catching colours are evidently still supposed to appeal to unsavvy consumers. Just take a walk around your local TV shop and you'll see the extent to which manufacturers use gaudy 'in store' colour settings to grab our attention. The same is true of certain smartphone screens, with colours that are so eye-popping they end up bordering on fluorescent. Compared with older smartphones, current screens may have been toned down to gain a certain amount of neutrality, but colour fidelity can still be quite different from one model to another. That's something we see every week when we measure the average Delta E of the smartphones we review.
Delta E measures colour fidelity. The Delta E should be as close to zero as possible—the lower the Delta E, the more accurately colours are reproduced. For smartphones, a good Delta E should be less than or equal to three. Past three, the higher the reading gets, the less accurate onscreen colours will be.
Some handsets, like the Galaxy S2 with its Super AMOLED screen, for
example, have several picture modes (three, in fact) with different
screen settings that in turn make the Delta E vary. Plus, the original
black version of the phone has a Delta E of almost 15, whereas the white
model that arrived later pushed that down to 6.8. That's slightly
better than the older Galaxy S. Things are therefore clearly moving in
the right direction, as OLED screens seem to be getting more neutral
with their colour reproduction—although, to be honest, they couldn't get
much worse!
The Apple iPhone 4 and iPhone 4S have very similar Delta E readings. Still, our sensor measured colours that were more accurate in the iPhone 4 than the 4S, which was released later. Plus, the 3GS—which doesn't have a Retina display like the more recent iPhones—does a little better with colour reproduction than the two more recent phones. The LCD iPhone screens therefore haven't got more accurate over time. We can only hope that the iPhone 5 (which is rumoured to have a 4-inch screen) does a better job.
Like with TVs, several types of screen technology can be found in today's smartphones. Apple has its own Retina technology, Samsung uses AMOLED (along with Nokia and HTC) and Super AMOLED, while Sony has borrowed the LCD technology from its Bravia TVs. Basically, all these types of technology give good overall results, with high contrast—even infinite contrast with AMOLED—and all have seen colour fidelity improve. However, there's still some way to go to get the sacred Delta E of three or under. But these high-tech, high-resolution screens are no longer reserved for top-of-the-range mobiles, as they're increasingly trickling down into mid-range models.
The Apple iPhone 4 and iPhone 4S have very similar Delta E readings. Still, our sensor measured colours that were more accurate in the iPhone 4 than the 4S, which was released later. Plus, the 3GS—which doesn't have a Retina display like the more recent iPhones—does a little better with colour reproduction than the two more recent phones. The LCD iPhone screens therefore haven't got more accurate over time. We can only hope that the iPhone 5 (which is rumoured to have a 4-inch screen) does a better job.
Like with TVs, several types of screen technology can be found in today's smartphones. Apple has its own Retina technology, Samsung uses AMOLED (along with Nokia and HTC) and Super AMOLED, while Sony has borrowed the LCD technology from its Bravia TVs. Basically, all these types of technology give good overall results, with high contrast—even infinite contrast with AMOLED—and all have seen colour fidelity improve. However, there's still some way to go to get the sacred Delta E of three or under. But these high-tech, high-resolution screens are no longer reserved for top-of-the-range mobiles, as they're increasingly trickling down into mid-range models.
LCD vs AMOLED: Which Gives a More Accurate Image?
If we exclude the original, black Samsung Galaxy S2, tested at its
initial time of release without using the various colour profiles (which
we then tested in the updated white version), LCD and AMOLED technology
work out at the following averages:
Perhaps because the technology is older and better mastered, LCD screens
tend to give slightly more accurate results than AMOLED screens—with
colours that are 20% more accurate, on average. However, there's hope
for AMOLED yet, as the HTC One S AMOLED screen is almost as accurate as the LCD display in the One X. Almost ...
Let's hope that Samsung and LG will pay closer attention to the colour settings in their upcoming OLED TVs!
Let's hope that Samsung and LG will pay closer attention to the colour settings in their upcoming OLED TVs!
Where Next?
Like monitors 10 years ago, TVs five years ago and like laptop screens
today, colour fidelity isn't at the top of smartphone manufacturers'
lists of priorities. But they're starting to think about it, and
starting to change things slowly but surely.
There's little doubt that sometime in the not too distant future, all mobiles will display accurate colours out of the box, as is the case with most monitors and TVs these days (in Cinema/Movie mode).
We very distinctly remember monitor and TV makers telling us our colour readings were pretty much pointless, as no-one cared about accurate colours. Today, however, no manufacturer worth its salt would launch a poorly calibrated TV or monitor. It just wouldn't be acceptable. Maybe soon it won't be for smartphones either ...
There's little doubt that sometime in the not too distant future, all mobiles will display accurate colours out of the box, as is the case with most monitors and TVs these days (in Cinema/Movie mode).
We very distinctly remember monitor and TV makers telling us our colour readings were pretty much pointless, as no-one cared about accurate colours. Today, however, no manufacturer worth its salt would launch a poorly calibrated TV or monitor. It just wouldn't be acceptable. Maybe soon it won't be for smartphones either ...
