Thursday, November 1, 2018


Samsung Q9FN QLED vs OLED (LG C8; Sony A8F) Comparison:
  • The main strengths of the Samsung Q9FN QLED TV are the brightness output, color saturation in highlights, local dimming algorithm, anti-reflective filter, various gaming features (including low input lag), One Connect Box and no risk of image retention.
  • The strong points that the LG C8 and Sony A8F OLED TVs have in common are the black level, color saturation in shadows, Dolby Vision support, viewing angles, pixel response time.
  • The Sony A8F has a slight advantage over both the LG C8 and Samsung Q9FN when it comes to image processing (including motion interpolation) and sound (due to the Acoustic Surface technology).
  • The LG C8 has a lead in terms of auto calibration functionality (but this requires specialized software and equipment that are sold separately).
Table of contents 1. HDR Picture Quality 2. SDR Picture Quality 3. Image Enhancements 4. Longevity & Viewing Angles 5. Gaming & Sports 6. Sound 7. Inputs 8. Smart TV 9. Design 10. Advanced Features

1. HDR picture Quality

1.1. HDR Brightness Note: Higher is better
HDR Peak Brightness Q9FN: up to 2000cd/m2 LG C8: up to 900cd/m2; Sony A8F: up to 800cd/m2
The Samsung Q9FN can reach up to 2000cd/m2 in small HDR highlights whereas the Sony A8F and LG C8 have significantly lower peak brightness output. Since the goal of HDR is not making the entire image brighter but rather using the luminace capabilities of the TV to make only highlights brighter, thus increasing the dynamic range, the Samsung Q9FN's brightness advantage over the LG C8 and Sony A8F can be observed only in HDR highlights. Any differences in the mid-tones are due to how closely the ST.2084 PQ (Perceptual Quantizer) EOTF (Electro Optical Transfer Function) is followed by the TVs rather than their brightness capabilities. The PQ EOTF tracking is examined in the next paragraph. 1.2. Dynamic tone mapping
Samsung Q9FN LG C8/Sony A8F
Dynamic Tone Mapping No Yes
PQ EOTF Tracking Mid-tones and Highlights are brightened Mostly Accurate
The HDR10 format, which both OLED and QLED TVs support, contains only static metadata, meaning that, in the absence of dynamic tone mapping capability on part of the TV, is prone to keeping mid-tones and shadows compressed, even in scenes without highlights. This can happen if the TV attempts to faithfully track the PQ EOTF curve. The Samsung Q9FN doesn't perform dynamic tone mapping but it's configured to render mid-tones brighter than the PQ EOTF curve calls for, thus mitigating some of the limitations of the static metadata. It should be said, though, that even the 1,000cd/m2 highlights are rendered brighter on the Smasung Q9FN than they should be whereas the LG A8F and Sony A8F attempt to follow to the PQ EOTF curve as close as possible. Furthermore, they feature dynamic tone mapping so that they can optimize the APL on a scene-by-scene basis without deviating from the PQ EOTF curve. Dolby Vision (supported by LG C8 and Sony A8F) and HDR10+ (supported by Samsung Q9FN), on the other hand, have dynamic metadata containing instructions from the content creators regarding the MaxFALL (maximum frame average light level) and other parameters in individual scenes (or even frames), meaning these two HDR formats are able to deliver more accurate picture in terms of the creative intent in comparison to the TV themselves generating the dynamic metadata on the fly. 1.3. Color
Color Saturation in QLED OLED
Highlights Optimal Sub-optimal
Mid-tones Optimal Optimal
Shadows Sub-optimal Optimal
Given that the DCI-P3 coverage for mid-tones is comparable between the Samsung Q9FN, LG C8 and Sony A8F, the variation in color saturation for highlights and shadows is mostly due to the different brightness range on the Samsung Q9FN vs LG C8 and Sony A8F, and the ability to maintain color saturation near the two opposite ends of the grayscale. The Samsung Q9FN is not just able to show brighter colors in highlights due to the approximately 2 times higher peak brightness in comparison to the LG C8 (and Sony A8F), but also to properly saturate them. Quantum dots are used for converting the spectrally broad dichromatic white light produced by the LEDs to trichromatic light with narrow spectral peaks in the red, green and blue regions which is optimized for the color filters. This ensures that primary colors are not contaminated with any of the spectrally broad white light, and color saturation is not affected. Conversely, this is the reason why the LG C8 and Sony A8F tend to struggle with the saturation of bright colors. Although they don't have a backlight that needs to be optimized, hence the omission of quantum dots, they use a 4-subpixel structure in which a white subpixel is added to the traditional red, green and blue ones. As a result, some degree of contamination of the primary colors at higher liminance levels is unavoidable. Similarly, the otherwise pure primary colors on the Samsung Q9FN can be contaminated when mixed with dark gray (instead of pure black) due to the fact that it doesn't have self-emissive pixels that can be turned off, and the quantum dots are not designed to block light either. Nevertheless, the Samsung Q9FN uses a VA-type of panel with full-array local dimming backlight, and is able to achieve very deep black levels by LCD standards although this doesn't fully address the issues with color saturation at low luminosity levels, especially when viewed off-axis. 1.4. HDR formats
Samsung Q9FN LG C8/Sony A8F
Dolby Vision No Yes
HDR10+ Yes No
All three TVs support HDR10 and HLG (Hybrid Log Gamma) formats. The HDR10 format has static metadata whereas the HLG doesn't include any metadata because it's intended to be used mainly in broadcast TV. In terms of the HDR formats with dynamic metadata, the LG C8 supports Dolby Vision out of the box whereas the Sony A8F requires a firmware update that has already been released. The Samsung Q9FN doesn't support Dolby Vision but it's compatible with HDR10+ which also has dynamic metadata.

2. SDR Picture Quality

2.1. Black Level Note: Lower is better.
Level 0cd/m2 Q9FN: ~0.005cd/m2
OLED TVs are emissive whereas QLED TVs, in their current form, are transmissive since they use a backlight and LCD panel (quantum dots are only used for the purpose of optimizing the spectrum of the backlight). In order to display black color, OLED TVs simply need to turn off individual pixels which allows the LG C8 and Sony A8F to reach a perfect black level of 0 cd/m2. This makes the two OLED TVs extremely suitable for a darkened home cinema room where you can appreciate their perfect black level and infinite intra image contrast ratio. The QLED TVs, on the other hand, cannot turn off individual pixels so they need to block light in order to display black color. For that purpose, QLED TV have two polarizing filters and a liquid crystal layer in-between them. The VA type of LCD panel used by the Samsung Q9FN, due to the vertical alignment of its liquid crystals, doesn't alter the light polarization by default, so most of it is blocked which in turn leads to relatively deep black level (in comparison to IPS or TN type of LCD panels). However, since not all light is completely blocked, the Samsung Q9FN resorts to dimming some sections of its backlight in order to improve its black level. As a result, the minimum luminance level on the Samsung Q9FN is ~0.005cd/m2. 2.2. Dimming Zones Note: Higher is better
Dimming Zones 8,294,400 zones Q9FN: ~480 zones (65" class)
The LG C8 and Sony A8F have 8,294,400 self-emissive pixels, meaning the two OLED TVs are able to adjust their luminance in 8,294,400 zones, or 1 pixel per dimming zone. As a result, there are no halos around bright objects against dark background. While the Samsung Q9FN is also able to control blooming artifacts, this comes at the expense of some of the smaller bright objects or details being obscured (depending on your settings for the local dimming feature). The reason being Samsung Q9FN (in the 65-inch class) has only approximately 480 local dimming zones, with each zone consisting of ~17,280 pixels. In other words, the Samsung Q9FN cannot quite match the pinpoint accuracy of the two OLED TVs' light control capabilities. 2.3. Bright Room Note: Higher is better (Brightness headroom shown as relative to a peak white of 100cd/m2; APL stands for Average Picture Level.)
Headroom for OLED QLED
100% APL ~1.5x Q9FN: ~7x
25% APL ~4x Q9FN: ~10x
SDR content is typically mastered for a target luminance of 100cd/m2. All three TVs don't use ABL (Auto Brightness Limiter) within this range, meaning they are all capable of a reference SDR picture quality, without darkening the image as the APL (Average Picture Level) of content increases (given that they're calibrated to 100cd/m2 or so). If you're not using your TV in a light controlled environment, however, the Samsung Q9FN has significantly more brightness headroom than either the LG C8 or Sony A8F. The difference between the QLED and OLED is especially striking with high APL content (such as hockey or some other winter sports, for example) because under these circumstances the Samsung Q9FN can get up to 7 times brighter than the luminance level SDR content is mastered for (which, as previously mentioned, normally is 100cd/m2) whereas the LG C8 and Sony A8F can reach only up to 150cd/m2 in 100% APL scenes, so their brightness headroom might not be sufficient for bright environments but only when watching high APL content (e.g. hockey). When it comes to content with low-to-mid APL (i.e. most movies and TV series), the Samsung Q9FN is able to maintain its advantage in terms of brightness headroom but the LG C8 and Sony A8F perform significantly better than with high APL content, meaning you can watch the vast majority of movies and TV series on the LG C8 and Sony A8F even under bright lighting conditions. 2.4. Reflections
Samsung Q9FN LG C8/Sony A8F
Anti-reflective filter Ultra Black Elite Yes
The Samsung Q9FN has a slight advantage over the LC C8 and Sony A8F in terms of reflection handling. Its anti-reflective filter is made to resemble a moth's eye with tiny uniform bumps that increase its ability to absorb (or re-direct) external light without compromising the light output of the TV. That being said, the LG C8 and Sony A8F perform also quite well in this category.

3. Image Enhancements

3.1. Picture Processing
Sony A8F Samsung Q9FN LG C8
Image processor X1 Extreme Q Engine Alpha 9
Dual database processing Yes No No
The Sony A8F, thanks to the dual database processing capability, has a slight edge over the Samsung Q9FN and LG C8 in terms of upscaling low resolution content. That being said, when the source content has a 720p or 1080p resolution (and the bitrate is adequate), the three TVs' upscaling performance is nearly identical. The Motionflow XR on the Sony A8F tends to create slightly less artifacts when generating intermediate frames, so the motion in not only smoother but fine details remain clear. That being said, the Samsung Q9FN and LG C8 perform very well in this category as well, so they are quite close to the Sony A8F. 3.2. Banding Reduction Note: Independent from Noise Reduction is better
Sony A8F Samsung Q9FN/LG C8
Smooth Gradation Yes, independent from Noise Reduction Yes, alongside Noise Reduction
In terms of dealing with in-source posterization without creating any artifacts, the Sony A8F has the upper hand in comparison to the Samsung Q9FN and LG C8, mainly because it's able to apply the smooth gradation feature independent from the noise reduction filters. This prevents any loss of fine detail in the picture that the Samsung Q9FN and LG C8 may exhibit when they attempt to remove posterization artifacts due to the fact their de-banding filters work in conjunction with the noise reduction ones.

4. Longevity & Viewing Angles

4.1. Image retention/burn-in protection
Not needed for an LCD panel Automatic & Manual detection and correction of voltage irregularities; Pixel Shift; (LG C8: Logo Luminance Adjustment)
The Samsung Q9FN, due to the LCD panel, is generally not at risk of exhibiting image retention or burn-in. When it comes to the LG C8 and Sony A8F, it should be said that the OLED panel may exhibit some temporary image retention, but only if a static image (or a static portion of content) is displayed for long periods of time. This is the reason why the two OLED TVs are configured to automatically run a short compensation cycle after accumulating a predefined number of screen-on time. During this cycle they measure the voltage supplied to different areas of the panel and correct any irregularities, thus the image retention is cleared and the panel uniformity is optimized. You can manually start a longer compensation cycle that takes more than an hour to complete if you're exhibiting more prominent image retention or uniformity issues but it's not recommended to use this function more than once per year. The Sony A8F and LG C8 are also equipped with pixel/screen shift option which intends to prevent image retention happening in the first place by shifting slightly the image after some time. The Logo Luminance Adjustment can only be found on the LG C8, though. 4.2. Viewing Angles Note: Wider is better
Viewing Angles Narrow Wide
Due to the OLED panel structure, in which the light source is placed almost immediately to the surface of the display, the viewing angles on the LG C8 and Sony A8F are wide. They are able to maintain the black level when viewed off-axis. The brightness decrease is minimal but there is some color shift, however. That being said, it only becomes noticeable past 45 degree off-axis. The Samsung Q9FN, on the other hand, due to the VA-type of LCD panel starts exhibiting a raise in the black levels almost immediately when viewed off-axis, in addition to losing brightness fairly quickly. Furthermore, the colors start to lose saturation earlier than in OLED TVs.

5. Gaming & Sports

5.1. Input Lag Note: Lower is better
Input Lag in Samsung Q9FN LG C8 Sony A8F
Game Mode ~15ms ~21ms ~31ms with 4K; ~47ms with 1080p
Game Motion Plus ~24ms N/A N/A
Variable refresh rate ~7ms N/A N/A
The Samsung Q9FN and LG C8 have very low input lag with both 4K or 1080p signal. When in Game mode, the Samsung Q9FN is able to register your input as soon as 15.4 ms so it has a slight advantage over the LG C8 which takes about 21 ms. The Sony A8F, on the other hand, has close to 31ms of input lag when fed with 4K signal, and even more substantial delay with 1080p signal. The Samsung Q9FN has a Game Motion Plus feature which is designed to interpolate frames while keeping the input lag as low as possible. When the Game Motion Plus is enabled, the input lag on the Samsung Q9FN is about 24ms. This is especially significant in the context of the fact that the input lag on the LG C8 and Sony A8F reaches unplayable levels if any frame interpolation is used. 5.2. Gaming
Samsung Q9FN LG C8/Sony A8F
FreeSync support Yes, in 1080p up to 120Hz (after firmware update) No
Only the Samsung Q9FN supports (after a firmware update) the FreeSync technology (but only in 1080p resolution and up to 120Hz refresh rate) which uses adaptive synchronization in order to prevent screen tearing. Provided you've installed the update, you can choose between two intervals: either 90Hz-120Hz, or 48Hz-120Hz. 5.3. Sports
Instantaneous Pixel Response No Yes
The LG C8 and Sony A8F, due to their OLED panels, are able to complete all pixel transitions nearly instantaneously. The lack of any blur between the frames means that they don't suffer from ghosting or double image artifacts during fast motion but also makes them prone to stuttering. However, this doesn't affect sports programming because stuttering is mainly noticeable with low frame rate content (e.g. 24 fps) such as movies. The Samsung Q9FN doesn't have an instantaneous pixel response time because it uses an LCD panel, and reorienting the liquid crystals takes slightly more time than switching OLED pixels. That being said, the Samsung Q9FN still manages to complete the pixel transitions before the next refresh cycle so that there are no dark trails following fast moving objects. Furthermore, it's less prone to exhibiting stutter with 24fps content than the LG C8 and Sony A8F but, as previously said, this doesn't affect sports broadcasts because they're typically in 60fps or 50fps, depending on where you live.

6. Sound

6.1. Speakers Direction Note: Front-firing is better
Sony A8F LG C8 Samsung Q9FN
Direction Front-firing (Acoustic Surface) Down-firing Down-firing
Sound Tuning No Yes No
The LG C8 and Samsung Q9FN have traditional down-firing speakers whereas the Sony A8F uses the Acoustic Surface technology. There are a total of 4 actuators (2 per channel) used for invisibly vibrating the screen in order to produce mid-range and high frequency sounds. The sound is therefore directed, instead of reflected, towards you. Furthermore, the fact that the Sony A8F's screen itself is producing sound allows for a more realistic experience where the dialogues can be directly connected to the characters on the screen that are speaking. The low frequency band is reproduced by the two sub woofers on the back of the Sony A8F. The C8's stand has a cutout designed to aid the sound redirection form the down-firing speakers towards the front of the TV, thus improving the clarity of voices and dialogues. Furthermore, the C8 has a sound tuning feature that uses the Magic Remote's built-in microphone to measure and analyze the acoustics of your room in order to provide optimal sound for the specific conditions of your listening environment. 6.2. Audio System
Samsung Q9FN LG C8 Sony A8F
Speaker system 4.2-Ch 2.2-Ch (2 Full Range Drivers; 2 Sub woofers) 2.1-Ch (4 Actuators; 2 Sub woofers)
Total audio power 60 Watts 40 Watts 50 Watts
Dolby Atmos Decoder No Yes No
There are 2 sub woofers on each of the three TVs but the bass is somewhat deeper on the LG C8 and Sony A8F in comparison to the Samsung Q9FN. Furthermore, the two OLED TVs are able to get a bit louder than the Samsung Q9FN but also exhibit slightly more distortion. The LG C8 has a Dolby Atmos decoder but it doesn't have any integrated height speakers, meaning it has to emulate 3-dimensional sound via its 2.2 channel speaker system. Alternatively, you can pass-through Atmos tracks via the HDMI ARC on the LG C8 to a compatible receiver or a sound bar.

7. Inputs

7.1. Inputs Location
Samsung Q9FN LG C8/Sony A8F
External Box Yes, One Connect Box No
Cable Management One Invisible Connection Basic
The Samsung Q9FN has all the inputs, power supply and electronics housed inside the external One Connect Box. Only the 16.4 ft long fiber optical cable dubbed One Invisible Connection that carries both power and video signal has to be plugged in the TV. In contrast, the LG C8 and Sony A8F have their inputs and electronics at the back of the TV. The Sony A8F has more advanced cable management system than the LG C8, including removable panel covers at the back so that it can achieve clean rear look (on par with the Samsung Q9FN). 7.2. Bandwidth of HDMI & USB Inputs
Samsung Q9FN LG C8 Sony A8F
Full-bandwidth HDMI 2.0 Inputs 4/4 4/4 2/4
USB Ports 3 (USB 2.0) 3 (USB 2.0) 2 (USB 2.0) + 1 (USB 3.0)
There is no difference in the number of HDMI inputs on all three TVs but it should be said that not all HDMI inputs on the Sony A8F are full-bandwidth. Even though only two (out of the four) HDMI inputs on the Sony A8F are full-bandwidth, it should be said that HDCP 2.2 is supported on all four HDMI inputs which is also the case with the Samsung Q9FN and LG C8. In terms of USB ports, only the Sony A8F has a USB 3.0 port in addition to two USB 2.0 ports whereas the Samsung Q9FN and LG C8 only have USB 2.0 inputs (each TV has 3 of them).

8. Smart TV

8.1. Smart TV Platform
Samsung Q9FN LG C8 Sony A8F
Smart TV System Tizen WebOS 4.0 Android 7.0
Both the Samsung Q9FN's Tizen Smart TV system and the LG C8's web0S are slightly more intuitive to use than the Sony A8F's Android TV but there are fewer apps available for installation. That being said, all three TVs come with Amazon Video and Netflix apps pre-installed. The Samsung's One Remote control doesn't have any dedicated number buttons whereas the LG's Magic Motion remote and Sony TV remote control do include them. The LG motion remote control supports point-and-click functionality, and has a scroll wheel, thus making navigation through menus and content easier than the Sony's traditional remote control. 8.2. Voice Control
LG C8/Sony A8F Samsung Q9FN
Voice Assistant Google Assistant built-in Bixby
All three TVs have remotes with a built-in microphone and an integrated voice assistant, so that you can interact with your TV using voice commands. Furthermore, you can use an Amazon Alexa device (sold separately) to control some functions on all three TVs via voice commands. The initial setup process differs between the three TVs, however. In addition to the Amazon Echo mobile app, you'll need either the SmartThings or the LG SmartThinQ mobile apps (with the Samsung Q9FN and LG C8, respectively). The LG C8 can be controlled via two Alexa skills: "LG SmartThinQ – Smart Home" and "LG SmartThinQ". The former allows Alexa to directly control your TV, whereas the latter is a custom skill type which provides you with more control features than the former since Alexa redirects your voice commands to the LG SmartThinQ system. You'll also need to update the firmware on the LG C8 in order for the Amazon Alexa compatibility to be added. When it comes to the Sony A8F, there is an app on the TV's Home Screen called: "TV Control Setup with Amazon Alexa". You'll also need to enable the "Sony's Android TV" skill in the Amazon Alexa mobile app, then link your accounts, and finally ask Alexa to discover your devices.

9. Design

9.1. Wall mounting
VESA Compatibility
Samsung Q9FN Sony A8F LG C8
65" 75": 400x400 55": 300x200; 65": 300x300 55" 65": 300x200; 77": 400×200
The LG C8 and Sony A8F have an ultra thin top half (due to the OLED panel) but all their inputs and electronics are placed at the bottom half of the back panel which makes them overall thicker than the Samsung Q9FN. As a result, the LG C8 and Sony A8F cannot be mounted entirely flush to a wall (there will be inevitably some distance between the extremely thin top half and the wall). The Samsung Q9FN, on the other hand, has all the inputs and TV circuitry inside a separate box which means the entire panel can be mounted flush to a wall using the optional No Gap Wall Mount (sold separately). 9.2. Table top mounting
Sony A8F Samsung Q9FN LG C8
Table To Stand Dark Silver Slate Simple Plus Streamlined Alpine
Clearance beneath the display less than 0.2 inches (55" 65" class) 1.4 inches (65" class) 1.3 inches (75" class) 2 inches (55" 65" class); 2.4 inches (77" class)
Optional Stand No Gravity or Studio Stand for 65" class (sold separately) No
The Sony A8F sits almost flush to a table top surface because its dark silver slate stand provides less than 0.2 inches of clearance beneath the display, meaning you cannot place a sound bar directly in front of the TV. The Samsung Q9FN provides more clearance beneath the display when placed on its table top stand: about 1.4 inches (65-inch class). That being said, the front portion of the stand extends further ahead than the LG C8 and Sony A8F so a sound bar cannot be placed directly under the TV. The Samsung Q9FN (in the 65-inch class) is compatible with two other stands: Gravity & Studio (sold separately). The clearance beneath the LG C8 is approximately 2 inches but due its alpine form factor, the front portion also extends forward (although less than Samsung Q9FN).

10. Advanced Features

10.1. Calibration
CalMAN Auto Calibration support
LG C8 Samsung Q9FN Sony A8F
Full access to 3D and 1D LUTs Basic (2- & 10-point grayscle, CMS) No
The CalMAN software (sold separately) by SpectraCal can be used for auto calibrating the Samsung Q9FN and LG C8 but not the Sony A8F. To perform auto calibration, however, you'll need some specialized equipment, such as colorimeter and pattern generator, that are also sold separately from the TV. There is a difference between the Samsung Q9FN and LG C8 in terms of how they accommodate the auto calibration process. The Samsung Q9FN shares some of the menu settings that are already user accessible (e.g. 2-point white balance, 10-point grayscle, color management system) with the CalMAN software whereas the LG C8 provides this software with a full access to the TV's internal 3D Cube and 1D LUTs (Look Up Tables). The LG C8 uses a 33x33x33 3D Cube LUT which means it can store 35,937 color data points used for color corrections. Not all of them need to be measured, though. Profiling a fraction of the total number is sufficient for generating accurate correction data, meaning that remaining color data points are calculated. The profile and calculate method applies only to the 3D LUTs, though, whereas the 1D LUTs are generated by the means of measure and adjust. Any of the 1.07 billion colors on the LG C8 without a corresponding correction value in the 3D look-up table are interpolated. The same applies to the 1D LUT's 1024 correction points that are interpolated from either 26 or 42 measured points. The relative large size of the LG C8's 3D LUT means that less color interpolation is done (in comparison to a 17x17x17 3D Cube LUT, for example), and more importantly: when colors do need to be interpolated, this can be done with higher accuracy which minimizes quantization errors. Although the 1D LUT is placed after the 3D LUT in the video processing chain, it has to be calibrated first. The 1024 entries (with 12-bit precision per entry) on the 1D LUT provide more control over near-black (not least because they are not spaced evenly in order to correct more effectively any problems LG OLED TVs might have when transitioning from black to dark gray), as opposed to calibrating the grayscale and gamma only via the 3D LUT alone. The LG C8 can be auto calibrated (for five different SDR picture modes, including Game mode) in a non-linear light domain, without having to convert gamma encoded signals to linear light signals, which is required for saturation and hue adjustment in a traditional color management system, thus the LG C8 can avoid any quantization errors. When it comes to HDR, there are 3 modes for HDR10/HLG and 3 modes for Dolby Vision with individual 1D LUTs. Tone-mapping is disabled during the auto-calibration process meaning the HDR calibration is done in a traditional 2.2 gamma space instead of a PQ (used by HDR10 and Dolby Vision) or HLG (Hybrid Log Gamma) space. This allows to have the same calibration settings for both HDR10 and HLG, even though they use different transfer functions, as well as to prevent signal processing from interfering with the auto calibration process for HDR.

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