The KDL-40HX853 is one of the few edge-lit LED LCD TVs that feature local dimming, meaning that different zones on the panel can be independently illuminated or dimmed based on content to achieve deeper blacks without compromising overall brightness. On the Sony, this technology is accessible via the [LED Dynamic Control] option in the user menu, which comes in three settings: “Off“, “Low” or “Standard“.
When asked to display full-field video black, the HX853 would automatically dim its LEDs: with [LED Dynamic Control] off, black level dropped to 0.0057 cd/m2; whereas with local dimming activated, the LEDs would switch off totally. This auto-dimming is not as intrusive as it sounds, since it’s only triggered upon presentation of a full black screen (even the presence of a pause icon would defeat it), and Sony has cleverly implemented a slight time delay to make the effect more subtle. We were certainly not bothered by it at all during our time spent with the TV.
Measuring black level on an ANSI checkerboard test pattern gives a more accurate indication of real-world performance. Without the help of local dimming (i.e. with [LED Dynamic Control] disabled), the Sony KDL40HX853′s ANSI black level came in at 0.0723 cd/m2. We expected local dimming to deepen the blacks, and true enough, setting [LED Dynamic Control] to “Low” and “Standard” not only improved the figure to 0.0547 and 0.0527 cd/m2 respectively, but also alleviated any residual backlight uniformity issues (e.g. clouding, backlight bleed).
Because the number of dimming zones is significantly less than the number of pixels available on the 40HX853, it’s inevitable that brighter elements overlaying a black background on screen would be surrounded by a faint, lighter halo. However, we didn’t feel that this was a major issue even during critical viewing: we’d gladly take a small amount of circumferential halos (which only surfaced when there’s a bright object against a black background) than put up with worse blacks and more clouding.
With [Motionflow] disabled, motion resolution (based on Chapter 31 of the FPD Benchmark Software test disc) on the Bravia KDL40HX853 was 300 lines, which is par for the course for a vanilla LCD panel unassisted by motion-compensated frame interpolation (MCFI). To engage [Motionflow], we were presented with no less than five settings: “Clear“, “Clear Plus“, “Impulse“, “Standard” and “Smooth“. After some quick tests, we ruled out the last two pretty much straight away, because they introduced obvious soap opera effect into 24p movies, and manifested more interpolation artefacts like tearing and blocking. Should you insist on using them, you can expect motion resolution of around 950 lines .
Selecting any of the other three settings boosted motion resolution even further to 1080 lines. “Impulse“, which seems to be using an aggressive form of backlight scanning/ black frame insertion, delivered the clearest motion without any noticeable artefacts, but suffered from (in our opinion) an unacceptable amount of flicker and brightness drop. “Clear Plus” appeared to be a middle ground between “Clear” and “Impulse“, involving a slight hit in luminance. By process of elimination, we felt that [Motionflow] “Clear” is probably the best choice for day-to-day video content: it improves motion clarity without introducing significant interpolation artefacts nor affecting overall picture brightness.
The Sony KDL-40HX853 is one of the best HDTVs we’ve seen in upscaling SD content to be fitted on its 1080p panel. When fed with an interlaced (576i) SMPTE RP-133 test pattern, the LED TV captured all the details in full, and then displayed them crisply without any ringing. It also correctly detected and processed 3:2 cadence over 480i as well as 2:2 over 576i, ensuring that standard-def movies are presented without any resolution loss nor jaggies.
Video-mode deinterlacing was decent rather than top-notch – the third block in the bouncing bars test pattern betrayed obvious jaggies – but we’d be lying if we said we picked up many jagged edges in real-life viewing. We’ve rarely seen standard definition looked as good as it did on the HX853, owing to the superb upconversion and well-saturated colours.
If SD looked good on the Sony KDL40HX853, then the first word that pops to mind to describe its HD performance is “spectacular”. Without any undefeatable noise reduction nor edge enhancement at play, 1080i/1080p images absolutely dripped with detail, breathing a sheen of exquisite finesse into every type of high-def content – be it Blu-ray film or off-air HD broadcast – displayed on screen. Sony clearly understands there’s no need to tamper with what is already a pristine high-definition source, providing users with the choice of opting out from any unnecessary processing – we believe this is a very welcome byproduct of the company’s involvement in content creation and post-production through its Sony Pictures Entertainment arm.
While not the last word in outright black-level response, the KDL-40HX853 churned out sufficiently deep blacks for colours to “pop” in a vibrant yet realistic fashion. Another strength of the LED TV is its ability to render shadow detail with authority: when watching dark scenes, we never got the feeling we were missing out on something, nor were the near-black shades so revealing that authenticity was lost. All the nuances in the dark just flowed into our eyes so easily, which makes a refreshing change not only from lesser LCD-based displays, but also from plasma TVs which typically feature variable gamma response.
Viewing angle was very decent for an LCD TV (not IPS level, but close): had it not been so, more people would probably be put off by the panel’s 6-degree-backward tilt. As always, the Sony handled 1080p/24 video signal impeccably without judder even with [Motionflow] switched off.
The Bravia KDL40HX853 possesses almost every necessary ingredient to deliver a first-rate 3D viewing experience. Accurate greyscale and colours after calibration? Check. Full HD 3D resolution granted by active-shutter glasses (ASG) technology? Check. Judder-free rendition of all sorts of tri-dimensional material including frame-packed, side-by-side, 50Hz, 60Hz or 24p? Check.
There remained a couple of niggles though. First, the Sony TDG-BR250 active-shutter 3D glasses need to be worn horizontally level with the screen – even a slight tilt of your head beyond 10 degrees left or right will taint the extra-dimensional picture with an intolerable amount of discolouration, crosstalk and loss of 3D depth.
The second issue is crosstalk. For some reason the KDL-40HX853 exhibited more ghost images in 3D mode compared to high-end 3DTV models from Panasonic and Samsung. The amount of crosstalk varied from scene to scene, depending on whether there are brighter objects contrasted against a dark background, and the stereoscopic distance (e.g. very far or very near to screen) of these elements. We sampled a number of 3D Blu-ray movies on the television: titles which are mostly bright (John Carter) or have subtle 3D depth (Tron: Legacy) were generally crosstalk-free; whereas night scenes in How To Train Your Dragon and Tangled (in particular the infamous floating lanterns sequence) revealed unmistakable crosstalk.
Appreciating that the Sony HX853 and the TDG-BR250 eyewear still use infrared (IR) frequency to communicate with each other for 3D synchronisation, we removed all other devices that could potentially interfere with the signal from our test room in an attempt to minimise crosstalk, but to no avail. We also experimented with the [3D Depth Adjustment] and [3D Glasses Brightness] controls in the [Display] > [3D Settings] submenu. Bumping the former up to “+1” reduced crosstalk in some scenes, but increased it in others with different stereoscopic depth, so we left it at its default value of “0“. As for the latter, we settled on “Low“, since higher settings not only made crosstalk more visible, but also aggravated backlight non-uniformity (clouding).
Sony has struck gold with the Bravia HX853 series – between the 40″ and 55″ models they’ve brought us the best LCD-based HDTVs we’ve seen this year in terms of picture and sound quality. Despite some mild colour inaccuracies (which most viewers won’t notice), the KDL40HX853 is a fantastic 2D performer in both SD and HD, with its upscaling prowess and stunning high-def detail being particular highlights.
We’re not as enthusiastic about its 3D capabilities due to crosstalk, but the TV’s other strengths more than make up for it, especially when you take into consideration its competitive price point: the KDL-40HX853 is the first Sony Bravia flagship television ever to be available below the psychologically important £1000 mark since we started testing TVs. While plasmas still hold the upper hand in black-level performance and colour accuracy, they are no longer produced in screen sizes less than 42 inches, leaving the Sony KDL40HX853 unchallenged to reign supreme in the 40-inch size class.
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