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Pioneer PDP4280XD Calibration & Test

by Vincent Teoh
15 July 2007
TLC Broadcast

Baseline CCT (Correlated Colour Temperature)

The default picture preset for Pioneer PDP4280XDBuy this for £1139.99 at Dixons
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is [Standard] out of the box, which while not as blinding as the [Dynamic] mode, was still too blue for me. As expected, the [Movie] preset yielded a greyscale tracking closest to D65 pre-calibration:

Pre-calibration CCT in [Movie] mode Pre-calibration RGB tracking in [Movie] mode
Pre-calibration [Movie] mode CCT
Pre-calibration [Movie] RGB tracking

The slight red predominance gave the PDP4280XD a colour temperature between 6250k and 6500k from 20% stimulus upwards, which is outstanding compared to the baseline CCTs of other HDTVs I've tested recently. There was definitely room for improvement though, as dEs were above 4 throughout, and the top-end luminance was clipping. Since Pioneer had been generous enough to include white balance controls in the user menu, gleefully I made use of them to calibrate the greyscale.

Greyscale Calibration

To take advantage of the independent input memory settings, I started off my calibration in the [User] mode. Within 10 runs I obtained the following greyscale with dEs of less than 2.5 from 30% stimulus onwards:

Calibrated [User] CCT Calibrated [User] RGB Tracking
Calibrated [User] mode CCT
Calibrated [User] RGB tracking

But a quick glance at the resultant gamma curve unearthed something disturbing:

Calibrated [User] Gamma Calibrated [User] Gamma Tracking
Calibrated [User] mode gamma
Calibrated [User] gamma tracking

I've covered this in my Samsung LE40M86BD review, but what the above 2 graphs show is that the Pioneer PDP4280XDBuy this for £1139.99 at Dixons
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(calibrated in [User] mode) exhibited skewed gamma tracking: the picture becomes darker than it should be as the input signal level reduces in intensity, which will have an adverse effect on shadow detail.

To further complicate matters, I discovered that each of the [PureCinema] modes – "Off", "Standard", "Smooth" and "Advanced" – generated a difference in peak brightness, in some cases as drastic as 15 cd/m2. Why Pioneer let some deinterlacing functions influence peak brightness we will never know, but the implication is clear: before starting your calibration, make sure you select the [PureCinema] mode you're most likely to use for that particular input.

I experimented with all the options in [User] mode but the skewed gamma tracking just couldn't be ironed out. Frustrated, I discarded all the hard work I have done so far, and recalibrated the Pioneer PDP4280XDBuy this for £1139.99 at Dixons
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from scratch. This time though I chose to do it in the [Movie] mode... from experience some manufacturers implement different gamma profile for each individual presets. Here's what happened:

Calibrated [Movie] mode CCT Calibrated [Movie] mode RGB tracking
Calibrated [Movie] mode CCT
Calibrated [Movie] RGB tracking

Calibrated [Movie] Gamma Calibrated [Movie] Gamma Tracking
Calibrated [Movie] mode gamma
Calibrated [Movie] gamma tracking

Jackpot. Gamma tracking is now supremely flat at 2.25 between 20% and 100% stimulus, but the dip between 0% and 20% persists, meaning that some shadow detail will inevitably be suppressed. If you really want to squeeze more shadow detail out of the picture while maintaining video black, you could increase [Gamma] to 3 and set [DRE Picture] to "Mid", but this will entail a sacrifice in image contrast.

Baseline Colour Chromaticity

Colour Space 1 Colour Space 2
Baseline [Colour Space] 1 Baseline [Colour Space] 2

The manual suggests that [Colour Space] 1 on the Pioneer PDP4280XDBuy this for £1139.99 at Dixons
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is optimised for a more vibrant colour reproduction: indeed the colours were somewhat over-saturated when plotted against REC 709 (reference for high-definition colours) on a CIE chart. The default [Colour] value of -6 in [Movie] mode led to an undersaturated gamut for [Colour Space] 2, but one would expect to correct this easily by bumping [Colour] up a few notches and then mapping the primary and secondary colour points to REC 709 using Pioneer PDP4280XD's colour management system.

Colour Calibration

Talk about making the wrong choice when faced with a 50-50 decision. I went with [Colour Space] 2, thinking that it's more likely to conform to standard colour gamut... after all even the manual describes it as "standard colour reproduction".

Calibrated [Colour Space] 2
Calibrated [Colour Space] 2 CIE chart with reference to REC 709

Looks promising: all the colour points on the spot, with the intersecting lines converging on D65. Surely this is it?

Sadly, even after calibration [Colour Space] 2 actually threw up some disconcerting colour decoder inconsistencies, and 0% to 75% saturation depletion. Because the [Colour] control on Pioneer PDP4280XDBuy this for £1139.99 at Dixons
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affects both colour saturation and intensity in uncertain proportions, it was not possible to fix one without spoiling the other. [Tint] and [Colour Management] mainly alter hue and so were of no use in my attempts to rectify the saturation/ intensity errors.

Note: Colour decoding error cannot be gleaned from a CIE chart. It is generally detected through real-life material, filters or less commonly, colour intensity measurement.

Up against a brick wall yet again, I abandoned [Colour Space] 2 and plumped for [Colour Space] 1 to calibrate the colours from the ground up:

Calibrated [Colour Space] 1
Calibrated [Colour Space] 1 CIE chart with reference to REC 709

On surface this looks worse than the chart for [Colour Space] 2, as the red, green, yellow and cyan colour points are mildly oversaturated. However, the colour decoder and 0% to 75% saturation aberrations that I encountered in [Colour Space] 2 are now totally gone, making [Colour Space] 1 the undisputed gamut of choice. One for the pub quiz?

Clarification 19 July 2007: The above only applies to HD (REC 709); for SD content you should still use [Colour Space] 2.

Benchmark Test Results

Dead pixels None
Screen uniformity Perfect*
Overscanning on HDMI, Component 2.5 percent (0% in [PC] mode)
Blacker than black Passed
Black level Best I've ever seen/ tested
Black level retention Stable
Primary chromaticity Excellent
Scaling Good
Video mode deinterlacing Excellent
Film mode deinterlacing Competent 3:2/ 2:2 cadence detection
Viewing angle Excellent (> 160°)
Motion blur Normal for plasmas
Digital noise Some settings may cause increased PWM noise
Sharpness Defeatable edge enhancement
Image retention None
Posterization Effectively none
1080p/24 capability (PS3) Accepts 24fps; no telecine judder

Screen Uniformity*

Pioneer PDP4280XDBuy this for £1139.99 at Dixons
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's predecessor, the PDP4270XD, suffered from what was known as the "dirty screen effect", where fixed irregularities manifested on screen during panning camera shots over a uniform pastel/ near-grey background. From two feet away, the screen on the Pioneer PDP4280XDBuy this for £1139.99 at Dixons
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looked blemishless... though if you look hard enough with your nose up against the glass, you may be able to catch a trace of distortion from certain angles in areas where light is reflected. Don't worry, I'm just nitpicking – you won't see this from your normal sitting distance.

Overscan

When fed with supported resolutions, you can achieve zero overscan in the [PC] mode over VGA (after "Auto Adjust") and HDMI, but because white balance controls, film deinterlacing and colour management system are disabled in this mode, I'd avoid it at all costs.

Black Level & Contrast Ratio

The hype surrounding Pioneer's eighth-generation plasmas' revolutionary black level is fully justified. The Pioneer PDP4280XDBuy this for £1139.99 at Dixons
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is HDTVTest's current black-level champion*, clocking in a minimum luminance that is more than 100% lower than that measured on our previous holder, the Panasonic TH42PH9. As a result, dynamic contrast ratio on the PDP4280XD also skyrocketed to a new record in excess of 3,000:1*.

*Update 16 August 2007: Since the publication of this review, I've tested its bigger brother Pioneer PDP508XD which has an even lower black level (although not by much) and hence a higher contrast ratio.

Video Processing

The Pioneer PDP4270XD's video processing was exemplary, and I'm pleased to say that the PDP4280XD largely continues this fine tradition. For the purpose of this review, I'm going to break them down one by one... there's just so much to talk about.

Scaling

Scaling quality on the PDP4280XD was just a smidgen behind the Panasonic TH42PH9, which translates to "good" compared to the rest of the field.

Video Mode Deinterlacing

Similar to its predecessor, the Pioneer PDP4280XDBuy this for £1139.99 at Dixons
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excelled in this department, effortlessly passing the rotating wheel, bouncing bars and waving flag test patterns with flying colours thanks to its motion adaptive and directional filtering.

Film Mode Deinterlacing

The Pioneer PDP4280XDBuy this for £1139.99 at Dixons
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offers three modes located under the [PureCinema] submenu that you can engage to process film content: "Standard", "Smooth" and "Advance". All 3 modes detected and processed 3:2 and 2:2 cadence competently, but there was a slight hiccup in 480i/60 and 1080i/60 over both component and HDMI.

For reasons I don't understand, not only was the PDP4280XD sluggish in locking onto 3:2 cadence when presented in such resolution/ frequency, it had difficulty maintaining the lock – the PDP4280XD drifted in and out of film mode deinterlacing, causing intermittent moire on the racing track test scene. I tried various combinations including [Drive Mode] and [I/P Mode] but did not manage to resolve this.

To be honest I don't think it's that big of a problem... if you know what jaggies, twitter and moire look like, you probably own a player that deinterlaces film content capably anyway, so you can simply let your player do the job by sending a progressive signal to the plasma.

"Smooth" mode combines film mode deinterlacing with an element of motion compensated frame interpolation. From my tests, motion blur during slow pans was reduced considerably, but there remained the odd shimmer around moving objects... only you yourself can decide whether this trade-off is worth it.

In "Advance" mode, the original 24 fps film frames are reconstructed then displayed at 72 Hz, in the process eliminating the infamous telecine judder. Use this mode to watch your NTSC and HD/ Blu-ray films for a smoother experience.

Common Plasma Problems

  • Posterization: the least I have seen on a plasma (effectively none).
  • Image retention: none, even though I switched off the [Orbiter] function from the start.
  • Phosphor trail: a.k.a. "green fringe", "yellow smear" or "plainbow". It was still present on the Pioneer PDP4280XDBuy this for £1139.99 at Dixons
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    , but less obvious than on my Panasonic TH42PH9 which has done more hours (the luminosity of the phosphors decreases with use).
  • PWM Noise: sit close enough to any plasma screen and you'll see shimmering pixels caused by pulse-width modulation (the way plasmas are powered). Certain settings on the PDP4280XD had been found to increase PWM noise, for example [Energy Save] "Mode2" under all circumstances; and the combination of [Drive Mode] "2" and all the [PureCinema] modes (except "Smooth") when fed with a 50Hz (PAL) signal.

    Common to these settings was an overall reduction in the power supplied to the plasma panel. How did I know? Plasma buzzing (another power-driven phenomenon) decreased considerably when these settings were selected... the increase in PWM noise probably stemmed from insufficient sub-field drive voltage.

    [Energy Save] "Mode2" is not an issue... just don't use it. As far as I can see, the only real problem comes when you are watching PAL video content such as sports – [Drive Mode] "2" is pretty much necessary to avoid judder. Here you have to make a choice: either put up with some judder by using [Drive Mode] "1", or accept a judder-free but noiser picture with [Drive Mode] "2". Nothing's perfect in life.

Back To: PDP4280XD Review

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