Introduction

A standard PAL television will refresh the picture at a frequency of 50Hz or 50 Frames Per Second (FPS). The Frames Per Second are the number of frames needed to create the illusion of movement. On a 50Hz Cathode Ray Television (CRT), because the picture was produced by an electron scan, there was a visible flicker that could be detected by the human eye.

Our eyes are at times are sensitive to this frequency depending on the speed of the image, the level of darkness, and the level of brightness so you will sometimes notice the picture flicker on a 50Hz TV. Also the larger the screen is the more noticeable the flicker is.

Early 100 hertz technology

Originally 100hz (100 FPS) televisions operated at double the Frames Per Second by creating a duplicate of each frame and inserting it after the original one. By doubling the frequency of the scan to 100Hz and inserting a replica frame this effect was eliminated as far the human eye perceives it. The effect of this is to significantly reduce the flicker.

Does 100hz improve the picture on 100hz Plasma and LCD televisions ?

LCD and Plasma televisions dont produce flickering because they don’t produce the picture with an electron scan. However LCD TV’s still benefit from 100Hz because advanced digital circuitry creates an extra frame or middle image. This is done by the TV inventing an extra frame using complex interpolation and motion compensation calculations to work out what the extra fields and frames look like rather than inserting a replica frame. (e.g. the second frame is not the same as the first frame).

Nevertheless even at 100 Frames Per Second the picture still does not show an absolutely smooth picture especially with fast moving images. Several television producers attempt to reduce this further by using advanced digital picture processing. Typically there is still a little blurring on quick moving images although the benefits are sharper pictures, clearer and better defined surfaces, and smoother movement than is possible from 50 FPS LCD and Plasma TVs.

e.g. For a football that travels ten pixels from left to right between frames one, two and three, the 100 hertz TV will digitally create two further frames between one and two, and two and three, between which the ball will move five pixels. This will result in five frames where the football moves a total of ten pixels i.e. the original frames one, two and three plus the digitally created frames inserted between one and two, and in between two and three. The result of this is that the eye sees an image that moves smoother than before.

The benefits of 100 Hz

100Hz televisions have a clear benefit of eliminating the majority of ghosting effects now and then seen in LCD TVs. The ghosting effect caused by the next image being shown before the previous one has faded away. Plasma television also benefits from 100hz because the extra middle frame smoothes motion on the screen

Manufacturers such as JVC, Panasonic, Samsung, Toshiba, LG, Sony, Philips, Hitachi and Pioneer have got 100 hertz Plasma and LCD televisions.

200hz the next generation

A new series of 200 hertz televisions have been launched by Sony which digitally inserts three additional frames between the original 50 hertz frames. Thus fast moving sequences are delivered with a smoother, more fluid and sharper picture than 50Hz or even 100 hertz TV’s.

The added benefit for people with photosensitive epilepsy

Research has proven that 100 hertz televisions can assist in preventing seizures in people who suffer with photosensitive epilepsies when viewing television or playing computer games.

Armadeus Cornelius is an Home Entertainment enthusiast and expert with nearly 2 decades experience in consumer electronics. His website at www.digitaldirect.co.uk offers 100Hz and 200Hz TVs and a large selection of AV products at rock bottom prices. For your convenience look at these 100 Hertz Full HD LCD and 100Hz Philips TV

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