What the best Hz in TVs?

Hz or Hertz is a measure of frequency. It is used as a measure of all frequencies and not just those in television.

Televisions use several separate images every second to give the impression of a moving image. In North America, a full image is displayed 30 times each second, so it is described as a 30Hz signal. However, the signal is delivered in two parts, one after the other, hence the same signal is also described as 60Hz, with 60 "fields" being shown each second.


Some televisions boast 120Hz and even 240Hz operation. The signal delivered to the television is still 60Hz. The television takes the incoming signal and creates an intermediate image between each field. It does this by looking at the fields preceding and following the time of the intermediate field and then shows what it thinks would have been in the picture at that time. The idea is to provide a smoother picture with less flicker. Sometimes, the television does a good job of this conversion, sometimes it doesn't. It is vital to look at 120Hz and 240Hz televisions carefully to decide if the faster display rate actually improves the appearance of the image. Sometimes, it makes the image worse - hardly a good reason to invest more money into a television.


In Europe, the frame frequency is 25Hz (or 50Hz for field rate). Therefore, the high frequency televisions will operate at 100Hz or 200Hz. The principle of operation is identical to the 60Hz signals.


Regardless of some of the more outrageous claims by badly informed salesmen, broadcast signals are 60Hz or 50Hz. Broadcast signals are never higher than these rates and therefore, 100 or 120Hz televisions don't receive higher frequency signals than conventional televisions.


Finally, while talking of frequencies, the 60Hz field rate in North America and other NTSC regions in fact is not quite 60Hz. Due to technical limitations way back in the 1950s, NTSC color signals were broadacst at 59.94 fields per second or 29.97 frames per second. Although the technology no longer needs this somewhat odd frequency, the 59.94Hz standard remains in place to this day. Therefore, any broadcast signal claiming to be a 60Hz signal in fact will be 59.94Hz.