What does Hertz mean for HDTV?

Question

I keep reading about frames and refreshing and stuff and I'm confused. If HD is so great how come it has problems like this? Why do people pay thousands of dollars for skipping pictures? Doesn't that disrupt your viewing?

Answer 1

Hz for HDTVs usually is in reference to an LCD HDTV's refresh rate. This is how often/quickly its refreshing (re-drawing) the screen.



With fast moving motion, the "standard" of 60Hz is found to not hold up very well. Basically consumers found out at LCDs are inherently bad with fast moving images. They suffer from motion blur (ghost trails) at 60Hz. So that's when you started to get these TVs with 120Hz or 240Hz. This was the manufacturer's response to the problem. They artificially have the TV draw extra frames (either by double or interpolating) to mask the motion blur. But right now you have to pay a huge price premium for this.



This only occurs with LCDs. CRT, Plasma, and DLP all have near instantaneous response times. They do not suffer from motion blur at all. Sometimes their spec sheets list refresh rates, but that's just marketing, it really doesn't mean much. The technologies are inherently already great.



So the problem has nothing to do with HDTV, it only has to do with the technologies that playback HDTV. There is no motion blur or skipping of pictures on the raw original HD materials. Its purely only on playback on LCDs.



Also, TV size matters. The larger your TV the more likely you'll notice this. But below some sizes you might not see it at all, even with an LCD. Sets of 40" and higher, and moreso 50" and higher would definitely exhibit the motion blur problems with the standard 60Hz set. But sets of 37" and smaller, not so much, if at all. So you could actually get one of those at 60Hz and still have an amazing HD experience (on an LCD).

Answer 2

Plasma all the way-Only thing Plasma Starts at 42" and goes up -better and deeper blacks -wider off angle viewing -awesome for fast motion-600Hz refresh rate while the top LCDs/LEDs are only 240Hz-Best for gaming and sports watching with a LCD you will have to drop it to 60Hz for gaming to help eliminate the lag -No burn in-on new plasmas-was a problem 5 years ago -they do use more power than the LCDs-But really if you cant afford the possible 3-5 bucks a month in and increase in your power bill-You do not need to be buying a big tv to begin with. -The short life people are talking about equals about 10-15 years of watching. really who wont buy a new tv in 10 freaking years??? -I have my 65" Hung about 4' from a 72" window and even with the blinds open i have no trouble seeing it or get any annoying reflections. But The ceiling light that is behind the couch will reflect off it at night. Right now the top Plasmas are made by Panasonic(according to Cnet, consumer reports and a few home video mags). Right now 50" 1080p ( i own this one and the 65" version) at best buy USA around 899 for the 50" 720p is 599 LED tvs are just a LCD with a LED back light instead of Florissant tubes!!!!!!!!!! LED tvs ARE JUST LCD with different backlighting they still suffer all the drawbacks of LCD but are just brighter @Paul It doesnt matter what your eye can see in Hz. You will still get fast motion judder and pixelation due to the refresh rate in an LCD/LED Also for gaming you cant use the higher refresh rates on LCD/LEDs because the way the LCD does it is a process call interpolation(i believe i spelled that correctly) which is what creates even more lag on games

Answer 3

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RE:

What does Hertz mean for HDTV?

I keep reading about frames and refreshing and stuff and I'm confused. If HD is so great how come it has problems like this? Why do people pay thousands of dollars for skipping pictures? Doesn't that disrupt your viewing?

Answer 4

TV Guy is right. Television and most film in America is filmed at a rate of 60 frames per second. Hertz is a measure of cycles per second. Since LCDs operate by twisting crystals with electronic stimuli, they (the crystals) cannot refresh or reset fast enough for 60 frames per second, creating a blurring effect. 120Hz just means that the crystals refresh at a faster rate (typically) by entering a black frame in between the frames of motion picture.



As the frame rate gets higher, the more sales are created. Plasmas do not have this problem,as their changes of pixels are the speed of light, but the frame rate above 480Hz is totally superfluous.



So... go with the TV you think looks good. Asking tech q's cannot determine the best picture as different people see differently. Go with what looks good.

Answer 5

Hz has nothing to do with HD itself, but with display technology.

You see LCD TVs can't refresh fast enough, so at 60 Hz (the normal video playback rate) when there is lots of movement you see "ghosting".

So, LCD manufacturers decided to refresh the picture at 120 Hz, by interpolating frames (not skipping), and then it became a marketing war, with 240 Hz, and higher.

If you had a plasma, you had nothing to worry...., but now the plasma people are getting into this stupid game.

Answer 6

I do not believe that is true

Answer 7

Was wondering this as well