Everyone loves to talk about how
1080p at 24 frames per second is the holy grail of the ultimate HD movie experience. But the truth is that even if you are watching a Blu-ray movie via HDMI with the latest player set to 24p, there's a good chance it's all for naught because your HDTV is just converting the signal to another frame rate. But not all TVs do this, some can actually do it right and instead of using 2:3 pulldown it can do something like a 3:3 conversion and display the signal at 72hz -- for example. The problem of course is how can you tell which TVs do it right and which do it wrong? Well, thankfully a resourceful member of the
AVS Forum -- with some help of other members -- has comprised a list to save you the hassle. So if you're in the market for a new HDTV and you just have to watch your movies at the native frame rate, then head on over and pick one from the list of front projectors, rear projectors, LCDs, or plasmas.
Reader Comments (Page 1 of 1)
Prophet @ Feb 21st 2008 5:54PM
How about a link to the thread?
MrSlinky @ Feb 21st 2008 6:00PM
How about clicking the little 'Read' link above. Seems to work for me
Prophet @ Feb 21st 2008 6:14PM
Hmm guess so.
Tony @ Feb 21st 2008 5:55PM
Engadget links to tags instead of to the useful page on the mentioned site always pisses me off.
Harley3k @ Feb 21st 2008 6:08PM
uhm.... what?
longhairbilly @ Feb 21st 2008 6:21PM
There is NOTHING you can't find the answer to on the AVS forums. Best place on the internet.... I mean, besides Engadgethd of course..
Josh Poulson @ Feb 21st 2008 6:23PM
Click the "Read" link, people.
AlexHD @ Feb 21st 2008 6:30PM
This is one of my favourite things about Blu-ray, I hated pulldowns and PAL speedups on DVDs.
jonashpdx @ Feb 21st 2008 6:39PM
sorry, grammar nerd. "all for naught"
del1verance @ Feb 21st 2008 7:09PM
And all this time I thought my new TV supported 1080p24. Oops.
joe @ Feb 21st 2008 8:33PM
You are correct. All HD tv's at this point handle 24p. but this is the same way a 1440x1080 panel handles 1080i content.
Most lcd panels handle video at 60 hz. When a 60 hz display is fed 24 frame content it has to do interpolation to make the frames fit. This is the 3:2 pull down, what the graphic at the top refers to.
Some tvs run at a righer frame rate, such as 120hz. This allows it to show 24 frame material without interpolation. It shows the same frame 4x times but does not guess what the next frame should be.
120 is also optimal because it is a multiplier of 60hz so your native televisions show will not require a pull down either.
Reapman @ Feb 21st 2008 7:13PM
Damn I was sure my Sharp Aquos 82U did 1080p24. I iz sad :( I'll have to research it out to confirm. Although I guess ignorance is bliss since I'm pretty happy with the picture quality still!
why not the LS2LS7? @ Feb 22nd 2008 3:21AM
Well, my 92U doesn't do it (tried it with my PS3). So I'm pretty sure your 82U doesn't.
Michael McDaniel @ Feb 21st 2008 7:28PM
Shouldn't that be "all for naught?" Spell checkers making people dumber again!
Ben @ Feb 21st 2008 6:53PM
Yep you're right, I fixed it.
Thanks.
rekoil @ Feb 21st 2008 7:37PM
At the risk of sounding naive, is there any noticeable difference between 3-2 pulldown and real 1080p/24? Or is this more a marketing tool a la Deep Color?
Shape @ Feb 21st 2008 8:01PM
Yes, it is noticeable.
Joe @ Feb 21st 2008 8:33PM
It all depends on how well your tv or display handles the pull down. I think in most cases it shouldn't matter all that much.
It is noticeable in the sense that if you were watching native 24p content then switched to a pull down you would know something changed. Motion would look smoother .
jeb @ Feb 21st 2008 8:14PM
isn't 1080p 60 better than 1080p 24?
Joe @ Feb 21st 2008 8:46PM
No. If the source material you are watching, dvd or BD is mastered at 24 fps the TV will have to guess at some frames to make 24 frames fit into 60.
Jouten @ Feb 21st 2008 8:29PM
Until ALL tv/cable companies can broadcast 1080p, and I allow myself to sit within 6 feet or so in front of my 50" Samsung plasma (768p), the point is moot. I know there are even 1080p fanboys out there for God's sake, but I will focus on the source, contrast and color saturation and accuracy BEFORE resolution (1080p). Thanks for the new breed of resolution fanboys Marketing Hype!
Joe @ Feb 21st 2008 8:47PM
All of those items are great to focus on, they have a greater overall impact on how the image looks.
This doesn't have anything to do with 1080p. The frame rate issue affects 720p sets just as much as 1080p sets. 1080i is an abomination that should have never been.
Color has the greatest influence on picture quality.resolution will be next, then comes motion.
The interlace (i/p) and the native frame rate issues are two issues that deal with moving images. Some people will not be able to tell the difference between 24p native and 24p interpolated to 60i. This is the same as people who can't see the difference between sd and hd content or see a difference in LCD black levels.
I tend to watch moving images at home so I care quite a bit about that part seeing as color is as good as it can get for now.
YMMV
why not the LS2LS7? @ Feb 22nd 2008 3:22AM
Let me call the whaaaaambulance!
Sorry if my 1080P TV offends you. I'll tell you this, it looks great on 1080i input, on 720p input and on BluRay 1080p input, which is available to EVERYONE TODAY.
Bob Mc @ Feb 21st 2008 8:36PM
Frak! Yet another reason to buy an expensive Kuro.
locke6854 @ Feb 21st 2008 11:50PM
the bravias (w and v) use 48hz. it gets rid of the 2:3 cadence but causes a subliminal flickering. But i'm not sure I understand the flickering, since lcds are sample-and-hold, right? My lcd pc monitor @60hz looks the same as my crt at 100hz, flicker-wise.
locke6854 @ Feb 21st 2008 11:55PM
now, i have a v3000 and 24p works "smoothly", but heres where i was getting the 48hz info from-
http://www.pcmag.com/article2/0,2704,2210884,00.asp
5th paragraph
HDpurist @ Feb 22nd 2008 1:28AM
THANK YOU PIONEER!
My 50" 1080p plasma is perfect. Too bad not everyone can experience the awesomeness of Kuro. The PQ blows my mind everytime I turn it on with it's inky blacks and godly CR. Amazing, the best TVs every produced.
anon @ Feb 22nd 2008 11:36AM
Lucky. I really wanted one of those Kuro's, but the wife almost had a heart attack when she saw the price and put an end to that thought. So I get an SXRD instead. I love that TV, but I often think about what could have been...
GhostDoggy @ Feb 22nd 2008 5:45AM
Most people sit too far from their screens to be able to see the native resolution of their displays. In order to see 1100 line pairs (1100 lines of resolution) you have to have 20-20 vision and be no farther than 1.5 times the screen's width away. Any farther and you will lose that ability to resolve the native resolution.
So, what difference does it make what is being fed to your fixed-pixel display? How many of you sit at or within the 1.5X screen width boundary? I only do this in my home theater, but then again that image is 80" wide (92" diagonal).
indadogghouse @ Feb 22nd 2008 10:36AM
Aren't we just taking about 1080p24 vs 1080p60? Only content available in 1080p24 are BR movies now. Heck, only content that's even 1080p.
So, 1080p24 feature right now is only good if you have 1080p24 source. Displaying 1080p24 on a 1080p60 set results in this 2:3 cadence. Don't think any interpolation is done, just frames are replicated. The only problem this causes is during slow panning or slow continuous moving scenes, a stutter may be noticed, nothing else. No affect in resolution.
Let's say you capture 24 image frames panning your camera slowly left to right, let's say in 1s. You display them back in ls and everything looks as it does. Now, you want to display 60 frames in 1s, but you only have 24 frames. You decide to display every frame twice, but that only makes 48 frames, you're still 12 frames short. So every other frame of the original 24, you decide to display that frame 1 addtional time for a total of 3 times (24-12 = 12). Okay so you've got your 60 frames. However, it's this additional 3rd replicated frame that causes the stuttering because your eyes are noticing a time lag between "new" frame updates. For instance, frame 1 of the original 24 is displayed for 2 cycles or a total of ~33ms (1/60 * 2), frame 2 of the original 24 is then displayed for 50ms (1/60 * 3), frame 3 for 33ms, frame 4 for 50ms, and so forth. If the image pan or motion in the video is slow enough, your eyes will pick up this 17ms difference between frames, like the video is pausing for a brief moment because that's essentially what's happening, the video is pausing every other frame for 17ms.
1080p24 capability doesn't help improve 1080i or 720p native source, it will be essentially the same as 1080p60, just displays at a higher refresh rate. What you say? Higher refresh rate? 24 isn't greater than 60. Google around, there's plenty of info on this. I haven't been keeping up on the tech, so things may be a little different.
earthling @ Feb 22nd 2008 10:41AM
There is a lot of confusion in that post on AVSforum.
First, it makes the rather HUGE assumption that you actually want to SEE 24 frame motion on your screen. There is a huge difference between watching a film at the theater which is being displayed at 24/72 (24 frames, refreshed 3x per frame or 72hz) and watching something on your television. When you are at the theater you cannot focus on the entire screen at the same time, this is one of the basic premises of the 'cinema' experience. You simply don't notice the motion judder (as much) caused by the low refresh rate because you are only focused on a small area of the film frame at any given time. Your brain is doing a lot of interpolation outside of your immediate area of focus. The closer you are to the screen the more this is true. In a television viewing experience you can always see enough of the screen that the motion judder is very evident. Television engineers understand this so they have come up with interpolation methods which disguise the judder effect.
In case you do not know.. Judder is the effect you see when objects that are moving on the screen do not seem to be moving quickly. Film, at 24 frames per second lacks the ability to capture frames quickly enough to make the motion fluid. You see this most often when the camera pans horizontally and the scene seems to stutter (judder).
Secondly, I wish the OP in that thread would stop saying 3:2 pulldown.
2:3 is the act of converting film to video and it is known as 2:3 pulldown
http://en.wikipedia.org/wiki/3:2_pulldown#2:3_pulldown
3:2 is the act of converting video back to its film source (with mixed results all the time)and it is known as 3:2 pull up.
and the rest of the ratios that the marketing types have made up (4:4, 5:5) are pure marketing malarky and make no sense. It would be more proper to call it 1:4 and 1:5 since each input frame is refreshed 'n' amount of times IOW 1 frame in equals 4 frames out so 24hz becomes 96 hertz and so forth but even that is incorrect since the refresh rate has no correlation to the stored or interpolated frame rate except that in this case they happen to be the same. When the OP is talking about the interpolation between 24hz and 60hz frame rates(non integer values) it is not 3:2 it is a 2:3 pulldown but even that is not accurate and it causes a ton of confusion since pulldown refers to fields and this is not fields it is progressive content. Meaning that anyone who has learned the difference between progressive frames and interlaced television will be confused by the similar but incorrect reference.
@joe 120hz refresh is optimal not for the reasons you state.
There are two reasons that 120hz refresh is optimal.
1. And this is the primary one, it is easier for the marketing types to explain it as 120hz refresh rate rather than to talk about response times. To tell someone that their LCD monitor has 10ms response times is harder to defend because someone else is always going to claim that their monitor has 9ms which seems better. It is far easier for the marketing/sales/press people to talk about 120hz refresh rates because the benefit is easier to explain. The bottom line however is that 72hz is enough, as is 96hz.
2. It is an integer multiple of the frequency of the lighting in your house. This is why 72hz and 96hz (as well as 48hz) simply look bad. The lighting in your house is refreshing at a different rate than the monitor is causing a beat frequency and all kinds of bad effects. To see this watch a 50hz pal television in any north american home. IT LOOKS BAD.
Also, I would disagree with your comments about the most important factors of a television. Color may be the most impressive but resolution is the most important, followed by color, then refresh rate.
The bottom line about the AVS thread is that 99% of the people there probably cannot tell the difference between 120hz non interpolated frame rates and 120hz interpolated frames so the list is all but pointless except as a benchmark for choosing a new television. Anyone who has a recent, 120hz television who is thinking of buying one on the list is probably doing so for the wrong reasons (contrast ratio is far more important for instance).
locke6854 @ Feb 23rd 2008 5:08PM
2:3 and 3:2 are interchangable. Theres no difference. Its a 2-3-2-3 cadence. If anything, the "A" frame would be displayed 3 times with 3:2, and the "B" twice. But its still "pulldown" and it would look the same regardless if the video started with 3 identical frames or 2 identical frames.
As for "pull-up", i'm not sure thats even a term. Actually, 2:3 pulldown is the "telecine process" and your pull-up is called "inverse telecine".
I'll also disagree with resolution being the most important factor to image quality. I'd say contrast/color trumps resolution.
daaper @ Feb 22nd 2008 1:31PM
sweet, my Sony KDS-60A3000 is on there. It makes me feel a little better when I read that all the marketing isn't just hype. It really bothers me when company cheat their stats like "contrast ratio", "peak power", etc. How about just making a better product?
Joe @ Feb 22nd 2008 2:39PM
Earthling-
When you get into the realm of Videophile people always want to see things as close to the source as possible.
You are incorrect about motion picture theatrical judder. There is no judder in motion picture film. The film is shot at 24 fps and displayed at 24 fps. Any objects moving too quickly in the original scene will produce a motion blur on the film. This will be faithfully projected. Motion blur is an integral part of the cinema look. That is why the Ray Harryhausen skeletons looked eerie,they had no motion blur.
Judder is a specific effect that only applies to telecine and the pull down process.
In this case it is proper to call the conversion a 3:2 pulldown. When a tv at 60hz is fed a 24hz source it needs to make the same conversion that a telecine does.
A "pullup" case would be where a movie was shot a 24 fps was telecine'd at 60 fps then was converted back to 24fps. This is more commonly called reverse telecine. HDM gives us the opportunity to by pass that by using a true 24p source to a 24 p display.
Refresh rate and response time are theoretically independent. In practical display applications there is some overlap.
First response times in ms that LCD displays give are misleading. What you want to know is the GTG or grey to grey time. Turning an LCD crystal from full on to full off is pretty easy to do. When you go from a 80% grey to a 20% grey the crystal has to do a full cycle. It needs to go from 80% to full off to 20%. That takes much longer.
Refresh rate is the rate of video processing directed to the panel. In crt displays the display was truly variable and could natively be addressed at a variety of refresh rates.
LCD panels can only be addressed at the native driver rate. You can not send a 48hz signal to a 60hz panel. It will be out of phase and cause all sorts of crazy looking artifacts. The signals need to be convereted to the native panel display rate.
Since the best way to get an unchanged signal to the panel is to repeat it. So a 30hz signal can go 2x to a 60hz panel with no changes.
120hz is an ideal number as it is the smallest frame rate that is both a multiplier of 60 and 24. 60 hz signal are displayed 2x 24 fps signals are displayed 5x. 72 of 96 hz is perfect for film but it is no good for video since it is not a native multiplier of 60hz. That would require video to be processed.
To get back to panel refresh rate 120hz displays are out now because of improvements in LCD technology ips being a big change. A 60 hz signal requires approximately a 16 ms response time. Thus a 120hs signal requires a 8ms response time.
This requires the latest and greatest and is why you are only seeing higher end displays supporting the 120hz refresh rates.
You are also confusing a lot of different issues on frequency. North American NTSC television is at 60hz the same as your lighting. There is no interference between traditional TV and your lights and you should expect none suddenly in the future.
As much as I love 1080p it is not the most important factor to image quality. Provided you don't have artifacts or weird motion effects, proper contrast is the most important for image quality. The next is Hue, then saturation. That is why many people can live with SDTV.