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Sony KDL40X3500 Measurements

by Vincent Teoh
6 November 2007

Pre-Calibration

The [Theatre] key on the remote, which according to the manual will "automatically set the optimum picture and audio quality for film-based content", in practice calls up the [Cinema] mode. True to form, this – with [Colour Temperature] left at its default "Warm 2" – provided the correlated colour temperature (CCT) closest to 6500k:

Warm 2 CCT Warm 2 RGB Tracking
[Colour Temperature] "Warm 2" CCT
"Warm 2" RGB Tracking

Although there existed a slight predominance of red, this nevertheless represented one of the best greyscale tracking I've seen out-of-the-box... certainly the best on an LCD TV.

On the colour front, measurements were equally impressive. The default values in [Cinema] mode resulted in a slightly undersaturated picture, but all the primary and secondary colour points did not deviate too much in hue. Setting [Colour Space] to "Wide" would cause green to adopt more blue and oversaturate. These errors would progressively worsen when I went through [Live Colour] from "Low" to "High":

Wide Colour Space High Live Colour
[Colour Space] "Wide"
[Live Colour] "High"

Greyscale & Colour Calibration

Using the RGB cut and gain controls in the [White Balance] submenu, it was possible to calibrate greyscale to less than four dEs (delta errors) from 20% luminance onwards, an excellent result by anyone's standards:

Post-calibration CCT Post-Calibration RGB Tracking
Post-Calibration CCT
Post-Calibration RGB Tracking

Even though Sony KDL40X3500 did not sport any full-featured colour management system, nor support hue/ tint control over non-NTSC material, the colour points fell into place (with reference to high-definition Rec. 709 standard) once I got the greyscale right, and nudged the [Colour] value up:

Post-calibration CIE with reference to Rec. 709

Benchmarking

Dead/ stuck pixels 0
Screen/ backlight uniformity Mild clouding reducible to negligible levels
Overscan 0% with [Display Area] set to "Full Pixel" (1080 source) or "+1" (only 720p on HDMI); and "Full 1" & "Full 2" (VGA)
Blacker than black Passed
Black level As good as Pioneer PDP4280XD when auto-dimmed
Black level retention Stable if [Game/ Text Mode] is "On".
Colour chromaticities Excellent
Scaling Average
Video mode deinterlacing Slightly above average with [DRC Clarity] set to "100"
Film deinterlacing ([Film Mode] on) Quick 3:2/2:2 detection, but loses the lock intermittently
Viewing angle 120°
Motion resolution 550 with [Motion Enhancer] on; 300 when off
Digital noise reduction Very effective, but introduces motion trails
Sharpness Defeatable edge enhancement
1080p/24 capability (PS3) Accepts 1080p/24 signal from PS3 – no telecine judder
1:1 pixel mapping Yes, when [Display Area] is set to "Full Pixel"

Black Level

Let's do a "good news/ bad news" routine. The good news is that the absolute lowest black level measured on the Sony KDL40X3500 was lower than that on the KDL40W3000, and – to my surprise – even rivalled that on the Pioneer Kuro PDP-4280XD. This may explain the higher contrast ratio on the X3500/ X3000 series compared to the W3000.

The bad news is that this could only be achieved through auto-dimming when the screen is black or near-black, and NOT through any settings in the user menu. Just to experiment, I tried adjusting [Backlight] to "Min", [Contrast] to "Min", [Brightness] to "Min", and [Power Saving] to "High" to make sure I was getting the lowest possible black luminance from the user menu: the end result was still higher than the black level furnished by auto-dimming.

As a consequence, the black level fluctuates on the Sony KDL40X3500 especially when the screen is black. This was more noticeable than on the W3000 series, because there is a bigger difference between the lowest absolute black level (achieved through auto dimming) and calibrated black level (achieved through user menu adjustments).

There is a method however to disable auto-dimming on the Sony KDL40X3500 from the user menu (thanks to Sam Hawker for the heads up). By engaging [Game/Text Mode], calibrated blacks stabilised to around the level of a Samsung F86, which is of course still excellent for an LCD television and so is the least of our problems. My main bugbear with this approach is the unwelcome forfeiture of some video processing functions, the most valuable of which being Motionflow 100Hz, the chief selling point of the X3000/ X3500 series.

Screen/ Backlight Uniformity

Those of you who have followed the history of Bravia 1080p LCD panels will know that this auto-dimming is Sony's response to the clouding problem (the mura effect is most obvious on blank input with a high backlight setting in low ambient light condition) that has plagued the W2000 and to a lesser extent the X2000 series.

With or without the help of auto-dimming, quality control on the latest batches of Sony LCD televisions appears to be much better: my Sony KDL40X3500 review unit did not exhibit as much clouding as on the KDL40W2000 that I tested seven months ago even with backlight cranked to maximum. Calibration reduced the clouding to unobtrusive levels; probably only the nitpickers would notice the slightest hint of backlight bleed at the top right corner, and lightness at the sides of the screen. If you demand perfect screen uniformity at this size or larger, your best bet would be to go with a plasma television (which, of course, has its own issues).

Static Resolution

With [Display Area] set to "Full Pixel" and all the unnecessary edge enhancement controls – [Sharpness], [DRC Mode], [Edge Enhancer] and [Detail Enhancer] – turned off, the Sony KDL40X3500 fully resolved the single-pixel horizontal (1080) and vertical (1920) lines over HDMI and component. Whereas the KDL40W3000 exhibited some interference on this test pattern over the component input, on the KDL40X3500 the component result was as clean as HDMI's, indicating better bandwidth availability.

Motion Resolution

With [Motion Enhancer] engaged, the Sony KDL40X3500 maintained all 4 separate lines at a resolution of 550 when the test pattern from Chapter 31 of "FPD Benchmark Software For Professional" started scrolling horizontally at a speed of 6.5 ppf. There was no significant difference in motion resolution between the "Standard" and "High" settings, but it did drop to 300 when I switched [Motion Enhancer] "Off".

A similar result was obtained by Gary Merson, the US HDTV analyst who brought this test disc to my attention, when he reviewed the Sony XBR4 (US version of X3500). Although a motion resolution of 550 is still inferior compared to that regularly achieved by plasmas, I haven't seen any LCD television do better thus far.

Video Processing

Initially I concluded that the Bravia Pro engine on Sony KDL40X3500 offered nothing extra over the Bravia EX found on the KDL40W3000, because for the life of me I couldn't see any difference when I ran my battery of video processing tests: scaling and video deinterlacing for standard-definition material remained average; and the occasional loss of 3:2/ 2:2 lock persisted.

The answer lay in the [DRC Mode] which produced more perceptible advantages on Sony KDL40X3500 than the W3000 particularly for SD content. You can finetune it further using [DRC Palette] to maximise the benefits while keeping unpleasant artifacts to a minimum:

DRC Palette

[Reality] sharpened the detail in images, but unfortunately also introduced inevitable ringing and unnatural edge enhancement, so I recommend setting it no higher than 20 for standard definition viewing (for HD [DRC Mode] should not be engaged anyway). [Clarity] was much more useful – it smoothed the jaggies especially in the directional filtering test pattern that the Sony KDL40X3500 would have failed outright if [DRC Mode] was left off. And the best part is there wasn't any noticeable ill effects even when [Clarity] was set to the maximum value of "100".

[DRC Mode] should never be engaged when watching movies: it caused the KDL40X3500 to lose its 3:2/ 2:2 pulldown lock on relevant film material more frequently.

The Sony KDL40X3500 performed just like the W3000 in the areas of mixed edit detection, noise reduction and 1080p/24 handling, so please refer to the relevant section in the Sony KDL40W3000 review if you need further details.


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