There is much talk these days about the frame rates in the new HDTVs. The frame rate is simply the number of different pictures of a TV screen can display in a second, and is also known as an indicator or set of "Hertz". Hertz is the scientific unit for cycles per second and is abbreviated "Hz". The latest buzzword is "120 Hz", a display of 120 frames per second. This is twice as fast as most of HDTV (60Hz) that are capable of, so it should look beautiful at the moving pictures.But the human eye can only process should be about 20 to 25 different images per second, which is why it does not matter what the framerate, as long as it is quicker than the eye can see?
The answer comes when you know that is not shot any video with the same speed. Movies are usually filmed at a rate of 24 Hz, which is filmed on television, the most at 30 Hz, and some sporting events are now filmed at 60 Hz.
Some simple math will show the problem, and cover the solution. When a TV set willDisplay with 60 frames per second, and the cable-television companies, he sends 30 frames per second, which is easily met: the TV shows each frame twice in a row, making an image of two consecutive frames. Each image is exactly 1/30th of a second on the screen recently, and things will look completely smooth.
So what happens if your DVD player sends 24 frames per second to the TV, but the TV will still show up to 60 on the screen? This is a little slower thanthe cable TV frame rate, so wait, if it simply shows each frame twice, and then the next, it will be a gap between black and the movie looks terrible. So the TV has a frame triple, double the next, three times the following, and so on, there is show a total of 60 frames per second. This is known as 3:2 pulldown.
The 3:2 pulldown trick works OK, but it is a problem. A picture takes 20th a second, then take the next 30th book. A 20 oneSeconds is enough for most people to say that it is really a static image, and when the camera pans around a scene, it seems to move differently. But if your TV is capable of 120 frames per second display, it can take the 24 Hz input and simply show each frame 5 times in a row for a total of 1 / 24 (or 5 / 120) seconds per frame without variation from image to image. And if video is 30Hz, it displays each image 4 times in a row for a total of 1 / 30 (or 4 / 120) per secondFrame. Problem solved.
Now that frame rates are fast enough to keep any kind of input properly, HDTVs not only a high resolution in X and Y (width and height display) dimensions, but also in the t (time) dimension. As in all types of digital media means a higher resolution, smaller units of data, and that natural reproduction does the reality. The 120 Hz frame rate is not very common, until 2008, but some have already HDTVs, such as the Sony Bravia XBR4Series and the Sharp Aquos 92U-series.
HDTV has certainly) in the fourth dimension (time, but has skipped the third (depth) in the process. Until we begin to see holographic films on DVD, we have to wait for a real four-dimensional TV.
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