Firmly seated as a goliath in the multimedia industry, the Sony Corporation produces electronics that are well-respected in many different tiers and categories. From consumer audio equipment to prosumer cameras and professional reference monitors, one would think that Sony can make a beast of a handset that combines the company’s many fields of expertise.
Unfortunately, this hasn’t been the case for their past couple of phones. Although Sony has found success in its individual product divisions, there seems to be a lack of coordination when putting it all together into a phone. Last year, I reviewed the display in Sony’s first Xperia 1 device, a phone that Sony had catered towards content creators. While the display itself was decent enough to look at for most consumers, I was disappointed in the direction that Sony had taken in its calibration. It’s unreasonable for me to expect anything at the same level as Sony’s Master Monitors (which they claim inspiration from), but I did expect at least some resemblance to their high-end televisions. And I was let down after seeing that there just wasn’t.
For those that haven’t read the review, the Sony Xperia 1’s display lacked a true sRGB-conforming color profile; the provided Creator mode was not calibrated to a D65 white point, and it (inconsistently) targeted 2.4 gamma power for all content. While this does not entail a badly-calibrated display (phone displays should not target a 2.4 gamma power to begin with), the phone cannot render content within the same color standard that the Internet has agreed to use, so the device cannot be benchmarked at the same standard as other devices. Sony has noticed this issue, and I’m glad to see that it managed to address this in its second-generation Xperia 1 device, the Sony Xperia 1 II (“Mark II”).
Sony Xperia 1 II Display Review Highlights
Pros
- Sharpest display with no hint of color fringing
- Great color accuracy in “Creator mode” with D65 preset
- Good HDR playback
Cons
- Peak brightness falls behind other phones at the same price point
- Flat picture contrast in Creator mode
- No high refresh rate panel
- Color consistency falls apart near minimum brightness
All the pixels
The Sony Xperia 1 II continues to back Sony’s choice of putting an ultra-wide 4K display in their flagship smartphone. At a comfortable viewing distance and with the display size, the difference in viewing 4K content on the 4K resolution panel is subtle compared to viewing that same content on a 1440p panel. For content and apps that aren’t native 4K, the phone renders at 1440p to preserve some processing power. Due to the diminishing returns of increased pixel density and the higher power draw of 4K, this isn’t a decision that I would personally ever make if I were designing a smartphone display today. However, I do understand that the Sony Xperia 1 II is a niche product for those who may spend much of their time monitoring 4K content.
Motion blur reduction
With the Xperia 1 II, Sony added a new display feature called “Motion blur reduction” which helps reduce ghosting in fast-moving content. Most forms of effective motion blur reduction are achieved by inserting a black image in-between frames or by strobing the backlight of the display. However, that doesn’t seem to be how it works on the Sony Xperia 1 II. Sony told Engadget Japan that the Xperia 1 II “will increase the voltage in time with the activation of the OLED pixels when displaying an image,” and that “even if you send the instruction to activate a pixel it takes some time to switch from black to white, which can result in the pixel looking grey.” YouTuber 忍の動画 uploaded a handy video that compares the Sony Xperia 1 II’s display with the motion blur reduction feature on and off:
Motion blur comparison / Credit: 忍の動画
While we haven’t had official confirmation, it seems that Sony’s feature aims to improve pixel transition time instead of improving image persistence. The problem with this angle is that the transition time (G2G) for lit pixels on an OLED is already nearly instantaneous, and that persistence (MPRT) is the main cause of motion blur, which Sony’s feature does not improve. However, the transition time for black or near-black colors onto similar tones on an OLED is actually quite slow. This can sometimes be seen as a trailing blue or purple trail behind dark moving elements on the display, and it has been a consequence of OLED displays since its inception. I was eager to see if Sony’s feature improved the trailing at all, but from my testing, it made no difference. I’ve found Sony’s motion blur reduction to be uninspiring, ineffective, and not really worth much further investigation. Implementing a motion blur reduction feature that is actually effective would cripple the display brightness, and the Sony Xperia 1 II does not have much headroom available. In any case, a higher refresh rate panel would be a better installment every time.
Display panel
The display hardware in the Sony Xperia 1 II seems to be an earlier-generation Samsung panel. It is still an 8-bit panel that has the same output capabilities as last year’s. The typical peak brightness of the panel is about 550-650 nits depending on APL, and its color gamut extends just past DCI-P3. This was considered high-end from Samsung’s panels in 2017 and 2018, but they have now surpassed that—around 750-900 nits is what you can expect from today’s panels. I imagine that Sony had decided to hold back on a newer panel perhaps because Samsung doesn’t make any with a 4K resolution yet.
The screen doesn’t seem as plastered to the top of the glass as its competitors. While this quality doesn’t appear in measurements, it is something that can be subtlety noticed, especially at an angle. The angular color shift of the panel is also not as low as our current flagship OLEDs, although it is not offensive by any means.
Color profiles
Gamut for Creator+Standard
Sony keeps it simple with just two color profiles. The default “Standard” profile saturates colors slightly higher than the sRGB standard and shifts the white point considerably cold. The “Creator mode” profile is the display’s color-accurate profile, intended for content creators to view their work faithfully. Both profiles seem to target the same 2.20 gamma power, but as evaluated later on, the actual contrast between the two profiles is different.
The “Standard” profile sports a cold 7800 K white point (likely targeting D75) whose color primaries are in-between those of the sRGB and P3 color standards. Compared to sRGB, the Standard profile is up to 21% larger. Its reds are up to 13% larger, tinting noticeably towards orange. Greens are up to 14% larger, maintaining the same hue. Blues are about 9% larger, tinting slightly towards magenta. As mentioned earlier, the tone mapping of the profile is similar to that of Creator mode’s, which targets the standard gamma power of 2.20.
The “Creator mode”, meant to be the “accurate” profile, initially misses the mark at its white point. By default, the profile has a white point of about 7100 K, which is significantly colder than the standard 6504 K. At this white point, the profile’s color accuracy is unremarkable; all color tones are shifted blue, however, color mixtures appear finely adapted to the given white point. For the most accurate picture, the white balance of the profile must be set to D65. While this does improve color accuracy, the panel and display profile should really have been calibrated to D65 at the factory for maximum precision.
Both profiles allow the user to adjust the white point and apply color correction (PCC) to the individual RGB color channels. Sony also provides the white point selection of canonical illuminants, namely D50, D55, D65, D75, and D93. This is a great addition that other OEMs should provide as an option to allow content creators to see their work in the other standard illuminants.
Methodology for gathering data
To obtain quantitative color data from the display of the Sony Xperia 1 II, I stage device-specific input test patterns to the handset and measure the display’s resulting emission using an X-Rite i1Display Pro metered by an X-Rite i1Pro 2 spectrophotometer in its high-resolution 3.3nm mode. The test patterns and device settings I use are corrected for various display characteristics and potential software implementations that may alter our desired measurements. My measurements are typically done with display-related options disabled unless mentioned otherwise.
I use constant power patterns (sometimes called equal energy patterns), correlating to an average pixel level of about 42%, to measure the transfer function and grayscale precision. It’s important to measure emissive displays not just with constant average pixel level, but also with constant power patterns since their output is dependent on the average display luminance. Additionally, a constant average pixel level does not inherently mean constant power; the patterns I use satisfy both. I use a higher average pixel level closer to 50% to capture a midpoint between both the lower pixel levels and the many apps and webpages with white backgrounds that are higher in pixel level.
I use the latest color difference metric ΔETP (ITU-R BT.2124), which is an overall better measure for color differences than ΔE00 that is used in my earlier reviews and is still currently being used in many other sites’ display reviews. Those that are still using ΔE00 for color error reporting are encouraged to use ΔEITP.
ΔEITP normally considers luminance (intensity) error in its computation, since luminance is a necessary component to completely describe color. However, since the human visual system interprets chromaticity and luminance separately, I hold our test patterns at a constant luminance and do not include the luminance (I/intensity) error in our ΔEITP values. Furthermore, it is helpful to separate the two errors when assessing a display’s performance because, just like with our visual system, they pertain to different issues with the display. This way, we can more thoroughly analyze and understand the performance of a display.
Our color targets are based on the ITP color space, which is more perceptually-uniform than the CIE 1976 UCS with much better hue-linearity. Our targets are spaced out roughly even throughout the ITP color space at a reference 100 cd/m2 white level, and colors at 100%, 75%, 50%, and 25% saturation. Colors are measured at 73% stimulus, which corresponds to about 50% magnitude in luminance assuming a gamma power of 2.20.
Contrast, grayscale, and color accuracy are tested throughout the brightness range of the Sony Xperia 1 II’s display. The brightness increments are spaced evenly between the maximum and minimum display brightness in PQ-space. Charts and graphs are also plotted in PQ-space (if applicable) for proper representation of the actual perception of brightness.
ΔETP values are roughly 3× the magnitude of ΔE00 values for the same color. The metric assumes the most critically-adapted viewing condition for the observer: A measured ΔETP color difference value of 1.0 denotes a just-noticeable-difference for the color, while a value less than 1.0 signifies that the measured color is indistinguishable from perfect. For our reviews, a ΔETP value of less than 3.0 is an acceptable level of accuracy for a reference display (suggested from ITU-R BT.2124 Annex 4.2), and a ΔETP value greater than 8.0 is noticeable at a glance (tested empirically, and the value [8.0] also nicely lines up with a roughly 10% change in magnitude for luminance, which is generally the percentage needed to notice a difference in brightness at a glance).
HDR test patterns are tested against ITU-R BT.2100 using the Perceptual Quantizer (ST 2084). HDR sRGB and P3 patterns are spaced out evenly with sRGB/P3 primaries, an HDR reference level white of 203 cd/m2 (ITU-R BT.2408), and a PQ signal level of 58% for all its patterns. All HDR patterns are tested at an HDR-average 20% APL with constant power test patterns.
Brightness
The peak brightness of the Sony Xperia 1 II is mostly unchanged from, if not slightly dimmer than, the original Xperia 1. The reason for the reduction is that the Xperia 1 II now equalizes the display brightness with the on-screen APL, resulting in nearly no perceptual change in display white level when content changes. This helps improve the accuracy of the contrast in content but sacrifices brightness in some conditions. As usual with Android phones, the actual peak brightness of the display is only accessible in auto-brightness when under bright light. In manual mode, the Sony Xperia 1 II is limited to about 350 nits fullscreen (100% APL) brightness.
The median-case 50% APL brightness under sunlight averages about 600 nits, compared to 630 on the original Xperia 1. For HDR content, the Xperia 1 II’s display will slightly boost the brightness for small regions of white, peaking at 710 nits for 20% APL. These values are typical of Samsung’s 2017-2018 generation panels, and while they’re still decent, they’re not competitive with devices that boast 800-nit fullscreen brightness and true 1,000-nit HDR highlights, which we should expect from a phone at this price.
One other annoyance I found with the Xperia 1 II is that Sony still uses linear brightness value mappings, causing notable jumps when adjusting the brightness (manual or auto-brightness) at lower levels. It’s not too important, but it shows some lack of polish.
Contrast and Tone Mapping
The biggest difference in the display of the Xperia 1 II is in its contrast. The newer Sony Xperia 1 II now targets the standard 2.2 gamma power by default, which is a welcome change. The original Xperia 1 targetted a 2.4 gamma power, which is commonly used in darkroom TV calibrations. This can be useful for actual filmmakers (or those filling a niche), but it is not fit for other conditions and most content that is viewed on a smartphone. In normal conditions, the higher gamma yielded steeper contrast and darker colors. The obvious option here is to give the user a choice, which Sony does not do for either generation of devices. However, when watching videos in a media player app, the display now tone maps to a gamma power of 2.4. It would still be better if options were provided, but Sony’s solution is a solid middle ground that caught me by surprise.
Regarding the performance of tone reproduction, the actual contrast in the Sony Xperia 1 II display is very problematic. Assessing it against constant APL and constant power patterns, I measured Creator mode to have significantly lifted shadows, especially at higher brightness. Black crush isn’t a problem thanks to this, but it causes content to appear washed out. The most fitting gamma power that best describes the Xperia 1 II’s transfer function would be close to 1.90, which is much lower than the standard of 2.20. On the bright side, the lifted shadows can improve the legibility of content under brighter lighting, but in typical usage, it just results in a flatter image. If the lightened shadows are indeed intentional for sunlight legibility, then the tone mapping should be a function of ambient lighting (I measure displays in a darkroom), not display brightness. The Xperia 1 II’s display contrast is a complete 180 from the first-generation Xperia 1 which actually had too much contrast for generic content. Unfortunately, I didn’t get around to testing the accuracy of the display’s 2.40 gamma power within video content.
On the other hand, Standard mode appears to have much more accurate and better-controlled picture contrast. This is conflicting in that Standard mode is not meant to be an accurate color profile, yet it performs much better in the fundamental reproduction of the content structure. There is still a slight lift in at lower brightness and a slight crush at around 80% PQ brightness, but because of its relative tonal accuracy, I would recommend using the Standard profile over Creator mode for tone mapping shadows, while monitoring color saturation with Creator mode.
White Balance and Grayscale Precision
The corresponding average white points for the Standard profile and Creator mode are 7800 K and 7100 K, respectively. Both of these are significantly colder than the D65 standard of 6504 K. Given that Creator mode is supposed to follow color standards for content creators, it makes no sense to calibrate the white point as cold as Sony did. However, the white point is adjustable, and selecting the D65 preset shifts the white point closer to about 6600 K with less overall color error.
When displaying the same color at varying system brightnesses, our Sony Xperia 1 II shows mediocre color drift that is higher than what a flagship display should exhibit. Both profiles have a color difference standard deviation greater than the noticeable threshold (ΔETP > 3.0), meaning that many colors lie outside the average measured color temperature. Darker color tones at lower brightness steer substantially green, causing shadows and dark interface elements to appear flat and skewed. Manufacturing tolerance does play a large role in the precision of darker colors, and other Sony Xperia 1 II display units may appear more consistent (or worse). However, the moderate spread among even the lighter colors suggests that this can be expected behavior from Sony’s quality control.
Color Accuracy
sRGB color accuracy for Creator (D65)
Since a D65 white point is a necessary basis for our standard color spaces, the colder calibration of Creator mode’s default white point is not initially accurate. With the profile’s default white point, there is an average color error ΔETP of 3.9, which is above our noticeable threshold of ΔETP > 3.0. Selecting the D65 white balance preset does significantly improve measurements, and it results in remarkable color calibration in most conditions with an average color error ΔETP of 2.5. However, I found there to be an undersaturation of reds around the minimum brightness, which washes out the appearance of the display during nighttime viewing. My prior grayscale measurements have also shown color bias towards green for the panel’s darker shades, and we can also see the white point shift towards green for my lower brightness measurements.
HDR Playback
As the number of HDR10 and Dolby Vision titles steadily increase on our favorite streaming service platforms, we can more often utilize the full potential of our high-end display panels. Playing back HDR content is currently the best demonstration of a display’s output capabilities, and it can easily be the most impressive display experience for the consumer. The display on the Sony Xperia 1 II has an aspect ratio that conforms to many cinema formats, creating a bezel-less movie watching experience by removing the need for letterboxing. It can also record videos in HDR format (albeit in HLG), which while we are a long ways away from adopting and normalizing, is nonetheless impressive and gives us immediate access to content that showcases the display’s performance.
The Sony Xperia 1 II reproduces the standard HDR ST.2084 curve nice and closely, except for a slight bump up in near-black colors. The Xperia 1 II’s peak typical brightness in HDR content gets up to about 710 nits, which doesn’t quite hit the 1000-nit standard but is enough to deliver convincingly bright highlights in a dark viewing environment. Additionally, unlike other Android phones that I’ve tested, Sony’s HDR color management system actually seems to apply tone mapping towards its peak brightness up to 75% PQ signal level for 1ooo-nit HDR content; other Android phones waste brightness headroom by rolling off up to 100% PQ signal level. A brief saturation sweep of the display’s P3 gamut in BT.2100 shows that its HDR color accuracy is fair, albeit just slightly undersaturated in reds and greens. I’ve also noticed that Sony’s HDR display mode doesn’t comply with Android’s standard color management system, and only a few whitelisted apps can properly render HDR videos (primarily Google Photos and Netflix). Many other media players, like VLC, don’t support proper HDR playback on the Sony Xperia 1 II. I was not able to test Dolby Vision performance or compatibility (though the first generation was said to support it), but I reckon it performs similarly, along with HLG.
Conclusion
At about $1,200 U.S. dollars, the display on the Sony Xperia 1 II has simply not wowed me enough to feel like it can be pitted up against the likes of Samsung, OnePlus, or Apple. The rest of the phone can be perfect, but if the display is not captivating enough to me, then it’s a non-starter. Given the issues with tone mapping in Creator mode, I cannot say that it successfully fills its niche as a mobile monitoring tool for all content creators. Tone mapping shadows can be very delicate, and what you see on the Xperia 1 II’s display is simply too light compared to what an actual reference monitor would produce. Regrettably, I haven’t measured its Rec.709 video playback output (which should target a 2.40 gamma power), but if it’s anything like its generic tone mapping, then it would be useless for filmmakers. Since I regard contrast as the most important factor in picture accuracy, I can only recommend using the Standard profile with the white balance set to D65 on this phone, even with its boosted colors.
The Mark II improved in the areas that prevented its predecessor from being considered one of the top phones last year, but it took two steps back, a whole year later when display technology has yet again taken another step forward. Motion blur reduction has absolutely no bargaining chops against a higher refresh rate panel, and the 4K resolution is forgettable unless you frequently consume 4K content on your phone. Those wanting to monitor HDR content may also be upset to see that it’s missing nearly 300 nits of highlight headroom. For casual users, the display is decent with no offensive problems in Standard mode, but content creator or not, I don’t think it’s worth the FOMO (fear of missing out) for what it’s worth, especially when you can get cheaper phones with better displays.
- With the Xperia 1 II, Sony is targeting the content creator niche. While Sony has definitely improved the display quality since last year's Xperia 1, there are better options out there for content creators. Casual users and fans of Sony's Xperia phones, though, won't find the display to be offensive and thus may find the Xperia 1 II to be a worthwhile purchase.
The post Sony Xperia 1 II Display Analysis: Content Creators, Beware appeared first on xda-developers.
from xda-developers https://ift.tt/3kjHksG
via IFTTT
No comments:
Post a Comment