Like the outgoing Sony HX853 series, the KDL-55W905A uses edge LED backlight technology that is assisted by pseudo-local dimming to deliver deeper blacks without dampening bright whites. The aggressiveness of the dimming algorithm is adjustable via the [LED Dynamic Control] option which comes in 3 settings: “Off“, “Low” and “Standard“.
First, let’s talk ANSI measurements with a 4×4 checkerboard pattern. With [LED Dynamic Control] disabled, black level came in at 0.049 cd/m2. Both the “Low” and “Standard” settings returned the same figure of 0.042 cd/m2.
Like most edge LED TVs, the Sony W9 automatically dims its side-mounted LEDs when asked to display a full black screen. Black level would drop to around 0.01 cd/m2 if [LED Dynamic Control] was not enabled. If it was, the LED bulbs would shut off completely.
The auto-dimming can be defeated by even a small amount of lit pixels on screen. Under this scenario (combination of a full-field black pattern and a pause icon from a Blu-ray player), the KDL55W905A’s blacks measured 0.049 cd/m2 with [LED Dynamic Control] “Off“; and 0.01 cd/m2 with “Low“. The “Standard” setting was quite aggressive: only the bottom portion of the LCD panel (where the pause icon is) would be illuminated, which in our case did not extend to the centre of the screen where our light measurement meter was placed. This gave us a black-level reading of 0 cd/m2 which is not truly representative, as well as caused fairly obvious haloing effect around the pause icon, since the number of dimmable zones is significantly less than the number of pixels on the Bravia W905A.
As with most dimming technologies, we spotted some faint brightness fluctuations in near-black areas (specifically between 0% and 10% stimulus) on test patterns with [LED Dynamic Control] enabled, but these never bothered us in real-life viewing. Sony has sensibly incorporated a minor time delay and fade-away effect into the full-black-screen auto-dimming, which makes it more subtle and less jarring.
What does it all mean? Strange as it may sound, the pseudo-local dimming (we use this phrase to differentiate it from true, physical local dimming found on full-array LED televisions like the Sony HX950 and the Samsung S9) on the Sony KDL-55W905A was less effective than that on its predecessor the HX853/HX850, simply because the native unassisted black level was better on the W9.
Engaging [LED Dynamic Control] is especially useful if your W905A is beset by screen uniformity issues like clouding or backlight bleed. Our review sample wasn’t, although there remained mild “vignetting” along the edges of the screen, not to mention a slight “dirty screen” effect noticeable during panning shots against evenly toned backdrops. These are not uncommon on edge-lit LED LCDs, considering how a limited number of side-mounted LEDs have to illuminate the entire LCD panel.
Between the two available [LED Dynamic Control] settings, we preferred “Low“. “Standard” uses a more aggressive dimming algorithm, resulting in visible halos (on certain scenes) and hard cut to absolute black. Both delivered similar levels of black-level improvement when it came to ANSI contrast measurements, hence there’s almost no logical reason to choose “Standard” over “Low“.
Sony’s motion-compensated frame interpolation system is called [Motionflow], which comes in 6 flavours on the KDL55W905A: “Standard“, “Smooth“, “True Cinema“, “Clear“, “Clear Plus” and “Impulse“. The first two introduced soap opera effect into 24p movies, so we rejected them immediately. For the sake of completeness, motion resolution (as determined through the horizontally scrolling test chart in the FPD Benchmark disc) were 850 and 900 for “Standard” and “Smooth” respectively. “True Cinema” did not increase motion resolution at all beyond the stock LCD level of 300.
The last three options increased motion resolution to 1080 lines. The “Impulse” mode uses backlight scanning/ black frame insertion techniques to “reset” our retinal persistence and improve the perceived clarity of moving objects. No interpolation is applied in this mode, so there’s no interpolation artefacts, but we did see some double edge ghosting on selected panning shots.
The Sony W905′s “Impulse” mode implementation caused significantly less flicker to our eyes compared to last year’s HX853, which is a massive plus. However, there’s still a sizeable amount of brightness drop: with “Impulse” mode engaged, we only managed to coax a maximum luminance of 98 cd/m2 out of the KDL-55W905A with both [Backlight] and [Contrast] bumped up to “Max“. This pretty much rules it out for daytime viewing when it’s arguably most needed, since most live sports broadcasts (which benefit most from higher motion resolution without interpolation artefacts) take place during the day.[Motionflow] “Clear” interpolates without causing 24fps film-based content to look like hyperrealistic, ultra-smooth video. “Clear Plus” appears to be a midway setting between “Clear” and “Impulse” – there’s some interpolation going on, and a small decrease in luminance. Both “Clear” and “Clear Plus” are viable options to boost motion resolution without evident side effects, with the former being more practical for daytime use.
We ran our usual tests to see how the Sony W905 processed standard-def material. Scaling quality was in the upper tier: all the details in the interlaced (576i) SMPTE RP-133 chart were captured in full, and then upconverted crisply to be fitted on the 1080p panel. There’s more ringing around high-contrast edges compared to Samsung’s scaling algorithm, which can exaggerate compression artefacts like mosquito noise as well as intra-content edge enhancement. Personally we still have a slight preference for Samsung’s really forgiving method of upscaling standard-definition content, but Sony’s effort is an excellent alternative – sharp and detailed SD images are the order of the day as long as you adopt a sensible viewing distance (7 feet away from screen), and the video source is up to scratch.
For film-based material, the KDL55W905A passed the 3:2 (NTSC) and 2:2 (PAL) cadence tests in HQV Benchmark, but with the latter did lose the lock occasionally during real-world viewing (line twitter appeared from time to time in the last chapter of Bridget Jones: The Edge Of Reason UK DVD).
As for video-mode deinterlacing, the Sony 55W9 evinced more jaggies – particularly obvious on the third block of the bouncing bars pattern in HQV Benchmark – than high-end HDTVs from Panasonic and Samsung, though these jagged edges rarely reared their ugly heads in real-life viewing.
High-def content – whether from Blu-ray or Freeview/Freesat HD broadcast – looked nothing short of stunning on the Sony KDL-55W905A. The sufficiently deep blacks (by LED LCD standards) and 2.4 gamma gave images a highly satisfying, contrast-rich appearance, augmented by a very smooth transition from dark to bright that simply oozed realism. Presentation of fine detail was top-notch, with no underhanded noise reduction or edge enhancement to prevent any delicate intricacy within the content from shining through on screen.
A quick note on 2.4 gamma. While we loved that Sony is targeting this value by default in [Cinema 1] mode, shadow detail may appear too dark on screen in the presence of competing ambient light, such as in a bright or even moderately-lit room. This is not helped by the default [LED Dynamic Control] setting of “Standard” whose dimming algorithm is quite aggressive. If you’re having problems with crushed shadow detail on your W905A, try increasing [Gamma] to “0″“, and disabling [LED Dynamic Control].
Colours were by and large well-saturated and natural-looking, as long as [Live Colour] was left off. We initially thought [Live Colour] “Low” would be a viable option judging from what we measured during calibration, but we were wrong – engaging the setting caused faces to appear sun-baked in several clips we sampled mainly from off-air broadcasts. With [Live Colour] disabled, green did look a touch pale, but most viewers probably won’t be able to tell outside of a side-by-side comparison with a reference display.
Sony’s [Motionflow] technology has consistently been the one that exhibited the least amount of interpolation artefacts among MCFI (motion-compensated frame interpolation) systems from major TV brands over the past few years, and the Bravia W9 upheld this tradition when we treated ourselves to a few football matches including a couple of cup finals in front of the big screen. [Motionflow] “Clear” was the most versatile setting: “Standard” and “Smooth” introduced more artefacts (not to mention soap opera effect for film-based content like movies and 24p dramas); while “Clear Plus” and “Impulse” both entailed a brightness hit. Like all flagship Sony Bravias since 2008, the 55W905A handled 1080p/24 signal from Blu-ray discs without judder even with [Motionflow] switched off.
All this picture quality goodness comes with a major caveat though: you really need to sit directly in front of the television to enjoy the full benefit. Even for a VA-type LCD panel, the KDL55W905A’s viewing angles seemed particularly narrow, both horizontally and vertically. In fact, go beyond 20° off-axis, and you’ll be greeted with contrast and colour desaturation – we could hardly believe we were watching the same picture whenever we stood up or shuffled to one side.
We’re not sure if our review unit is representative of retail sets available to buy in stores, but you’d be well-advised to visit your local Sony dealer to see for yourself. Another factor is how sensitive you are to such shifts in colour and contrast… perhaps you’ll be able to tolerate it better than we did.
The KDL-55W905A ships with four pairs of 3D glasses included, which must be a first for an active 3DTV. The supplied TDG-BT400A active-shutter glasses (ASG) use Bluetooth technology instead of last year’s infrared, which provides more stable synchronisation, and does not require line of sight. This might explain the W905′s reduced crosstalk versus the HX8 series.
Talking of which, the recently released Spears & Munsil HD Benchmark 2nd Edition disc offers a useful test pattern for visual evaluation of crosstalk in an objective manner. For maximum accuracy, the actual gamma of the 3D TV needs to be known – we obtained this value during calibration in 3-D mode. While we were at it, we also neutralised the green tint imparted by the ASG lenses by primarily adjusting the G-Gain control.
But back to crosstalk. According to the new Spears & Munsil chart, the Sony KDL55W905A’s crosstalk level was deemed to be 3%. We’ll be carrying out this measurement on all HDTVs and projectors we review going forward: as more data are accumulated, we’ll be able to see where each display device stands in terms of crosstalk. For now, our subjective assessment is that there remained fleeting instances of crosstalk on the Bravia W905A, but it’s improved over last year’s HX853, and certainly did not detract from a thoroughly gratifying extra-dimensional viewing experience due to the glorious full HD 3D resolution, relatively accurate colours (after calibration), and reasonable brightness.
When we placed our Leo Bodnar input lag tester on the generated flashing box with the Sony KDL-55W905A set to [Game Mode], we were bowled over by the returned figure of 19.6ms, the lowest we’ve recorded since we started using the device. Seeking to verify this unheard-of level of gaming responsiveness, we then used the more conventional high-speed camera/ digital timer method, which showed the W9 lagging by merely 8ms (half a frame) compared to a CRT display.
This is an utterly outstanding achievement, especially on a flagship model like the W905A. From our past experience, the more advanced the TV, the more complex the video processing, and the higher the input lag, but somehow Sony has managed to program its [Game Mode] to bypass the majority of the circuitry, providing gamers with an almost surreal, blazingly fluid degree of responsiveness. Is it a coincidence that the Japanese firm is responsible for some of the best-selling game consoles of all time (PS2 and PS3) which are soon to be joined by the next-gen PS4? We think not.
To put the numbers that have been captured using the high-speed camera/ digital timer method into context, the input lag on the fastest Panasonic and Samsung plasmas – which we used to routinely recommend as the best gaming HDTVs owing to an unbeatable combo of low lag and high motion resolution – was 16ms. The Bravia KDL55W905 came in at 8ms, which is 50% less. The previous record holder was incidentally another Sony, namely the entry-level V4000 LCD television on which we couldn’t detect any lag at all back in 2008. The baton has been passed on, and this is something hardcore gamers everywhere should celebrate.
Of course, being an LCD-based HDTV, the Sony W9 is not free from motion blur inherent to LCD display technology, but we think that low input lag is by far the most important attribute that contributes to an enjoyable gaming experience (alongside useful squad members). If you seek better motion clarity, you can opt to engage the only [Motionflow] setting available in [Game Mode], namely “Impulse“. On our review sample, this raised the Leo Bodnar lag tester result to 30ms, which is still superb by all accounts. That said, [Motionflow] “Impulse” in [Game Mode] appeared to exhibit more flicker than in [Cinema 1] mode, and there’s always the drastic drop in brightness – we didn’t think it was worth the tradeoff.
The Bravia KDL-55W905A is yet another fantastic HDTV from Sony that flies the LED LCD flag high. Although we are again disappointed by the relative lack of advanced calibration controls compared to rival premium TVs, this is partially offset by the accurate out-of-the-box greyscale and colours which, on the whole, ranks as the best we’ve measured on any 2013 flat-screen television so far. That the display hits 2.4 gamma by default in its most accurate [Cinema 1] picture preset is just icing on the cake, delivering pictures that are lusciously rich in image contrast.
The Sony W9 is one of a select range of Bravia LED TVs blessed with Triluminos Display technology whose on/off state and intensity can be toggled using the [Live Colour] control in the [Advanced Settings] submenu. We didn’t find the feature useful for regular content, though it may work better with Sony’s “Mastered in 4K” Blu-rays which are meant to support xvYCC extended colour space.
Perhaps the biggest flaw on the Sony KDL55W905A we tested was its restricted viewing angle which we’d be the first to admit may be an issue specific to our review sample. If you’re thinking about buying the W905, we recommend that you audition the TV first at your local Sony Centre, paying particular attention to the viewing angles in both the vertical and horizontal axis. Perhaps retail sets aren’t affected as much, or you may not be as sensitive as we are to changes in colour and contrast – we certainly wouldn’t want you to miss out on the wonderful picture quality that the W905A is capable of providing when viewed straight on.
Of course, viewing angle is probably less of an issue when it comes to console gaming, which is arguably as solitary an activity as you can get involving a TV (we’re referring to sitting alone in front of the screen, rather than playing online multiplayer games). With [Game Mode] enabled, the Sony KDL-55W905A is easily the best gaming HDTV we’ve seen to date, thanks to the lowest input lag on record, full 4:4:4 reproduction (for PC games), and zero risk of image retention or screenburn (unlike plasmas). Should you wish to reduce the motion blur typical of LCDs, Sony even offers the option of engaging [Motionflow] “Impulse” in [Game Mode], but from our experience this introduced a bit too much flicker and brightness dip for our liking.
Standard-definition material was upscaled splendidly by the Sony KDL55W905A, raising our expectations that the Japanese manufacturer’s upcoming X9 Ultra HD 4K TVs will do similarly well with “regular” 1920×1080 content (which will make up the majority of viewing while native 4K content is still thin on the ground). It’s shaping up to be an exciting year for Sony, and the company couldn’t have delivered a better opening salvo than the Bravia W9.
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