What is Digg?58 Comments
- Mugsleymug, on 10/12/2007, -3/+23the eyes seeing 20fps thing is a myth. the reason film looks good at 24fps is because movies incorporate motion blur. Video games dont (usually) use motion blur, so framerate matters. If you lower the framerate in a game to 24fps and add some motion blur technology, you usually get a very nice movie-like effect.
- scottmoss, on 10/12/2007, -4/+22Solution #1 buy a good quality monitor, Samsung is good, so is Sony but stay away from Visio...
- pegisys, on 10/12/2007, -1/+16Really I have heard some good things about Visio, I was thinking about getting one for the bedroom
I'm willing to bet higher refresh rates aren't going to provide much better of a picture if the video your sending to your TV is 24-30fps, if anything they need to get response times even lower while still being able to have a full color range, that should be top priority
EDIT:
"i can spot a 60hz display from about 50 feet away, it hurts my eyes, something displayed at 120hz is so smooth, it puts less strain on your eyes"
on a CRT yeah, but LCD's don't scan so your not going to get any flicker - ForkySpoony, on 10/12/2007, -2/+15Actually the eye can detect much higher frame rates. The only reason movies look so smooth to the eye is because of motion blur.
The problem is that the human eye does not perceive "frames". For example, some cells in the eye actually only perceive motion and not static objects
http://www.100fps.com/how_many_frames_can_humans_see.htm - Philodox, on 10/12/2007, -1/+12the refresh rate on an LCD doesn't really matter, it's the response time. My LCD monitor's refresh rate is 60Hz, but it's response time is 8.5ms so I've never seen it blur.
- Kniggit, on 10/12/2007, -3/+14Ok, so let me tackle this one since I was working on motion compensated frame rate converters (MCFRC) for actual flat panels and digital televisions.
First of all, human perception can directly detect frame rates as high as 70-100 fps, depending on the individual, and indirectly using other visual clues even higher than that. However, the 24fps of film is of critical importance to the suspension of reality that is inherent to the user experience.
NOW...
Motion compensated frame rate conversion has existed for a while now in various different forms. One notable broadcast maker who shall remain unnamed is the expert at it using something called phase plane correlation. This tracks object motion at a sub-pixel level and interpolates it between known good frames. They make broadcast equipment, and their algorithm is generally considered the best (and most computationally expensive) approach. I can tell you that there are companies working with some big panel manufacturers to provide superior solutions even to their approach. The first commercial algorithms MCFRC implemented in flat panels came from the original motion compensation motion estimation (a.k.a. MEMC) engines in MPEG-2 encoders in the form of what is known as block-based MCFRC. The blocks are pretty big, however, and are normally at least 8x8 in size - not exactly accurate. There are some other classes of MCFRC as well, but these are the two most significant.
Most televisions today use something called add-drop frame rate conversion where they literally either repeat frames or remove frames in a pre-calculated sequence. Unfortunately, due to the inherent limitations of LCD technology, you get some artifacts known as motion judder and motion blur. Motion judder looks like the scene is shaking around (particularly during a horizontal or vertical pan), and it's a very noticeable and distracting phenomenon. By filling in the frames with estimated information about background and foreground objects, you greatly reduce or eliminate this shaking phenomenon.
And that is the trick. Figuring out what is a moving object versus what is background is a very very very difficult thing to do! Why, you may ask? Well, what happens when the background changes between frames behind moving objects where the information simply didn't exist? What happens if an object is transparent? What about multiple layers of objects on top of each other? What if the object is changing in size or three dimensional position where intermediate information about the object would be impossible to determine? The reality is that this is one of the most challenging image processing problems because concealing the errors and filling information in where literally none existed before is where all the magic of MCFRC occurs. That famous commercial with the falling marbles is one of the toughest benchmarks for this purpose.
The block-based MCFRC algorithms that exist today are, in my opinion, NOT suitable for digital televisions. While they're great for scenes with little "foreground" information, like panning scenes with distant non-significant moving objects, they introduce artifacts that make the foreground objects appear to have a very strange shimmering blocky border around them. One example of this is the high-end Philips LCD with this technology (now part of NXP's Nexperia DTV platform). It's very ugly and very noticeable block-type artifacts around the objects. You can actually buy them today, but I wouldn't touch one myself if it was given to me. The only suitable MCFRC is a phase-plane correlation method, and you won't start seeing it in production flat panels until 2009 high-end models at the very earliest. The blocks aren't there, but you will occasionally see some strange blips here and there.
More important than all of this is the travesty that will be hoisted on all of us with this technology no matter which technique is used. That travesty is the elimination of the 24fps film frame rate that is currently handled using 3:2 pulldown with frame repetition. MOST of the time it is very visually pleasing to have true film frame rate and results in the suspension of reality that I was just speaking of. Have you noticed that a movie looks different than a video? There's a reason for that, and you don't want film looking like video. And yet, that's EXACTLY what is going to happen, and it WILL ruin your user experience with all film content. This technology will make your video look extremely plastic even if there is perfect inter-frame interpolation of motion. Unless you have the option to turn it off in a menu, you'll be very disappointed in your purchase.
You also have probably seen what this looks like before. Remember pan-and-scan? When they take a 16:9 or higher wide aspect ratio movie and only record a 4:3 portion of it for regular televisions, there are portions of the action that change within the frame. You'll notice that pan-and-scan makes the movie momentarily look very (unnaturally) smooth, and then normal again as the subjects within the viewable area are re-targeted. Imagine what it will look like if it's like that ALL the time. It won't be a movie any more.
You heard it here first. - Darmichar, on 10/12/2007, -2/+9A higher refresh rate on a monitor (anything higher than 60Hz) will generally look better/have less flicker because it isn't 'clashing' with the 60Hz 'refresh rates' of the lighting around it.
- thtroyer, on 10/12/2007, -0/+7It's a bit more complex than that. For example - people can see 'flicker' up to 75 Hz, so you can't use 24fps/Hz is good enough for anything and everything.
- NoHandle, on 10/12/2007, -0/+6Though I have heard the same information before and partially agree, there is also the fact that people report having headaches and other problems from a 60Hz refresh rate because, though you cannot physically detect the difference, you still detect a difference. I notice a fairly large difference between 75 and 60 Hertz. I prefer the higher rate because the screen looks more "steady"
However, as for going up to and past 100Hz seems a bit over the top. Especially since the need for the higher rate is generally a result of reading small text on a white background, or at least for myself it is. - Cuja, on 10/12/2007, -0/+5The part I find funny is that everyone is talking like they really can see the refresh. What you see is how your monitor/TV/LCD is out of sync with the lights that you use. Fluorescent lights are the worst and literally are flashing at 60 cycles. That is why in Best Buy/name your local big box store (or at work) it's really easy to see the "rolling" effect on their Computer monitors but you'll notice that for their TV section there are very few fluorescent lights. If you live in the US everything runs off of 60hz. Europe I think is 50hz. It's how AC power works (in a very simplified definition), that's what you "see" in reality. The out of sync effect.
- exobyte, on 10/12/2007, -2/+7I was told that Sony uses Samsung displays (they just rebrand them)
- sockpuppets, on 10/12/2007, -3/+7Clearly this guy's dog has learned to type despite his lack of opposable digits.
- Zreitan, on 10/12/2007, -0/+4its more complciated then FPS with us humans. i think i read somewhere the picture we get from our eyes is somewhere near a 50 mega pixel image...that's a lot of processing even at 15fps which i think is higher then that... plus we have different sorts of blind spots, and we selectivly see things.
- seanmac, on 10/12/2007, -0/+3Wow I read that entire post but I was rewarded in the end with that little nugget about pan-and-scan. I always wondered why that looked weird.
- illt, on 10/12/2007, -0/+3i was under the impression LCD"s are always on, rather than being drawn line by line at a frq.
- reevolutn, on 10/12/2007, -1/+4@exobyte
i think you mean dell uses samsung? i think - Midnightbrewer, on 10/12/2007, -0/+3Kniggit said:
"You also have probably seen what this looks like before. Remember pan-and-scan? When they take a 16:9 or higher wide aspect ratio movie and only record a 4:3 portion of it for regular televisions, there are portions of the action that change within the frame. You'll notice that pan-and-scan makes the movie momentarily look very (unnaturally) smooth, and then normal again as the subjects within the viewable area are re-targeted. Imagine what it will look like if it's like that ALL the time. It won't be a movie any more."
How is frame interpolation the same as pan-and-scan? First of all, since pan-and-scan is only for 4:3 aspect ratio screens, and most if not all televisions will be 16:9 by 2009, it will no longer be an issue. Secondly, you said it yourself: film will never look like television, because of the motion blur. No matter how good your frame interpolation technology is, we're a ways from being able to turn 24-fps motion-blurred video into non-blurred 30-fps video. The grain and motion blur will remain, so the film will continue to look like film. That being said, I was able to successfully film a "film look" video using a prosumer Panasonic camera from three years ago, because it could be set to a cinematic color gamut and true, full 30fps (not fields, but frames.) Even my television production colleagues were impressed with the results, wondering if I hadn't used a 24p camera instead. - tuxidomasx, on 10/12/2007, -0/+2i was about to make this point. well said.
framerate doesnt mean anything to an LCD. just response time - mercurysquad, on 10/12/2007, -0/+3"we don't see in pixels"
Wrong. While we don't see in pixels in the literal sense of the word, our field of view of 270 degree section of a sphere has a finite angular resolving power. This angular resolving power is analogous to the resoultion of a digital camera. Depending on the field of view of a digital camera, you can literally compare the eye's resolution to a camera's, in megapixels. - Kniggit, on 10/12/2007, -0/+2@midnighbrewer:
How do you think the panning looks smooth when the subject pans across the frame? You have a limited number of usually non-integer pixel boundaries on intermediate frames in the pan as you pan across over a given number of frames. On top of that, you have at least one and usually two competing degrees of freedom (pan window and background). If you don't interpolate frames using motion compensation, you can severely judder the picture (and judder was all I was talking about). Pan-and-scan was merely an example that I used to illustrate the aesthetic effects of MCFRC to people who don't know what it looks like.
Film look is film look, period. I used to consult for people in your business, incidentally, and the best way to get the film look based on frame rate alone was to do what's called "NTSC film" which does inverse pull-down and brings the frame rate it to 23.976fps by repeating some of the fields which then match the 59.94 fields/s. I agree fully that you also need proper lighting, subject framing within the camera, iris control + ND filters for depth of field, film emulsion grain simulation, and all the proper cinematography techniques that are used in real films. You will, however, severely compromise all of that if your frame rate is wrong.
In fact, if you're distributing content on DVD and you're not using "NTSC film" rates in your authoring when your footage was shot in 60 interlaced field per second rates, you're potentially wasting valuable DVD space that could be used to increase the quality of it. MPEG-2 in DVDs has a repeat field flag to repeat fields for inverse pull-down so that it actually matches NTSC field rates. Publishing and capturing in PAL is somewhat better in this respect since you go 25p from 50i by pushing what's called progressive segmented frame, but this has always been problematic because it requires you pitch-shift or speed up your audio track from what would've normally done or you have to go back to NTSC. In addition, if you do NTSC to PAL for this purpose, you have to deinterlace and scale which will introduce visual artifacts associated with those processes. That's two other separate topics of their own.
By the way, FRC is also a potential way to simulate overcranking when you don't have $10k+ a day to rent a digital overcranking camera. I'm just waiting for the makers of editing software to get their act together to see if they'll ever do this. If you're producing video, this would be a great way to save yourself a few bucks or utilize your B-roll on some of your other cameras to get that smooth slo-mo. Then again, if you're that hard up on film look you should probably just rent a 16mm or 35mm film camera. - SrLnclt, on 10/12/2007, -0/+2"A new technology refreshes TV images at 120 to 100 hertz, or 120 to 100 times a second..."
If you didn't already know hertz means cycles per second, you shouldn't be reading tech articles. - scabbers, on 10/12/2007, -1/+3You won't hear the high pitched noise from screens once you become older.
- Mugsleymug, on 10/12/2007, -1/+3i can hear that high pitched noise too and most people i know do, too. Theres a TV in our local EBGames that's obviously not meant to be set to 60hz but it is and when you're in the store it HURTS. The staff can't hear it though.
I find it very easy to point it out to someone if you sit on a GCN game screen that says "60hz?" and you have a TV rated for 50hz as soon as you press A, you will notice the different sound, but on most TVs, you stop noticing it after a little while especially without background noise. This one in our EBGames though is terrible.
We can all tell the difference between 30 - 60 - 100FPS, too. - sockpuppets, on 10/12/2007, -1/+3Lol, you didn't even read the article, did you?
- inactive, on 10/12/2007, -2/+4we don't see in pixels
- smb3d, on 10/12/2007, -0/+1Lots of people seem to really like the Aquos. I had a 32" Sharp Aquos and took it back for a Sony Bravia. The Aquos looked like it had window tint over the image, no matter how I calibrated it.
- Dog_Paddle, on 10/12/2007, -1/+2gwagaw
- pixelbeat_, on 10/12/2007, -0/+1I bought a samsung LCD LE27T51B a while back,
and sent it back because of the awful digital processing.
This was actually being done by micronas and genesis
ICs and design. Details here:
http://www.pixelbeat.org/systems/LE27T51B/
In summary, there is lots of room for improvement
in the processing electronics and panels of LCDs,
so don't rush into buying one at present. - Gizza, on 10/12/2007, -0/+1I was thinking the same thing. LCDs dont refresh their image. So im not sure what this is actually meant to be doing.
The only time refresh rate on a LCD makes a difference is if your playing a game with vertical sync on. But then its more of a graphics card issue than a monitor issue. - inactive, on 10/12/2007, -0/+1To Zreitan:
That doesn't seem right. For everyone I know, lower refresh rate means more strain on the eyes. Anything below 75Hz on a CRT gives me a headache. On LCDs, I can't really tell the difference between different refresh rates. Response times I can tell the difference in, but not in the sense that I see 8ms being better than 12. It's more "this screen doesn't blur, but that screen does blur." - swizzlestick, on 10/12/2007, -0/+1I just set my CRT to 60Hz and turned off all the lights, and the flickering is still very visible. It's sorta like those stop lights that have a small flash tube that blinks every few seconds when the light is red, to draw your attention. Even when not looking at the screen, my attention is diverted to it because through my peripheral vision the flickering is being detected as motion.
- inactive, on 10/12/2007, -0/+1but we still don't see in pixels. you just agreed to it.
- mercurysquad, on 10/12/2007, -0/+1The difference between LCD and CRT refresh rate is that in a CRT it's a literal refresh rate, while on an LCD, it's just the rate at which the screen contents are updated. Once a change is made - it stays like that on an LCD, while on a CRT, change-or-no-change, the image has to be refreshed every x times a second.
On an LCD, the response time is more important - the time it takes for a pixel to change its color.
Kinda like, with CRTs you see "flicker" (on the whole screen) while with LCDs you see "smudging" (in specific parts which are being updated) - Eccles, on 10/12/2007, -0/+1@ mercurysquad, you're not right either.
The limiting factor is *not* the graphics card, or this article wouldn't be talking about fixing LCDs; you would just turn the refresh rate up on your card. Most modern cards can handle the rates mentioned in this article at typical LCD resolutions.
The pixel response time is part of the limiting factor. The key limiting factor, however, is the circuitry in the LCD panel; it's simply not designed to work with a higher rate. Back when 16 ms response rates were more common, this made sense: 16 ms * 60 = .96 seconds, so the panel couldn't go much faster. With 8 ms pixel responses, however, 125 changes/second are possible, and thus you can upgrade the circuitry of the panel. - mercurysquad, on 10/12/2007, -0/+1Sorry chucker, LCDs do have a refresh rate limited by the graphic adapter they are connected to, and the pixel response time. Thus there is a maximum limit to the number of times the screen contents can be refreshed. And 60Hz happens to be that typical maximum (at least on most laptops).
- Mugsleymug, on 10/12/2007, -0/+1mentioning the hocky puck thing, i notice my mouse arrow dissapears against certain high contrasts when I'm doing some photoshopping. I dunno what my refreshrate is, but i have a dell insprion 9300 with 17" at 1920x1200 (i think), so whatever it is, I notice small high contrast objects dissapear of my monitor too.
- chucker, on 10/12/2007, -0/+1I did. I responded to the assertion that "typical LCDs have a 60 Hertz rate". They don't. They don't have a rate at all.
- cTTbLaKeMAn, on 10/12/2007, -0/+0thats good cause it wont give you a splitting headache after several hours.
- Zreitan, on 10/12/2007, -2/+2ive tried running things at 120-100 hertz and its really hard to look at a screen like that..gives me a headache!
- zeppo, on 10/12/2007, -1/+1I got a samsung 205BW 20inch LCD widescreen 1680x1050 so for HD sources your only option is 1280x720. Anyway when I compared to my big screen Toshiba 46H84 to colors looked much sharper on the LCD and I didn't notice any blur so maybe from the XX5BW models they use that technology. This is my first LCD monitor I could never use them before because they made my eyes hurt or just looked weird. The only problem is with this monitor its not big enough and you end up wanting more of them heh
- Topher06, on 10/12/2007, -0/+0There are only like 3 makers of LCD substrates, and Sony isn't one of them.
But its not the quality of the LCD substrate that matters, but the electronics wrapped around it. The difference between cheap-ass LCD TV's and more expensive ones is how the video signal is processed. For instance, on cheap LCD TV's, standard def signals tend to be poorly upscaled and so anything but HDTV content looks like crap, more expensive TV's use higher performing video processing that does a much better job interpolating lower resolution sources and converting them to high res output.
For the time being, investing more money into an LCD TV will result in better quality. As the electronics used gets cheaper and more ubiquitous, then buying cheap off-brands won't matter as much. - GliTCH82, on 10/12/2007, -1/+1It's about damn time
- inactive, on 10/12/2007, -2/+2The first time I really got a good look at an LCD TV was recetnyl actually. (Yeah, I know. I mean, I've seen them for moitors, but not for TVs) I never realized how bad this blur thing was until I watched a hockey game. The puck would just disappear sometimes on hard shots.
The question I have about this solution is, how does it affect the life expectancy of the TV? - chucker, on 10/12/2007, -3/+2"A new technology refreshes TV images at 120 to 100 hertz, or 120 to 100 times a second, versus the 60 hertz rate of typical LCDs."
So according to c|net, LCDs have a refresh rate now. Learn something new every day, I guess? Not.
The article is about lowering response times and improving the backlight, not about reaching higher refresh rates -- an LCD doesn't "refresh". - dimension128, on 10/12/2007, -6/+4Wow Ive heard people say this before, but never in such a high frequency. I'm sorry to hurt your assumptions people, but either my eyes are not 'human eyes' or your wrong.
Remember the SP, LP, etc settings for vcr's? I could tell the difference.
Playing a videogame:
15-30 fps I can see the difference.
30-60 fps, I can tell the difference.
60-120 Yes I can tell the difference.
LCD-TV's, yes there is a real problem with motion. I'm sorry if you can not see it, but that doesn't change the fact that other people can.
Btw, I can also hear the high pitched tone a TV makes when its on, and I know a lot of other people who can to. But people still say that humans cant hear that, go figure. - animefx, on 10/12/2007, -4/+2Samsung has some nice sets, but if you look closely at thier LCDs they seem to suffer a fair amount of "mosquito". If you want to get a really nice and affordable LCD now, I would recommend the latest 32" Sharp Aquos... When calibrated correctly they are incredible! If your lucky you can find one online for around $899.
Personally, I will wait until mid to late 2007 and waste money I don't have on a 37-46 inch 1080p with hdmi 1.3, under 6 ms response time, and the new chip they discuss in this article.
No one said being a geek was cheap... - gblackbox, on 10/12/2007, -2/+0"Unlike a traditional CRT monitor, an LCD monitor does not have an electron gun or a tube with phosphors. It is made up of an array of liquid crystals placed between two pieces of polarized glass. Light is then sent from the back of the glass, and the shape of the crystals are controlled in such a way as to alter the light which passes through this glass and comes out through the screen. *****As such, an LCD screen does not have to refresh the entire screen constantly like a CRT monitor does just to maintain an image.***** Whenever an image alters on an LCD screen, a command is sent to the relevant liquid crystals in the array to change shape as required. How quickly they can do this is called the Response Time of the LCD monitor.
As we've seen in the Refresh Rate setting, CRT monitors can flicker because of the way they refresh the screen. *****An LCD monitor on the other hand does not have to go through a repetitive cycle of constantly refreshing itself many times per second like a CRT monitor.***** This is because it has no phosphors to constantly light up; instead the liquid crystals will remain open to continuously display an image for as long as required. An LCD monitor does not show a black screen when inactive, or in between updating portions of the screen; it does not fluctuate in brightness. So looking at an image on an LCD monitor is like looking at an image on a piece of paper. The concept of refresh rate does not apply in the same way, at least for the purposes of flickering.
However just like a CRT is physically restricted by how fast the electron gun can redraw the screen each second, an LCD has a physical limitation of its own: the time taken for individual liquid crystals to twist and untwist in response to any changing images it is fed. This Response Time effectively measures how quickly the on screen image can be fully 'refreshed' (minus flickering of course) with a new image. Response time is correctly measured as the total amount of time taken for a pixel on an LCD screen to go from full black to full white and then back again to full black, measured in milliseconds (ms).
So if an LCD monitor doesn't refresh itself many times a second, why does an LCD monitor still require a particular refresh rate setting in Windows XP? We previously discussed the fact that refresh rates are something only a CRT monitor needs because of the way it physically operates. Well it appears that LCD monitors need to emulate a refresh rate in Windows XP primarily for compatibility purposes with games and hardware. Games, Windows XP and your graphics card are all still designed around composing individual frames in the frame buffer, and sending these whole frames to your monitor one by one, with the timing for buffer flipping typically based on Vertical Blank Intervals - all things which were originally required for CRT monitors. Therefore LCD panels have to try to operate on the same basis, despite the fact that they don't have the same physical limitations of a CRT."
http://www.tweakguides.com/Graphics_8.html - inactive, on 10/12/2007, -4/+2can eyes even see that speed?
- Mugsleymug, on 10/12/2007, -4/+2@illit
i dont know much about LCDs but I thought it was something simmilar because the HZ on my laptop screen says 0hz - ahhell, on 10/12/2007, -4/+1I always hated the blurring on LCDs. It's part of the reason that refuse to buy one.
The fixed resolution is another. -
Show 51 - 57 of 57 discussions
Check out the new & improved 
© Digg Inc. 2009
— Content created and posted by Digg users is