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Sony KDL40W4000 Calibration

by Vincent Teoh
21 May 2008

Greyscale

The Sony KDL40W4000 LCDBuy this for £734.66 at Dixons
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television comes with four [Colour Temperature] presets: "Cool", "Neutral", "Warm 1" and "Warm 2". In [Cinema] mode (from experience the one with the best gamma profile and most suitable for critical viewing), [Colour Temperature] "Warm 2" yielded a CCT that was closest to the D65 standard:

Warm 2 CCT Warm 2 RGB tracking
[Colour Temp] "Warm 2" CCT "Warm 2" RGB tracking

However, the resultant image would be overly warm (average CCT of 6000K) given the predominance of red. Unlike the W3000, regrettably the Sony KDL40W4000Buy this for £734.66 at Dixons
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does not offer white balance controls in its user menu. Feeling adventurous, we decided to break into the service menu to see if there existed options that could help us attenuate the red and calibrate the greyscale.

Service menu White balance
Service menu White balance

Although we managed to access the correct page within the service menu, we weren't able to make any adjustments to the individual RGB values. Not having the luxury of a service manual, all we could do was to set [Select level] between 0 and 4, each of which would summon pre-set values for RGB. Those of you who are well-versed with HDTV calibration will also have noticed the lack of separate cut and gain controls which normally allow for more precise calibration of the darker and lighter portions of the picture.

Note: Exploring the service menu without prior experience or the service manual at hand is a recipe for disaster. We so nearly committed a calamitous error within the service menu of the Sony KDL40W4000, but somehow managed to salvage the situation. You may not be as fortunate, so please refrain from accessing the service menu unless you have the proper instructions and know what you're doing.

Back to the user menu then. If "Warm 2" is too red for your tastes, you can opt for [Colour Temperature] "Warm 1":

Warm 1 CCT Warm 1 RGB tracking
[Colour Temp] "Warm 1" CCT "Warm 1" RGB tracking

Even though "Warm 1" strayed further from D65 than "Warm 2", the higher correlated colour temperature (CCT) of 7500K should be more tolerable than 6000K to most people for day-to-day viewing.

Colour

[Colour Space] "Wide" generated a green primary colour point that was oversaturated and tilted towards blue, and engaging [Live Colour] only served to extend the colour inaccuracies:

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

[Colour Space] "Standard" produced a colour gamut that was much more accurate... all three primary colour points (especially green which many HDTVs can't manage to get right) were almost spot on the high definition Rec. 709 specifications:

[Colour Space] Standard
[Colour Space] "Standard" CIE chart with reference to HD Rec. 709

Had we been able to calibrate greyscale to D65, secondary colour points would probably have been aligned more accurately, but as things stood, yellow and magenta were just slightly off. [Hue] control (which generally can be used to adjust secondary colours) on the Sony KDL40W4000Buy this for £734.66 at Dixons
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is disabled unless fed with an NTSC video signal.

Benchmark Test Results

Dead pixels None
Screen uniformity Clouding reducible to negligible levels
Overscanning on HDMI 0% with [Display Area] set to "Full Pixel"
Blacker than black Passed
Black level Excellent
Black level retention Stable if [Adv Contrast Enhancer] & [Light Sensor] off
Primary chromaticity Excellent with [Colour Space] "Standard"
Scaling Above average
Video mode deinterlacing Average; limited jaggies reduction
Film mode deinterlacing Failed 3:2/ 2:2 cadences in 480i/ 576i
Viewing angle Good for an LCD TV (90°)
Motion resolution 300
Digital noise reduction Acceptable at baseline
Sharpness Defeatable edge enhancement
1080p/24 capability (PS3) Accepts 1080p/24 video signal; no telecine judder
Input lag 30ms faster than Samsung F96

Black Level

Calibrated black level on the Sony KDL40W4000Buy this for £734.66 at Dixons
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LCD HDTV measured an excellent 0.05 cd/m2, i.e. slightly better than the W3000 series, and on par with the Panasonic PX80/ PZ85 plasmas. To sweeten matters even more, the auto-dimming which plagued the W3000 seemed to have been eradicated on the Sony KDL40W4000... as long as [Adv. Contrast Enhancer] and [Light Sensor] were not engaged.

One quirk of the Sony KDL40W4000Buy this for £734.66 at Dixons
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is that the LCD HDTV would default to a [Backlight] value of 5 when switched on had it not been allowed to go into "true" standby mode. Confused? Let us explain.

The Sony KDL40W4000Buy this for £734.66 at Dixons
Use code 'SALE25' for 2.5% discount
Then code 'DELTV' for free delivery
seems to feature 2 standby modes: "temporary" and "true". When you press the [On/ Off] button on the remote control to switch off the KDL40W4000, the LCD television will first go into "temporary" standby. After some time, you will hear a click indicating that the TV has gone into "true" standby. Activating [Quick Start] in the [Features] submenu will prolong the "temporary" standby period to around 2 hours.

If the Sony KDL40W4000Buy this for £734.66 at Dixons
Use code 'SALE25' for 2.5% discount
Then code 'DELTV' for free delivery
was switched on from "temporary" standby, the initial backlight would default to a value of 5 (even though it would still state the original value in the user menu). To test this on your own W4000, first set [Backlight] to "Min" then put the LCD television into standby. Now power it on, and increase [Backlight] to "1". Normally you would expect the screen to get brighter, but on our KDL40W4000 review sample it actually became darker. Ideally you should perform these steps in low ambient light with a static image on screen in order to detect even the smallest changes.

The solution is to allow the Sony KDL40W4000Buy this for £734.66 at Dixons
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enough time to "click" into "true" standby, because only then would the [Backlight] setting be saved. It stands to reason that [Quick Start] mode should not be activated, as the LCD HDTV would take much longer to go into "true" standby. Here's another tip... if you don't hear a loud "click" when switching on the KDL40W4000, it's very likely that the television never went into "true" standby, and you'd have to manually adjust the backlight to what it was before.

Note: Many thanks to Mr Paul Darrington who confirmed/ shared these findings and proposed the solution.

Screen/ Backlight Uniformity

Initially some clouding/ mura could be seen with the default factory settings, but proper calibration reduced this notorious uniformity problem to negliglble levels on the Sony KDL40W4000. Nitpickers might notice the slightest hint of backlight bleed at the top left corner, and lightness at the sides of the screen, but then again we haven't seen any LCD televisions above the size of 40" that could match the generally perfect screen uniformity of plasma TVs.

Static Resolution

With [Display Area] set to "Full Pixel" to achieve 1:1 pixel mapping with zero overscan, the Sony KDL40W4000Buy this for £734.66 at Dixons
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LCD TV successfully resolved every horizontal and vertical single-pixel-wide lines of a 1920x1080 HDMI source. However, over component the KDL40W4000 exhibited a lot of noisy interference when trying to display the 1920 vertical single-pixel lines. While real-world viewing material usually does not stress the television as much, it is advisable to choose HDMI connections over component whenever possible for better bandwidth availability.

Motion Resolution

Using Chapter 31 of the "FPD Benchmark Software For Professional" as our test pattern of choice, the Sony KDL40W4000Buy this for £734.66 at Dixons
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recorded a motion resolution of 300, which is what we'd expect from an LCD television not equipped with motion-compensated frame interpolation (MCFI) technology such as Motionflow 100Hz.

Video Processing

The Sony KDL40W4000 utilises Bravia Engine 2 video processing as distinct from the Bravia Engine EX found on the W3000 or Bravia Engine Pro on the X3000/ X3500.

Compared to the W3000, video mode deinterlacing on the Sony KDL40W4000Buy this for £734.66 at Dixons
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remained roughly the same (i.e. average, with limited smoothening of jagged edges). Scaling/ upconversion quality was improved, providing good detail with minimal ringing. On the other hand, film mode deinterlacing took a hit: the KDL40W4000 failed to detect 2:2 cadence over 576i and 3:2 cadence over 480i even with [Film Mode] set to "Auto". It did manage to deinterlace 1080i film-based content if [Film Mode] was engaged.

Digital noise reduction was acceptable at baseline, although motion smearing could be seen with some of the higher [Noise Reduction] settings. [MPEG Noise Reduction] did not blur as much detail as some other HDTVs' implementations do. We left both these noise reduction controls off most of the time.

Back to: KDL40W4000 Review

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