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REPORT

Sharpness and noise filter – less is more

The image sharpness also plays an important role when a flat screen television is being purchased. The contours of people and objects must be clearly recognisable and the image must not be displayed too softly, i.e. look too washed out. Here, it is an advantage if the image improvement options (especially sharpness and noise filter) can be deactivated or have a clear zero mark.

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Although in theory it is possible to draw a quantity out of the material being played back, in practice, the implementation is rather mediocre and often produces more negative aspects than improvements. Thus, an exaggerated or badly implemented "3D-NR", or noise reduction, which analyses several frames in succession causes strong trailing effects and an artificial "video look". Most simple sharpness functions often produce unpleasant double contours on a lower level ("Ringing"). Here, less is usually more.

No more prejudices: only scaling counts

The resolution of a flat screen television has almost become a religious war. There are two common errors:

1. A panel with a lower resolution is more suitable for playing back PAL SD material than one with a higher resolution (e.g. FullHD)

2. For Blu-ray, HD-DVD and HDTV, a FullHD panel is absolutely necessary; otherwise, the display quality will suffer greatly.

Where scaling is concerned, the resolution of the panel does not really matter. If the flat screen TV rounds the smaller image (e.g. DVD or PAL TV) up to the higher pixel count in an acceptable way, the resolution becomes irrelevant. This is not surprising, since generally what is known as oversampling is used: the image is then calculated to a considerably higher resolution to then be adjusted to the resolution of the flat screen TV in a second step (Downscaling).

When it comes to correct image processing, the wheat is separated from the chaff; this is generally the reason behind the considerably higher price of devices which are equal to those in the cheaper sector at first glance of the data sheet. TV manufacturers love to advertise with names which sound like they are of immensely high quality for their electronic goods. Just as one does not even nearly make a spring, "Faroudja und Co." do not automatically mean top image quality. It is the implementation and not the name on the chip used which decides the result.

You would be better advised to inform yourself in advance on the Internet about the quality of the integrated scaling technology, especially if you want to watch a lot of PAL television or conventional DVDs on your new LCD or plasma TV.

24, 50 and 60Hz, interlaced or deinterlaced: flexibility is everything

Users with the highest demands with regard to quality will not be able to do without a well configured video processor such as the iScan VP50, especially with large screens. With a price of over one thousand Euro, however, this investment is only worth it for true home cinema enthusiasts.

iScan VP50 video processor (Photo: iScan)

However, the following still applies: if you really value the perfect display of various image formats, you will need a flexible TV set. In the best case, it can be controlled pixel precisely and digitally via HDMI and supports as many frequencies as possible, ideally 24Hz, 50Hz and 60Hz. The manufacturers therefore often call such pixel precise control TrueScan. Our detailed article, "Perfect picture enjoyment: It all depends on the frame rate!" explains why it is important that various frequencies be supported.

Compared with scaling, the topic of "Deinterlacing" is often in the background. Unfairly, interlaced signals, or half frames, are more widespread. Our article, "Make 1 out of 2" Deinterlacing" examines this topic.

When buying a flat screen, a well-integrated deinterlacer is just as important as scaling, in any case as long as no additional video processor is in use. The aforementioned article explains what distinguishes good from bad deinterlacing and what aspects you should pay attention to.

Some TVs allow the recognition sensitivity of the deinterlacer to be adjusted so that film material can be recognised better. Fundamentally, statements such as "Reverse Pulldown" refer at least to the option of correct film mode in deinterlacing. At Samsung, this option is concealed behind "MoviePlus", but it is linked to inter-frame calculation without choice.

With some TVs, it is even possible on some TVs to be able to enjoy judder-free playback of 60Hz 3:2 signals where the film material is recognised correctly. The X3000 / X3500 range from Sony or the Kuro plasma TVs from Pioneer, for example, offer this functionality. Here, therefore, you are not dependent on 1080p24 output from the player, especially as this option does not apply for NTSC-DVD or a relevant broadcast in any case.

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