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Technology On Philips 42PF9831D


Ambilight Full Surround

This is the only Philips model to have the Ambilight technology at 4 sides, reflecting off the pearl white border, giving it an ethereal presence. The Ambilight, coupled with the unique styling has a dramatic presence and has drawn the approval from our female friends. The idea is that by illuminating the sides of the panel with the same hue from the nearest pixel, the technology can help to reduce eyestrain and improve blacks, detail and colour.

We were certainly skeptical over the claims, especially when SMPTE recommendations were to use 6500K backlighting at only 10 percent of intensity of the brightest white of the screen. So, with these reservations we gave the Ambilight a 2 week trial. The Ambilight has four settings :relaxed, moderate, dynamic and colour. We chose relaxed the majority of the time with a low brightness setting and this seems to be very conducive for casual viewing at low light conditions.. The moderate and dynamic settings caused the ambilight to change colours too quickly and this was annoying after a while. The colour setting allows the user alter the various aspects of the Ambilight from the original presets. Ambilight does not work in bright daylight.

To be fair, the technology did work to reduce eyestrain and so this will be useful in bright LCD’s watched in low light conditions. The black level was very marginally improved, but not enough for me to recommend it strongly. In summary, it’s a feature I wouldn’t mind having but it is something I wouldn’t miss.

Pixel Plus 3 HD

Definitely works on SD material, especially when the source is really poor. It introduces edge enhancement (sharpening) with clear haloing effects but for poor SD source, its not a problem to me. There are some minor adjustments of contrast when it is on and the picture will appear more stable, but I can't see the any other benefits. (doesn’t mean its not there). I tend to leave it off in HD mode, as the picture will not need any enhancement in general. The bottom line is that I prefer the picture quality of Pixel Plus 3 HD in Standard Definition material.

ClearLCD with Aptura Backlighting

Motion blur in LCDs is caused by a combination of slow reacting crystals (high response time) and the `sample and hold' effect (images persist on the screen for the frame duration due to constant backlighting). Clear LCD combines response time correction strategy (overdrive) and a scanning Aptura backlight to `blank' out the image, thus reducing motion smearing. The reduction in screen brightness from the scanning backlight is solved by using hot cathode fluorescent lamps capable of greater light output. The ClearLCD feature is not available in HD mode.

Dynamic Contrast

Leave it off! The contrast of the display kept on changing on long pans when it is on and this is especially noticeable in football or rugby games. The green colour of the field kept changing colour for an example and there was a noticeable flicker when the contrast is adjusted.

Digital Natural Motion

Designed to reduce judder and motion smearing by presumably and create smoother motion via frame rate interpolation. All it did was to create an artificial pseudo fast forward picture on 24 fps material. My eyes could not adjust to this although I have heard some users saying that the side effect does wear off after a while. Not recommended in my opinion.

MPEG Noise Reduction/Digital Noise Reduction

Excessive digital noise reduction cleans up noise but also reduces detail by blurring. Choose a setting that gives you some balance. MPEG noise reduction could not eliminate mosquito noise around rugby players, but I just leave it on all the same. This is really an issue on poor SD material with a lot of action in it. My suggestion, get a HD upgrade and you won’t have to deal with this.

Colour Enhancement

Colours look more saturated as you go up the 4 settings. I try to calibrate TVs for better colour accuracy and so any `enhancement’ function is generally useless to me. If you don’t like calibration, colour adjustment this way can give a perceived better quality. Just be aware that it may not be accurate.

Active Control

Changes many of the above controls on the fly, but not recommended if you want picture stability.

Back To: 42PF9831D Review

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