# 120 Hz vs 60Hz LCD TV sets and DirecTV



## Rose (Jun 16, 2008)

Many new LCD sets are 120 Hz, as opposed to the older 60Hz standard.

Do the new 120Hz sets offer any advantage to DirecTV HD DVR users?


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## LameLefty (Sep 29, 2006)

Rose said:


> Many new LCD sets are 120 Hz, as opposed to the older 60Hz standard.
> 
> Do the new 120Hz sets offer any advantage to DirecTV HD DVR users?


Since the whole goal of a 120 Hz refresh rate is to use an integer multiple of 24 to avoid having to do 3:2 pull-down processing of the source material, such sets might conceivably offer the ability to properly receive and display 1080p/24 VOD programing from Directv, something a great number of 1080p/60 sets cannot do.


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## GlennJ84 (Sep 27, 2007)

Rose said:


> Many new LCD sets are 120 Hz, as opposed to the older 60Hz standard.
> 
> Do the new 120Hz sets offer any advantage to DirecTV HD DVR users?


I find that my XBRs have less video 'judder' but its not necessarily as "night and day" on the DIRECTV HR21 as it is on the Blu-Ray.

I didn't really notice the difference in video quality between BR and HD(Directv) until I purchased a 120Hz Display. The Constraints of the bandwith allocated to each channel is easily visible. However, some additional video processing does help the picture a little. It just can't turn apples to apple pie instantly. The old saying is Garbage in = Garbage out. Not saying the signal is bad, just saying there is a reason Disk Based media still exhists ( at least right now)


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## dettxw (Nov 21, 2007)

Rose said:


> Many new LCD sets are 120 Hz, as opposed to the older 60Hz standard.
> 
> Do the new 120Hz sets offer any advantage to DirecTV HD DVR users?


You have to watch out for 120Hz sets that still do the 3:2 pulldown. These are simply 60Hz sets with double the refresh rate. 1080p/24 is becoming more widely supported on newer sets. Going to have to do your research before buying one. 
I'm looking at Samsung's PN50A650 or LN52A650.

Also have to watch out for some sets like the Panasonic TH-50PZ800U that only does 1080p/24 at 48 Hz, slow enough for your eye to detect the refresh. They should have bumped it up to 96.


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## Stuart Sweet (Jun 19, 2006)

Realistically, I'm waiting for 2160p/120, with support for 720p, 1080i, 1080p24, and 1080p60. By using 2160p, you can watch a 1280x720 or 1920x1080 source with no interpolation, and by supporting 24 and 60 Hz natively you can avoid all pulldown. 

Should be awesome, when I can afford it.


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## dcowboy7 (May 23, 2008)

the sony xbr 120hzs with the motion flow makes blu-rays look tremendous....it gives it that live look....like looking thru a window as opposed to the old just flat film look.


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## studdad (Aug 11, 2008)

dcowboy7 said:


> the sony xbr 120hzs with the motion flow makes blu-rays look tremendous....it gives it that live look....like looking thru a window as opposed to the old just flat film look.


ditto on the Samsung 750 line.


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## Grentz (Jan 10, 2007)

The best thing I have found is to go out and look for yourself at the difference. Some peoples eyes see a larger difference than others. Its not just "how" good your eyes are, it is preference.

I have some friends that absolutely love the look of the 120hz sets, personally I dont dislike them, but have no need for them either as I like the 60hz sets just fine. There is a different movement action between the two that you can like or dislike.

Saying that a 120hz set is simply better compared to a 60hz one is a fallacy.


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## TomCat (Aug 31, 2002)

The only possible improvements that 120 Hz displays could impart would be either a reduction of perceived flicker, or the removal of pulldown judder. But can they really impart such improvements? Yes and no (or no and yes). While eliminating pulldown for 1080p24 content (only) is indeed a slight improvement over not removing its inherent judder, reduction of flicker is not really something that increasing the refresh rate can accomplish, or even needs to.

Due to persisitence of vision, flicker is not really an issue even in 60 Hz displays. If the screen were blanked for part of the frame, as is the case with film or CRT, there would be more chance to perceive flicker at high refresh rates such as 60 Hz. But it's not, and there isn't.

So, since modern flat-panel displays do not suffer from aggregate compounded flicker issues as do CRTs (where there is a flying spot raster generated implying that most of the time any particular part of the field is not illuminated) and film projectors (where the shutter must be pulled down to obscure the film as each new frame is put in place, also implying a period of no illumination) the only real factor involved in the perception of flicker for LCD, plasma, and DLP is human persistence of vision, of which the threshold is about 1/50th of a second.

It then follows that a refresh rate for such displays _greater _than 50 fps should be enough to account fully for persistence of vision, and for any display with a refresh rate higher than 50 fps, there would therefore be no flicker issue to improve upon. A typical 1080p HDTV refreshes at 60 (actually 59.97) fps. It then also follows that increasing the refresh rate can't then improve the PQ by reducing flicker, as there is none to reduce above 50 Hz, and that includes 59.97 Hz. This is borne out by simply viewing a modern display. Modern displays do not exhibit flicker issues at all, even at a refresh rate of 60 Hz.

So, it seems that the only reason to increase the refresh rate is, as LameLefty points out, to make the lowest common denominator something that both 60 and 24 can divide into thereby eliminating pulldown and its inherent judder.

The hype-meisters would like us to believe that a 120 Hz refresh rate also implies a more-solid picture than 60 Hz, but it appears that this is not really possible, since the human vision system can't detect refresh below 50 Hz, and would perceive anything above a refresh of 50 Hz as solid unbroken motion.


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## hdtvfan0001 (Jul 28, 2004)

Grentz said:


> The best thing I have found is to go out and look for yourself at the difference. Some peoples eyes see a larger difference than others. Its not just "how" good your eyes are, it is preference.
> 
> I have some friends that absolutely love the look of the 120hz sets, personally I dont dislike them, but have no need for them either as I like the 60hz sets just fine. There is a different movement action between the two that you can like or dislike.
> 
> Saying that a 120hz set is simply better compared to a 60hz one is a fallacy.


I agree that its something people have to judge for themselves.

Since my wife works for a retail supplier in electronics and media, I had to wait for her recently for about 45 minutes, and actually just sat there and watched side-by-side units (one 60Hs and one 120Hz showing the exact same media content.

Personally, the difference watching 6 different action movie demos presented was almost non-existant IMHO. I saw perhaps 1 or 2 seconds over the 45 minutes where one could distinuish a very specific moment of a scene or portion of a scene that varied every so slightly.

To me, that would not warrant the difference in cost, if I have to stare at 2 TVs for almost an hour and see that tiny bit of difference...


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## rudeney (May 28, 2007)

Stuart Sweet said:


> Realistically, I'm waiting for 2160p/120, with support for 720p, 1080i, 1080p24, and 1080p60. By using 2160p, you can watch a 1280x720 or 1920x1080 source with no interpolation, and by supporting 24 and 60 Hz natively you can avoid all pulldown.


2160p is not all it's cracked up to be. Due to the digital info in the overscan area, you still need to crop (and thus interpolate) the picture for TV broadcasts or deal with annoying static at the top of the screen.


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## cwdonahue (Jun 6, 2007)

I have a Sony KDL-40V3000 that supports 60Hz and 1080p/24. Given it is a 40" screen and that may be a factor, I've never had any noticeable motion blur with football or other fast moving action with DirecTV. I also do not run my LCD in show room torch mode either, so that may help, too. I read mixed reviews for 120Hz sets, so I'm not yet sold on that technology.

I can now view DirecTV at 1080p24. I must say, it looked great on my Sony HDTV. I only viewed the Hulk trailer, but I've seen it before and it looked great.

So, I still remain somewhat skeptical on the whole 120Hz thing. I'm sure if it is done right that it works. Maybe my aging eyes are going bad, but I'm fine with my Sony LCD HDTV with only 60Hz and 24p support.


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## Hutchinshouse (Sep 28, 2006)

dcowboy7 said:


> the sony xbr 120hzs with the motion flow makes blu-rays look tremendous....it gives it that live look....like looking thru a window as opposed to the old just flat film look.


Fully agree. When we got our 52XBR4, my wife said "the video looks too real". 

:bowdown: *Sunrise Earth* is sick with motion flow set to high. It is like you're looking out a window.


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## dcowboy7 (May 23, 2008)

Hutchinshouse said:


> Fully agree. When we got our 52XBR4, my wife said "the video looks too real".
> 
> :bowdown: *Sunrise Earth* is sick with motion flow set to high. It is like you're looking out a window.


i know its so cool....i saw spiderman 3 on a 60hz and on a 120hz....the 60 it just looked like a regular film....on the 120 it really popped and had that "you are there" feel.


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## spartanstew (Nov 16, 2005)

120Hz alters the picture too much. It makes film look like video, which IMO is not good (and not like the director intended). I do see some benefits when watching sports, but would never use it for movies. Some people also like to leave their sets on "vivid" when they buy them, because they think the colors pop. It's still not accurate though. Accuracy is more important to me than altering the image.


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## dcowboy7 (May 23, 2008)

spartanstew said:


> 120Hz alters the picture too much. It makes film look like video, which IMO is not good (and not like the director intended).


fooey on the director....what makes him too cool for the room....i like the video look.


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## studdad (Aug 11, 2008)

dcowboy7 said:


> i know its so cool....i saw spiderman 3 on a 60hz and on a 120hz....the 60 it just looked like a regular film....on the 120 it really popped and had that "you are there" feel.


Exactly. I usually keep it on low, which does not give it too much of a "soap opera" look, but still gives it some added pop and realism. If I am watching a nature show I usually turn it up to High, and the picture is just incredible.


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## dettxw (Nov 21, 2007)

Hutchinshouse said:


> Fully agree. When we got our 52XBR4, my wife said "the video looks too real".
> 
> :bowdown: *Sunrise Earth* is sick with motion flow set to high. It is like you're looking out a window.


Isn't motion flow different and incompatible with 1080p/24? I thought that you had to turn motion flow off on a Sony in order to use 1080p/24.


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## videojanitor (Oct 8, 2006)

spartanstew said:


> 120Hz alters the picture too much. It makes film look like video, which IMO is not good (and not like the director intended).


I agree 100%. I hate the look of 120Hz displays, when looking at film-based content. Maybe it's just that I'm used to what film looks like (both projected, or transfered to video), but whatever -- I reserve the right not to like it! Fortunately, I think most of these sets enable the user to turn that feature off.


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## kiljoy (Apr 29, 2008)

videojanitor said:



> I agree 100%. I hate the look of 120Hz displays, when looking at film-based content. Maybe it's just that I'm used to what film looks like (both projected, or transfered to video), but whatever -- I reserve the right not to like it! Fortunately, I think most of these sets enable the user to turn that feature off.


I know the two most popular, Samsung and Sony, both do. I find that there are some sources where AMP/MotionFlow work quite well, and plenty others where they don't.

Also, dettxw, you're right. AMP/MotionFlow is frame interpolation, and 24fps would just be repeating the frame five times without interpolation.

That said, I love my Sammy 6-series. I'm really glad I went for the 120Hz over the 60Hz panel, I've used both and after this latest firmware revision I'm really happy with the three AMP settings.

Tony


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## BattleZone (Nov 13, 2007)

dettxw said:


> Isn't motion flow different and incompatible with 1080p/24? I thought that you had to turn motion flow off on a Sony in order to use 1080p/24.


Correct!!!

MotionFlow is great for live, video-based sources (read: sports), as that's what it was designed for. It *can* be like looking out a window.

But it needs to be turned off in order for 1080/24p to be refreshed correctly with 1 frame every 1/24th of a second. In this mode, film looks like film, and reproduces the theater experience very well.


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## rsonnens (Nov 8, 2006)

videojanitor said:


> I agree 100%. I hate the look of 120Hz displays, when looking at film-based content. Maybe it's just that I'm used to what film looks like (both projected, or transfered to video), but whatever -- I reserve the right not to like it! Fortunately, I think most of these sets enable the user to turn that feature off.


The effect may be different but these sets displays 24hz material at 24fps, so it makes it look like much more like the studio/director intended to look. Also, these sets still displays 60hz material at 60fps. Sets with 60hz refresh rates will make movies look worse than intended.

Film transfered to 60hz, and then displayed on a 120hz may should similar look the same assuming the set has good 3:3:2 pulldown detection and a proper inverse pulldown algorithm. If comparing two different sets it is possible that one set does not do this well and will cause a visual difference.

Other factors, and this is what you I think you see, is that many higher end sets include de-blurring technology for moving images caused by slow pixel switching . This is unrelated to being 120hz verses 60hz panel and will vary a lot by manufacturer. It is also unrelated to motion blur in the source material.

Slow pixel switching is inherent with LCD technology but so not much with Plasma and OLED---not sure about DLP. These technologies don't really need to worry about blurring introduced by the display technology.

But all this is academic because in the near future all sets will display input as some even multiple of the panels refresh rate--and I don't think you will be able to turn it off. It will then be other technology differences (and price) that will dictate which set to buy. [My guess is that OLED will be preferred for normal home usage in a few years.]


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