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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  • BabelHuber - Friday, June 12, 2015 - link

    It depends on the software you use - nobody forces you to use the software the phone shipped with. For teh SGS4, I prefer AOSP-based ROMs or GPE-versions.
  • Margalus - Thursday, June 11, 2015 - link

    oh, and I am not ms propaganda. The phone wasn't bloated. Brand new out of the store with no apps it wouldn't last more than a day. The person at the store even told me that I would have to charge it every day. I also bought a replacement battery to use since it died so fast, that replacement battery works exactly the same as the stock battery. Barely 24 hours.
  • BabelHuber - Friday, June 12, 2015 - link

    You claimed your WP-phone lasts 5-8 times longer than your Android phone, didn't you? Perhaps this was slightly exagerated?

    But be it as it may, when I have battery problems I actually tend to install a tool to analyze things. Then I can deinstall or freeze the app which causes the problem or block its wakelocks. Problem solved.

    Some other people may prefer to whine because of their low battery runtime instead, to each its own.
  • leexgx - Friday, June 12, 2015 - link

    most avg for battery life is a Nearly a working day for most smartphones (8-12 hours)

    (if you turn off mobile data 3 days is easy maybe even 5 if you can get your phone to use 2G only) and Most people do not AOSP ROM there phone
  • we - Thursday, June 11, 2015 - link

    Two things I cannot confirm (using a fully updated HTC 8X). 1. Action center always flows smoothly. Never had any stuttering or freezing. 2. Generally Scrolling speed is proportional to swipe speed. I can scroll from top to bottom of the "Windows Phone" page of this review within 5 seconds if I swipe quickly, or 15 seconds if I swipe slowly. Top scrolling speed could be faster though.
  • Zizy - Thursday, June 11, 2015 - link

    Currently using lowly HTC 8s which was the worst WP8 phone till 435, no issues with action center - no delay or freeze. It has somewhat strange/unexpected opening, because it can be fully opened or just enough to play with those 4 buttons and or go in settings. I never had enough unattended notifications to be able to test scrolling there.

    Camera - This isn't a proper camera with viewfinder or at least tiltable display. Ever tried underexposing something under bright sun? You wouldn't be able to see anything on the screen. But it would be good to have some notification to tell how many stops below the preview the image is going to end. If you are serious enough about manual stuff this should be enough to know how will the image turn out :)

    As for idle battery drain - try activating battery saver and see the power draw then, plus check which apps drain the battery. If it is the same, probably screen, something failed to close / is intentionally running in the background or some other hardware/software bug. Shouldn't happen but does. Manually closing apps usually resolves the problem.
    If battery saver does help, play with sync settings for mail and similar. For me, syncing mails as they arrive instead of manually every now and then drops battery life from 3-4 days to 1-2 (light use - no demanding games). If you get tons of mail it will be even worse.
  • Harry_Wild - Monday, June 15, 2015 - link

    I just purchased an international version of the 735 and I love it for $300. It is unlocked. I purchased a cyan battery cover too. It feels like a iPhone 6 with a case on it! Same thinnest! The 400 is slow in some operations; but overall it pretty good overall. I switch to the iPhone 6 and back from day to day since they use the same nano SIMs card inside. My iPhone cost $900 so performance is quite a bit faster on everything. But still I like the change of environments. The WP does not have all the apps that I use so most case I pin the webpage and create an icon tile as a substitute. It works for a lot of Apple apps except for Apple Pay and Starbuck's Pay.
  • SirPerro - Monday, June 15, 2015 - link

    I'm just amazed at how people can deny the reality in front of them.

    This phone has a better camera/screen than a Moto E and it is MUCH worse in every other regard. The app selection and quality of the apps is orders of magnitude worse. The web browsing experience is laughable. The overal OS experience and fluidity is worse, no matter how much iOS/WP fanboys keep repeting stupidities about android performance.

    The only reason Windows Phone is alive is because Microsoft has a HUGE pile of cash they can burn if they want to stay in the game, and I seriously pity everybody who puts they hard earned money in such a shitty and undeveloped ecosystem.

    Even with the screen and camera, I find no single person in the planet to which I'd reccomend this phone over a Moto E. And while I'm probably much less polite, the bottom line of the review is Brandon & Anandtech agree with that.
  • Zizy - Tuesday, June 16, 2015 - link

    Quick check whether you need Android/iOS ecosystem:
    Need an app not on WP? Don't get WP.
    Really want anything social (games or apps)? Don't get WP.
    Completely tied to Google/Apple? Don't get WP. Note that plenty think they are tied to google but only really need their search, mail and youtube and could easily ditch the rest.

    Not found yourself up there? You will bitch about WP... but you will bitch about Android and iOS as well :)

    ---

    Want better hardware? Go with Lumia. Software? Moto E.
    Would I buy Lumia 640 though? Heck no. I have a WP dev phone already, don't need another. As a primary phone, this one still has too poor camera for my wishes. Lumia 830 is much more tempting, but costs quite a bit more.
  • BaronMatrix - Monday, June 15, 2015 - link

    MS is so pissing me off... First they destroy how I use my desktop, now since they bought Nokia NOT ONE NEW PHONE HAS COME OUT...

    You can't get the 640 anywhere... T-Mobile has it coming soon for MONTHS... And no 640XL even mentioned... Even the MS Store doesn't mention the 640...

    I'm through with Windows Phone... I'll keep one for DEV, but I'm getting an Android phone... I'd rather be able to get all the cool apps that don't come on Windows Phone...

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