Note: Our Sony KDL-55HX853 review sample was calibrated using Calman Professional, the industry-leading video calibration software.
After selecting the [Cinema 1] mode and shutting off any picture processing options which were compromising the accuracy and quality of the overall image, we ran some Greyscale tracking measurements to see how natural the HX853′s overall colour was.
|Pre-calibration RGB tracking and delta errors (dEs)|
Pre-calibrated image quality didn’t have any hugely obvious colour tint visible, owed to the fact that grey shades with too little green in them are much easier to ignore than those which have too much of the colour. We were fairly happy with the picture quality in this state, although it did appear a little blue and cool-looking to our TV-grizzled eyes.
|Post-calibration RGB tracking and dEs in [Cinema 1] mode|
We were able to achieve visibly perfect Greyscale tracking in high-end shades, but as usual for Sony LCD TVs, the low-end white balance controls on the KDL-55HX853 are far too coarse, meaning we had to leave them as they were: any adjustment would trade one excess of colour for another. We were left with dark areas being tinted purple-blue – we felt this was better than tinting them red or green, which would be more visible. It’s a shame, because this is likely to give dark scenes a colder feeling.
The most bizarre thing about the coarse white balance calibration controls relates to what we already discussed with the [Smooth Gradation] feature: its presence indicates that the Sony KDL-55HX853 has some sort of high bit-depth video processing – 10-bit, 12-bit, perhaps even 14-bit – on board. That should give us PLENTY of head-room to make adjustments to low-end Greyscale, and we don’t doubt that the hardware inside the HDTV is capable of perfect low-end accuracy: it seems to be the design of the menus that’s holding things back, which is pretty frustrating.
|Gamma curve in [Cinema 1] mode||Corresponding gamma tracking|
Typically for Sony Bravia LCD televisions, we managed to get excellent gamma performance out of the HX853. However, the different options greatly affect measured gamma.
We started by selecting [LED Dynamic Control]: “Standard”, since this gave the deepest black levels with dark content – in other words, the most aggressive LED dimming. Not surprisingly, this resulted in nonlinear gamma tracking when measuring with standard window patterns. Window patterns place the patch of colour or brightness to be measured in the middle of the screen, surrounded by black. In this configuration, the Sony KDL-55HX853 was detecting the high amount of darkness in the picture and dimming the LEDs. Remember that because each pixel doesn’t have its own individual LED light (LCDs are not self-emitting, unlike Plasmas), something has to give, and the LED brightness can’t be adjusted for each individual pixel. Not surprisingly, gamma was flat if we measured with full screen patterns (or the APL patterns, which keep the overall brightness level of the screen consistent by placing all the patches on the screen at once and only swapping out the centre patch which is to be measured) from the excellent AVSHD test disc.
We re-ran the measurements with the [LED Dynamic Control] set to the less aggressive “Low” setting, and got flat gamma even with the windowed patterns. In the end, we still went with “Standard”. Although the gamma performance is less predictable, we found the deeper blacks to be worth the trade-off… perhaps it’s just all the extremely deep blacks we’ve been seeing with Plasma TVs lately (which also have sometimes unpredictable real-world gamma performance) which pushes us towards this option. In any case, it’s up to you to make an educated decision based on the information provided. Certainly, we didn’t feel that the images being put out by the KDL-55HX853 with the highest “Standard” setting were obviously unnatural, although we could occasionally see a slight darkening or lightening a split-second after a scene transition.
By default, the TV tracked gamma quite evenly at 2.2, which is a better setting for “everyday rooms” with some ambient light present. Hollywood has decided upon a gamma of 2.4 for studio mastering in a light-controlled (dark!) room, so we’re calibrating to this now. The Sony HX853 had no trouble hitting a fairly flat 2.4 with the [Gamma] setting at “-1″. There is a very, very minor dip upwards at the 10% stimulus measurement (indicating a slight loss of shadow details), which is the result of the LED Dimming control darkening the LEDs during dark programme material (and, apparently, overcompensating). However, this is minor and we have to congratulate the company on a well-engineered implementation of dimming in an edge-lit LED LCD television. Sure, it’s no Plasma, but we watched movies with this option enabled, and felt that the end effect is beneficial and fairly transparent.
Disappointingly, there is still no colour management system on the Sony Bravia KDL-55HX853. Green is a little off-hue, but the biggest problem with colour is with blue. It can’t be fully saturated, which we thought was likely to be a limitation of the panel and the LED light sources. However, we found that the 55HX853 can actually produce an over-saturated blue – what it can’t do is produce one that’s both saturated and correctly tinted. This is a shame, but overall, the colour performance is good.
|Post-calibration CIE chart with reference to HD Rec.709|
To add more pain to the slight issue with blue, this colour is also too dark, as evidenced by the colour luminance measurements. We did experiment with the [Live Colour] control in the hope that it would modify the colour in a way which would let us correct its over-cooked effects with the main [Colour] control, but we had no such luck. The above result, as always, is the best we could get out of the display, which is still fairly good. Blue does look a little anemic at times, though. It could have been better if the Japanese brand would join other manufacturers in adding colour hue, saturation and luminance controls. So, Sony – next year, right?
|Post-calibration colour luminance (coloured bars = targets; black bars = measured values)|
|Post-calibration colour saturation tracking|
The results we got from our new saturation tracking measurements were mostly linear in terms of hue: most of the hue errors were the same as we’d already seen with the standard gamut measurements; there were no huge surprises with, for example, reds turning pink at certain saturation levels. As we’re seeing with a lot of HDTVs, the colours appear to saturate a little too quickly, but this is going to be a nearly invisible quirk. The only thing to mention is that when measuring with windowed patterns and the [LED Dynamic Control] enabled, we got very high luminance errors, because, of course, the KDL-55HX853 was detecting the black border around the test window and dimming the lighting. This is basically unavoidable with LED LCD local dimming, unless you have a full backlight array that can only dim localised areas of the picture (and even on TVs which have this, the algorithm needs to be well-designed, too).
We attached a pair of Sony TDG-BR250 glasses (supplied for review purposes, but not with retail models) to the front of our Klein K-10 meter, and, making sure that no stray, unfiltered light was getting into the lens to contaminate the readings, we began assessment and calibration of the HX853′s 3D mode.
3D Mode Greyscale
Prior to calibration, the green tint of the Sony active-shutter 3D glasses we used with the KDL-55HX853 negatively affected the picture quality, with familiar memory colours (flesh tones being the most obvious example) being skewed towards olive. Typically for an LCD display, the error is fairly consistent, which bodes well for calibration:
|3D Pre-calibration RGB tracking and delta errors (dEs)|
The difference made by 3D calibration was huge on the Sony KDL-55HX853. There is absolutely no need to compromise greyscale or colour accuracy to give the impression of a brighter 3-dimensional image with this (or in our opinion, any) 3DTV. We managed to reduce nearly all errors to the point of invisibility, but unfortunately, as in 2D, the low-end controls were not fine enough to avoid discolouration in the near-black levels. Still, the end result was a gigantic improvement from the green-tinted image we’d had before.
|3D Post-calibration RGB tracking and dEs in [Cinema 1] mode|
3D Mode Colour
3D colour gamut performance is different from in 2D, but with slightly different errors:
|3D Post-calibration CIE chart with reference to HD Rec.709|
|3D Post-calibration colour luminance (coloured bars = targets; black bars = measured values)|
The main issue we ran into was with the luminance levels of the colours. Unfortunately, calibrating Greyscale on the KDL-55HX853 required us to reduce the [G-Gain] (which controls the amount of green in the greyscale mix at high brightness levels) by a large amount, and we found out that this had a direct knock-on effect in the luminance level of Green chroma, too. This is unfortunate; although Greyscale calibration has an indirect effect on colour, these controls shouldn’t directly interact with this part of picture performance. We attempted to recalibrate 3D Greyscale avoiding big adjustments to the [G-Gain] control, but there was no other way to get an accurate result.
And, since Sony has no Colour Management menu screen even on its higher-end models, we couldn’t turn the Green Luminance level back up. We had to accept this compromise; in the end we felt that slightly dulled greens were better than a green wash over the entire picture.
Benchmark Test Results
|Screen uniformity||Slight “jail bars” visible, common for edge-lit LED|
|Overscanning on HDMI||Off by default with 1080i/p (excellent!)|
|Blacker than black||Passed|
|Calibrated black level (black screen)||0 cd/m2 (LEDs turn off, see ANSI checkerboard for real world performance)|
|Calibrated black level (ANSI checkerboard)||0.07 cd/m2|
|Black level retention||Auto-dimming with black screen in all modes|
|Video mode deinterlacing||Effective jaggies reduction|
|Film mode deinterlacing||Passed 2-2 PAL and 3-2 NTSC tests|
|Viewing angle||Standard for PVA LCD, blacks lighten and colours wash out from sides|
|Motion resolution||1080 with [Motionflow]: “Clear”, “Clear Plus” or “Impulse”, small artefacts|
|Digital noise reduction||Optional, but see our notes to avoid bug with filter enabling|
|Sharpness||Excellent: Defeatable edge enhancement|
|Luma/Chroma bandwidth (2D Blu-ray)||Full Luma, Chroma horizontally blurred except in “Game” and “Graphics” modes|
|1080p/24 capability||No judder in 2D or 3D|
|Input lag||28ms compared to lag-free CRT|
|Full 4:4:4 reproduction (PC)||Yes, in “Game” and “Graphics” modes|
|Default [General] mode (2D)||56 watts|
|Default [General] mode (3D)||111 watts|
|Calibrated [Cinema 1] mode (2D)||56 watts|
|Calibrated [Cinema 1] mode (3D)||80 watts|
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