As we briefly discussed in our look at the specifications, the Galaxy S6 line introduces a newer generation of AMOLED displays, which is said to increase maximum luminance to 600 nits. Samsung claims that this was achieved with the use of new materials, which is likely necessary in order to sustain power efficiency improvements. It doesn't seem that AMOLED is uniquely suited to high resolution, but rather that Samsung Display Corp. is managing to dramatically improve how they make AMOLED displays with every year that offset power consumption increases from higher resolution displays.

To find out how Samsung did, we use SpectraCal's CalMAN 5 Ultimate, in addition to X-Rite's i1Pro2 Basic to characterize displays as accurately as possible.

Display - Max Brightness

From the results Samsung's claims of a 600 nit display are valid in this case, which is a 100% APL white display. It's important to note that achieving this requires the use of auto-brightness, and that manual brightness is limited to a much lower brightness to reduce power usage, here the S6 sees similar maximum brightness as the S5. The S6 edge disappointingly only achieves 272 nits in this mode, a rather low value. I saw color balance shift dramatically in auto-boost mode, which suggests that this operating mode is likely less efficient than manual brightness. As an explanation, we've seen that colors are controlled in AMOLED by voltage while brightness is controlled by PWM (pulse width modulation). As with most recent AMOLED displays, there's no DC bias to the pixels so the contrast really is infinite instead of just a very large number when displaying black.

Galaxy S6

Galaxy S6 edge

Display - White Point

Display - Grayscale Accuracy

Moving on to grayscale, we can see that Samsung has done a pretty good job of controlling the white point and gamma across the saturation sweep, even if green is slightly dominant in both displays. We can also see that there is variation across displays as the S6 edge is closer to neutral while the S6 sample tends a bit warmer.

Galaxy S6

Galaxy S6 Edge

Display - Saturation Accuracy

In the saturation sweep, both displays do an incredible job. I really don't have anything else to say here, because there's really no way to improve on the level of calibration Samsung has done on this display. Unless Samsung calibrates every single display in production, which is wildly impractical and effectively impossible to do, this is as good as it gets for a mass-produced device. Improving past this point will also be incredibly difficult to perceive, which means there's no real reason to go any further.

Galaxy S6

Galaxy S6 edge

Display - GMB Accuracy

In the Gretag MacBeth ColorChecker, we can get an idea for overall color accuracy, which paints a picture similar to the saturation test. The only real problem I've noticed with these displays are the viewing angles, which can produce color shifting when the display is tilted. This is a bit of an issue on the edge variant as I can see that the edges of the display appear somewhat green when viewed head on, but otherwise there are no real issues to be seen here.

Overall, from a color standpoint it’s looking like Samsung has made one of the best displays available on the market today. Color accuracy is at the point where it’s pretty safe to say that the calibration doesn’t have clear color errors, and the peak brightness of the display is incredibly high. The 1440p resolution helps to compensate for the PenTile subpixel layout so in practice it’s effectively impossible to make out any pixels or the subpixel pattern. The contrast remains infinite as with most modern AMOLED displays, and overall it’s really hard to find any issue with the Galaxy S6’s display at first.

However while the S6 edge seems to be without any issues, the S6 does have some odd display issues that can be seen in direct sunlight as seen in the photo above. To be clear about this the photo above is a simple white screen, which should make the image completely homogeneous but instead there are two visible vertical lines and another jagged horizontal line that appear across the display. Inspection under a light microscope doesn’t really reveal what’s causing this, but the defect is quite visible in practice as seen in the photo above. I suspect that defects are rare, and in any condition other than direct sunlight I can’t see this visual problem.

While trying to see what this kind of defect looked like under a microscope, I also went ahead and took some photos of the subpixel pattern. As far as I can tell, it looks like the green subpixels have a bit more variance than what we’re used to as they tend towards oblong shapes rather than circles, which is likely due to the much tighter pixel density. It seems that this variance may cause some color shifting in certain units, which seems to remain a potential problem with Samsung's AMOLED displays. The pixel fill factor still remains surprisingly low when compared to LCDs, which usually have much higher active area. Due to the subpixel arrangement and some other differences in the display design, color shifting also remains higher than one would expect from LCD displays that are found in phones like the iPhone 6.

The final test that I managed to run on the Galaxy S6 is the brightness vs APL test, which shows the advantage of AMOLED’s emissive nature as it can dynamically increase brightness if the entire display isn’t showing a white screen. As a result, this means that in low APL scenarios like dark movie scenes and app themes it’s possible to see a maximum brightness closer to 700 nits or higher. However, in practice the display’s practical brightness is closer to 600 nits.

Overall, the display is still one of the best on the market, but I would be a bit concerned about fill factor for VR applications as that was a problem on the Note 4. Issues like purple smearing have been resolved, but there are still some problems with the display such as color shifting with changes to viewing angles and some variability in display quality from unit to unit. With this generation I suspect Samsung is either meeting or exceeding the best LCDs in quality, and with the next generation of AMOLED it’s likely that high end smartphones will have to migrate to AMOLED to remain competitive.

Battery Life and Charge Time System Performance


View All Comments

  • hlovatt - Saturday, April 18, 2015 - link

    Firstly, great review. Love all the detail and care taken in obtaining the results.

    I am glad to see the changes Samsung have made. The S4 and S5 were really oh hum phones, not deserving the flagship monicker. This time they have produced something that will challenge Apple, HTC, etc.
  • melgross - Saturday, April 18, 2015 - link

    $45 isn't all that much. You would save $15 by doing it yourself. So you will need tools to pry the case apart after you've softened the glue using a hairdryer. How do you intend to put it back together? Reply
  • xenol - Friday, April 17, 2015 - link

    I just don't find myself needing an SD card slot, if only because I don't really fill my phone up anyway. I'm really wondering what other people fill their phones up with in order to need an SD card slot. I was under the impression that music is just lifted off internet radios and videos from YouTube or some other service (and if they want to watch a lengthy movie, they'll add it in when they want to).

    I don't know, maybe I'm just the kind of person who doesn't mind managing data and don't have a lot to begin with on the phone.
  • esterhasz - Friday, April 17, 2015 - link

    I have a lot of music on my phone and videos for the kid. Having to pay such a premium for a 64gb version is hard to swallow when sd cards are really cheap. Reply
  • SkyBill40 - Friday, April 17, 2015 - link

    Agreed. Like you, I've got a lot of music on my phone and it's all on an SD card.

    I'm upgrade eligible at any time from my Note 3 but am seeing how long I can or am willing to hold off for the next round of releases. If the Note 5 isn't a substantial improvement over the 3/4 or whatever, I'll likely jump to another vendor that has the right mix of things I'm after. It'll either be another Android phone or *maybe* Windows. No way in hell will I ever jump to Apple.
  • RiotSloth - Thursday, May 14, 2015 - link

    In the UK it's about the price of a point of beer a month to go from 32 to 64 gig. Well worth it for me. Reply
  • JeffFlanagan - Friday, April 17, 2015 - link

    I used to need 128GB to load TV and movies onto my phone, but yes, now I can stream video from home via Plex, in addition to watching NetFlix, so the internal 64GB is plenty. There will be a 128GB version for people who need more space. We no longer have to take a performance hit to get 128GB via SD card. Reply
  • will54 - Monday, April 20, 2015 - link

    I love my lossless Flac and WMA audio which takes up about 5-7X more space than an mp3 so I need my 32+128 GB's. The quality is worth the extra space imo. Reply
  • RiotSloth - Thursday, May 14, 2015 - link

    Have you ever tried a double blind test between high and regular versions on your phone? Genuine question, I'm curious. Reply
  • andyasia - Friday, April 17, 2015 - link

    I could Bluetooth my data to my laptop as backup, or swap data time to time as I like, so no problem there. ☺ Reply

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