Display

As always, the display of any mobile device is a critical part of the overall user experience. A poor display in any way is often going to sour the entire experience.

On a personal note, there are a number of mobile devices that I’ve used over the course of the previous year that frankly just weren’t good enough for me to use as a daily driver because the display just wasn’t good enough. My laptop is quite closely calibrated to sRGB and it’s used to edit all of my device photos, so I’ve really come to appreciate a device that has sufficiently accurate color that I can actually use a phone or tablet as a reference monitor of sorts to verify that images look the way I want them to.

In order to test this critical portion of the user experience, we turn to our standard test suite which uses SpectraCal’s CalMAN 5, a custom workflow for testing basic metrics like brightness, contrast, and calibration accuracy, and X-Rite’s i1Pro2 and i1DisplayPro.

Starting off with a microscope's view of the Galaxy S7's display, it looks like Samsung has elected to keep most aspects of the display constant when comparing the Galaxy S6 and S7. At a high level, the display is the same 5.1” display size that we’ve seen for a few generations now, and the 1440p resolution is shared with previous devices. Samsung continues to use their diamond PenTile layout, but it’s hard for me to say whether there’s been an adjustment to the size of the emitters as the microscope I have on hand isn’t quite sufficient for making such measurements. It’s likely that under the hood there are changes to the display driver IC in order to enable features like Always-On Display, but as we’ll soon see it’s rather unlikely that there are any generational changes in things like the emitter material or TFT backplane.

Display - Max Brightness

One of our first tests here is a pretty standard test of maximum luminance. Here, we see that the Galaxy S7 and S7 edge both are in the same general ballpark as the Galaxy Note5, which suggests that both devices are likely to be in the same generation of AMOLED panel. This brightness was achieved by using the auto-brightness mode, so it’s important to note that the max luminance in manual mode will be much lower. Of course, this brightness figure was determined with a full white display so reducing the APL will result in a higher maximum luminance as the power budget can we spent on fewer pixels which means that a higher duty cycle can be achieved in each pixel.


Galaxy S7


Galaxy S7 edge

Display - Grayscale Accuracy

Display - White Point

The next part of our testing is grayscale. As always, we target the industry standard of a 2.2 power gamma with 6504k white point. Relative to the Galaxy S6 and Note5, we see a pretty significant improvement in white point accuracy as it’s pretty much consistently quite close to a neutral white rather than a warmer color balance. Unfortunately though, in both review units I received the display has a noticeable green tint for many shades of grey, which seems to be somewhat of a perpetual problem with Samsung AMOLED displays. This really does affect quite a bit of the UI, as Material Design greys have this noticeable green tint to them that really makes things look off.

The same issue seems to not be present on the Galaxy S7 edge, which leads to a significant improvement overall in calibration quality for this portion of the testing, but both devices have a noticeably lower gamma than expected, which does have some effect on accuracy but for the most part can help to serve as a compensation mechanism for reflectance when dealing with ambient light. It’s likely that the green tint issue may only appear on a device to device basis, but to see that such issues haven’t been resolved for years is somewhat concerning given that phones costing hundreds of dollars less don’t seem to have the same problems.


Galaxy S7


Galaxy S7 edge

Display - Saturation Accuracy

The next portion of our testing is the standard saturation sweep test. Here, the Galaxy S7 and S7 edge are basically perfect. It’s great to see that Samsung continues to provide their Basic color mode with a real focus on providing accurate color calibration for those that care about these things, and the user experience with getting to the right color calibration is pretty much as painless as it can be compared to some other devices where things like saturation curves, white balance, and other parts of a display calibration can only be adjusted using unitless sliders that basically require a spectrophotometer to actually use.


Galaxy S7


Galaxy S7 edge

Display - GMB Accuracy

In our Gretag MacBeth ColorChecker test, we see that there are some issues with grayscale accuracy, but overall color accuracy remains quite good. In terms of overall display quality, I don’t really think there’s any meaningful improvement over the Galaxy S6, but that’s mostly because the Galaxy S6 set a ridiculously high bar for display quality.

However, I don’t believe that Samsung has run out of things to improve for future AMOLD displays. In addition to the grayscale problems mentioned earlier, Samsung clearly has not resolved issues with color shifting that occurs with viewing angle changes. LCDs definitely have more luminance degradation as you move away from the normal of the display plane, but at almost every angle change I can see whites get noticeably colder and interference patterns, in addition to a general color shift that is noticeably more than most LCDs used in high end smartphones and tablets. It’s obvious that this is a hard problem to solve due to uneven subpixel aging, but for things like tablets, laptops, and desktops color shifting is going to be a much more significant issue.

GPU Performance Software UX
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  • fanofanand - Tuesday, March 8, 2016 - link

    I have to agree with this assessment, I won't buy another phone without an IR blaster. I have 3 kids, and the remotes are ALWAYS missing. Reply
  • iheresss - Tuesday, March 8, 2016 - link

    There is no such thing as 'shot noise'. Every digital noise is just lack of light to hit sensor. By having larger pixel size means larger area for light to hit photo sensor hence reduce the 'sensor noise'. Reply
  • ah06 - Tuesday, March 8, 2016 - link

    But unless the total size of the sensor is increased, isn't increasing the pixel size making only a minor difference?

    A 1/2.5" sensor is only going to collect X amount of light whether it collects it over 16 million 1.1 um pixels or 12 million 1.4 um pixels.

    The only (very slight) gain over the higher pixel count is the loss at pixel boundaries due to pixel pitch.

    Am I wrong?
    Reply
  • frostyfiredude - Tuesday, March 8, 2016 - link

    Because the sensing area is larger per pixel, the number of photons incident in each pixel will increase with it. Those incident photons are what give the picture data. So weird quantum effects that somewhat simulate adding or removing photons have less significance when there are more photons to begin with.
    More specifically at 1.1um vs 1.4um, 1.1um being quite comparable to the wavelength of visible light is causing some extra anomalous effects too.
    Reply
  • ah06 - Wednesday, March 9, 2016 - link

    Yea I knew 1.1 um was the bare minimum due to quantam effects. But say going from 1.4 um to 2.0 um, would that make much of a difference?

    After all the total amount of light collected by the sensor would be roughly same right?
    A flower can be composed of 10 million pixels of size X or 5 million pixels of size 2X, the total area of the flow will still have collected the same light?

    Where am I going wrong with this :P?
    Reply
  • arayoflight - Tuesday, March 8, 2016 - link

    Actually no. The sensor on s7 is a 4:3 1/2.5" sensor while the one in s6 us a 16:9 1/2.6" one.

    What it means is that it collects about 21.49% more licht than the one on s6.
    Reply
  • ah06 - Wednesday, March 9, 2016 - link

    You're right about the aspect ratio difference, hope more reviewers cover that there is no "Real" loss of resolution .

    However, does increasing pixel size really affect total light collected by sensor?
    Reply
  • jospoortvliet - Friday, March 11, 2016 - link

    I don't think it does, but it decreases noise caused by chance: with smaller pixels you have noise in low light situations in part simply due to the chance of one pixel catching randomly a bit more licht fotons than correctly represented the scene, and another less. With bigger pixels you smooth that out a bit and thus less random noise. It is only ONE source of noise, but it helps.

    Just imagine you take a pic of the same scene with two sensors, one so small it catches 5 photons average per pixel cell, the other one is twice as big and catches, on average, 10. A random one photon difference in a given pixel cell gives 20% brighter or darker pixels on the small, 5 photon-catching sensor and only 10% on the bigger one.

    Again, it is only one source of random noise, but a pretty fundamental one you can hardly calculate your way out off.
    Reply
  • adamto - Tuesday, March 8, 2016 - link

    @Joshua Ho. Do you mind if I ask favor? Does S7 support AC tethering? Do you now any other Android phone with AC tethering? I am not talking about connecting S7 phone to a 5Ghz wifi such as home internet. These days most phone can connect to 5GHz wifi anyway. What I am asking is. If S7 itself can become a 5Ghz WiFi hotspot. This is can be very useful feature for me for transferring files between connected device to S7 tethering. I appreciate if you share with us a screenshot of network connection speed at PC to the S7 tethering at second part of review. Thanks! Reply
  • nerd1 - Tuesday, March 8, 2016 - link

    Web browsing bench using chrome AGAIN????? How many times have anandtech been criticized for this? Reply

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