Display

Smartphone displays have rapidly improved at every single price point. Inexpensive smartphones often compromised on display quality, which ended up hurting much of the overall experience. However, even inexpensive smartphones now ship with IPS displays and high enough resolutions to render text without overwhelming aliasing.

The Lumia 640 has a 5" 1280x720 IPS display. At 294 pixels per inch, it’s fairly sharp for a phone of this price. It’s obviously not some 2560x1440 flagship phone, but I never felt like text appeared fuzzy or highly aliased. To evaluated the aspects of display quality beyond what you’ll see on a spec sheet we turn to our standard smartphone display tests. As always, measurements are performed with X-Rite's i1Pro 2 spectrophotometer and SpectraCal's CalMAN 5 software, with the exception of contrast measurements which are done with an i1Display Pro colorimeter.

Display - Max Brightness

Display - Black Levels

Display - Contrast Ratio

437 nits is a fairly good result for peak brightness. It’s not quite as high as the 500 and 600nit displays that you’ll see on flagship phones, but it’s noticeably higher than many other devices at this price point. The contrast is also pretty good. While the black level isn’t even close to the lowest we’ve seen, when you consider that many devices use CABC to cheat on contrast it’s actually a relatively good result.

Display - White Point

Display - Grayscale Accuracy

The greyscale results on the Lumia 640 are exceptional. RGB balance is great at every shade of grey, with only a very slight shift toward blue. All of the errors will only be visible if you compare static images with a reference monitor. There’s not much more to be said, as the greyscale accuracy on this display is essentially perfect.

Display - Saturation Accuracy

The next test examines saturations of primary and secondary colors on the display in increments of 20%. In this test the Lumia 640 does very well. There are definitely some issues with blue and magenta, and the fact that cyan maxes out at 80% saturation, but the overall accuracy is very good.

Display - GMB Accuracy

The final display benchmark is the Gretag MacBeth ColorChecker test. This test examines colors that are commonly found in the real world, and it’s the best benchmark of display color rendition. A display can hit its saturation targets accurately but fail to reproduce these color mixtures properly.

Fortunately, the Lumia 640 suffers from no such issues. Most of the colors are reproduced with a high degree of accuracy, with the big errors being in shades of blue. Skin tones are very well reproduced, which is something I’ve seen other devices struggling with in recent reviews.

Overall, the Lumia 640’s display is very good, and I would go as far as to say that it’s one of the best displays on a phone at this price point. It performs well in every category, from brightness, to contrast, to color accuracy, and the resolution is high enough to keep everything looking fairly sharp. I think Lumia 640 users will be very happy with the display on their phone.

System Performance Camera Architecture and UX
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  • Cryio - Tuesday, June 9, 2015 - link

    Lumia 520 has a dual core Krait CPU. Much faster than a dual core SD200. Reply
  • testbug00 - Tuesday, June 9, 2015 - link

    yes, I forgot. My bad. Herp derp. Qualcomm's naming scheme is cr*p still. Reply
  • MrSpadge - Tuesday, June 9, 2015 - link

    The Krait is clocked at 1.0 GHz in the Lumia 520. It's pretty close in performance per clock to an A9, which itself is not much faster per clock than an A7. Overall 4 x A7 at 1.2 GHz is about as fast as 2 x Krait at 1.0 GHz for single threaded loads. Reply
  • StevoLincolnite - Wednesday, June 10, 2015 - link

    Got a Lumia 535 as secondary windows phone device (Got a Lumia 920 as my daily driver still - Dual-Core 1.5ghz Snapdragon S4, Adreno 225) which has a Quad-Core Snapdragon 200 and Adreno 302.

    Both run without stutter and run smoothly in everything... With one exception, Internet Explorer, but even that's perfectly passable.

    Even played with 520's, 525's, 610, 620, 630 phones and they have been fine... I would assume something must have been up with the reviewers device, one thing Windows Phone has always never had a problem with is fluidity.

    Microsoft needs a new high-end device, I need an excuse to upgrade my Lumia 920 which is years old now, the 930 simply wasn't it.
    Reply
  • Daniel Egger - Tuesday, June 9, 2015 - link

    I disagree. Performance is terrific on those devices, actually much better better than the much cited Moto E 2nd gen which requires a lot of tinkering to actually provide a comparable fluidity. Reply
  • tipoo - Wednesday, June 10, 2015 - link

    What tinkering did your Moto E need? My Moto G runs just fine. Reply
  • SirPerro - Monday, June 15, 2015 - link

    That's bullshitty at its best. Which "tinkering" is it required to make the Moto E fluid? (Answer: None) Reply
  • Frenetic Pony - Tuesday, June 9, 2015 - link

    You're thinking it's the same as Android, Windows Phone (or Windows for phones, or wtf ever they call it) has generally been a lot smoother on lower spec phones than Android. Reply
  • Frenetic Pony - Tuesday, June 9, 2015 - link

    You're thinking it's the same as Android, Windows Phone (or Windows for phones, or wtf ever they call it) has generally been a lot smoother on lower spec phones than Android. Reply
  • haukionkannel - Wednesday, June 10, 2015 - link

    Well I have Lumia 625 (slower phone than this) and it is very fine in navigation! So no problem in there! It is not good for gaming, but every other task is just fine with this phone. Reply

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