Why are 120Hz TVs better?

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PCunicorn

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I know why a 120Hz monitor is better then a 60Hz one, depending on the person you will notice smoother motion in games if your system is capable of getting 120 FPS. But why would you want a 120Hz TV? Movies are only 24 FPS, and most console games don't go above 30 FPS.
 
120hz TV"s aren't actually 120hz. They interpolate the frames to make 24fps feel like 120fps.


The way it works I believe is for 24 fps, the tv will insert 5 (or 4?) frames in between each frame of actual content. This is why gaming in 120hz mode is not recommended, since there's a lot of input lag.
 
TV's run @24hz if possible (Blu-Ray) or 50/60hz (depending on the region). The xxxhz refers to motion interpolation which can be turned on and off.
 
There are some televisions that do real 120 Hz at 1080p. These televisions support the HDMI 1.4b standard so it has enough bandwidth to display 3D content at 60 Hz, but video games on consoles will still only output at 60 Hz. However, a PC running on these televisions over HDMI will be able to choose 1920x1080 @ 120 Hz as a resolution if the graphic card also includes the HDMI 1.4b standard (current gen AMD cards do, not sure about NVIDIA cards).
DIYmaster said:
@hajalie24 That's total horse shit. How you figure 120hz = input lag again?
Click to expand...
TVs that are not real 120 Hz use this as marketing speak to advertise their frame interpolation methods to make content appear smoother. The TV has a processor that will insert frames based on the pixel state of the frame currently being displayed. Because the actual content is still only running at 30/60 Hz, this will add unnatural input lag. Video content will also visualize other side effects from this type of processing, such as the "soap opera" effect.
 
it's just a marketing gimmick. As Hajalie said, it's just interpolating the missing frames. It used to be (and may have changed recently) that all of the 120Hz TV's were only capable of accepting a 60Hz signal. IIRC, it CAN display a true 120Hz/fps... but without most input sources feeding the TV a 120Hz signal, it's sort of a waste. PC's obviously can but I think that's about it (and maybe next gen consoles). As was also said, it introduces input lag, as it has to do the processing before an image is displayed but on top of that, it can also produce artifacts. reticles, for example (from a FPS), display funny as some TV's can't accurately predict how they'll move... so the TV bugs out when trying to create the missing frame(s).

The one upside is that 60 isn't evenly divisible by 24 (which most movies run at) so it can lead to missing frames... but 120 is (5). So, technically, it can display a frame, 4 blank frames, and so on.... and it should look better (with interpolation turned off)
 
DIYmaster said:
@hajalie24 That's total horse shit. How you figure 120hz = input lag again?
Click to expand...

Not bullshit. It has to make the missing frames (a 60hz/fps input signal can't magically be turned into 120) by comparing the last frame, and the next frame, and creating an image that it 'thinks' would be correct.... so that takes processing time which = input lag


edit: and that of course goes out the window with true native 120hz... but anytime it's doing interpolating, which all 120hz TV's do to a 60hz signal, it's adding input lag
 
Most TV's have really high input lag, even with motion interpolation turned off. Sony's W6 & up series usually have low input lag and do not use LED PWM Dimming (Side Effects) while most LCD TV's use low PWM frequencies.

The Sony KDL42W705B (Review, 700B in North America) is my top pick for gaming.
 
PCunicorn said:
I know why a 120Hz monitor is better then a 60Hz one, depending on the person you will notice smoother motion in games if your system is capable of getting 120 FPS. But why would you want a 120Hz TV? Movies are only 24 FPS, and most console games don't go above 30 FPS.
Click to expand...

Because 120 is the first number that can be divided into both 24 and 30. Most film and video content displays at 24FPS, 30FPS or 60FPS. 120Hz allows 5 duplicate frames of 24FPS content or 4 duplicate frames of 30FPS content to be displayed.

Really it's 23.997, 29.997, etc. for technical reasons but it's just easier to talk about 24FPS. 30FPS and so on.
 
Ah yes, motion interpolation. On most HDTVs that I play on, I enable or disable 120Hz/240Hz Motion Interpolation depending on the amount of input lag present. If I'm playing a game where the input lag makes it unplayable, I stick the HDTV in Game Mode, which eliminates all/most extra processing, including motion interpolation. In other games where the input lag causes no issues, I like to leave it on because the extra fake frames makes the game appear as if it is running at a higher framerate. A 30 fps game would sort-of look like it's running at 60 fps. I rather enjoy this aspect of motion interpolation. Not using Game Mode also allows me to use other visual processing functions (such as the Dynamic Color mode on my Samsung LN37B650 from back in 2009).

As NCX said, most HDTVs have way too much gawd-damn input lag (even with Game Mode on). My brother plays a lot of fighting games so he always leaves his HDTV in Game Mode. He'd like one of those displays that are specifically engineered to not have input lag. I also never use the pre-set motion interpolation options. Instead I set it to custom and adjust the sliders myself to achieve the desired effect. That is, if the HDTV allows it, of course.

I have found that sometimes 240 Hz causes more input lag than 120 Hz (but it really depends on the TV). In other cases, like playing GTA V on X360, the 240 Hz does a way better job of improving the perceived framerate than 120 Hz, especially when there are severe framerate drops.

I agree that calling HDTVs "120 Hz" or "240 Hz" is stupid as fuck. They are referring to motion interpolation, not the display's refresh rate. Stop fucking confusing customers. I also can't tell you how many people I've run into who think that "LED HDTVs" are using a new, different fucking display technology. Thinks to the way shit is marketed, consumers don't realize that LED-backlit (or sidelit) HDTVs are still LCD displays. If it was an OLED display, then sure they would be right. But I digress.

I'd like to get more chances to screw around with actual 120 Hz refresh rate monitors. A friend of mine had one for years but I barely got to use it (plus it only had a TN panel, it was one of the first-gen 120 Hz monitors). One thing I can say is that it is definitely easier on my tired old eyes. Plus when I turn VSYNC on, the framerate is capped to 120 fps instead of 60 fps. I'd really like to see such a high refresh rate on a monitor that uses something other than a damn TN panel.
 
DIYmaster said:
@hajalie24 That's total horse shit. How you figure 120hz = input lag again?
Click to expand...

With interpolation on, which is what 120hz on a TV is, there is significantly more input lag.

This is because instead of immediately displaying a frame when it is sent from the source (console, cable box, etc.) it waits for the next frame and does calculations to create extra frames in between to smooth out the motion, then displays those frames. So if you are playing a console game at 60 fps on a TV with interpolation turned on it will add at least an extra 16 ms of input lag.

The good thing is most TVs have the option to turn this off.
 
Yes Sony W6 (now W7) is fantastic. It's not a high performance gaming monitor but when it comes to big screen gaming there's nothing better.
Even the upscaling of lower resolutions is pretty good.
Here's a very nice review, it's not pc gaming oriented but you'll find precious information in it;
http://shmups.system11.org/viewtopic.php?f=6&t=48662
W7 is almost identical so the review is also valid for that one.
Both W6 & W7 also reviewed on hdtvtest.co.uk -> must read.
 
hajalie24 said:
120hz TV"s aren't actually 120hz. They interpolate the frames .
Click to expand...

Interestingly enough, interpolation isn't the only game in town any more for so called "120hz" TVs. With recent displays there's the Impulse/Strobe Method which reduces motion blur without the lag/artifacting downsides of interpolation.

Interpolation Method
Advantages: No flicker!
Disadvantages: Artifacts, latency (input lag)

Impulse/Strobe/Scanning Method (CRT style)
Advantages: Low latency suitable for computer and games, lower frame rate needed
Disadvantages: Flicker, dim picture (short strobes needs lots of backlight brightness)
Click to expand...

http://www.blurbusters.com/faq/scanningbacklight/
http://www.blurbusters.com/sony-motionflow-impulse-mode-reduces-motion-blur-without-interpolation/
 
Good information all..

However, the 120Hz TV I have is a Westinghouse 40". It is not even a "smart TV".

But, when checking what Hz it is running at through OSD, it shows that it is running at 60Hz when I have my "smart" Sony BR player, console, or older computer hooked up. I haven't actually checked to see how the 120Hz input works, but from what I can tell, it is basically a 120Hz computer monitor with a TV Tuner included.

There are no options for interpolation. It is a pretty basic "TV".

The post above mine was not there when I hit reply. I am pretty sure my TV doesn't use the strobe method either as it is a pretty bright screen. I'll have to test it out when I get a chance.
 
cyclone3d said:
I haven't actually checked to see how the 120Hz input works, but from what I can tell, it is basically a 120Hz computer monitor with a TV Tuner included.

There are no options for interpolation. It is a pretty basic "TV".
Click to expand...

No need, it is 60hz. The TV's capable of true 120hz need to be overclocked, and can only be overclocked when using a PC. TV's Motion interpolation features are never named motion interpolation.
 
evilsofa said:
Because 120 is the first number that can be divided into both 24 and 30. Most film and video content displays at 24FPS, 30FPS or 60FPS. 120Hz allows 5 duplicate frames of 24FPS content or 4 duplicate frames of 30FPS content to be displayed.

Really it's 23.997, 29.997, etc. for technical reasons but it's just easier to talk about 24FPS. 30FPS and so on.
Click to expand...

evilsofa beat me to it. A lot of 60 FPS TVs have motion problems with 24 FPS content http://en.wikipedia.org/wiki/Three-two_pull_down

120 just lets you show each frame five times.
 
DIYmaster said:
@hajalie24 That's total horse shit. How you figure 120hz = input lag again?
Click to expand...

Not BS. If you're going to be a dick, get your facts straight.

I'll give you a hint: monitors that can accept a 120Hz signal are very different from TVs that are advertised as 120Hz.


OP: evilsofa's explanation is right.
 
120 Hz is a refresh rate.
That means that it can display that many frames.

Without any interpolation at all, 120Hz is better for a TV because it can natively display nearly all current content:
24Hz (repeat the frame 5 times)
30Hz (repeat the frame 4 times)
60Hz (repeat the frame 2 times)


This lets you display the content without having to do pulldown post processing.

Now.... what if you wanted to do something else besides repeating the exact frame? Well, you can do interpolation (which is super common and I, personally, can't stand it).
So instead of repeating that 60Hz frame twice, you take the two adjacent frames and you try to insert what you expect would have come between them.... making it "smoother"
 
This was the most helpful thread I have read in a long time.
I have spent a long time passing up on good priced HDTV displays because they are only 60Hz.
After reading the comments above, I am betting that 60Hz displays will not be obsolete quite as quickly as I was previously thinking.

I hope I get the opportunity to experience a high quality IPS display running at true 120Hz in a high resolution.
 
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