If you are out there looking for an HDTV, then you’ve probably heard quite a lot about “speed.” When different commercials and reviews speak about how fast HDTV is, they are talking about the display’s refresh rate, or in less technical words, how often it changes the picture. TVs and movies don’t actually show motion picture so much as hundreds of frames per second. This means, the faster the refresh rate, the better the resolution on the HDTV right? More frames mean smoother visual appearance, right? In theory and for marketing purposes this may be true; but in practical sense, it’s not so much.
Pull Down and Film-Video Dance
To get answers to these questions, you first need to understand two important aspects about video. First of all, you simply cannot add any details that are beyond what is already within the source footage. Secondly, the source footage is never higher than 60Hz. When watching a movie in Blu-ray, it is a 1080 picture at 60hz. This Blu-ray disc displays 60 interlaced frames at resolutions of 1,929 by 1,080 per second of video motion.
For movies recorded on film, original footage is 24 frames per second, up-converted to 30 frames through a certain process referred to as 2:3 pull-down. This process redistributes source frames so that they can be spread throughout 30 and not 24 frames per second. These frames are then combined and shuffled (interlaced) to 60 frames per second in order to match 60Hz refresh rates found in the majority of television sets that you buy in the market. In the case of 1080p60 TVs, frames are pulled down to 60 frames per second, and players and HDTVs skip interlacing steps.
This can be best regarded as a time-honored tradition, due that reason that American TVs have actually displayed 30 frames per second and performed at 60Hz since immemorial time. This is not really a major problem because between frame pull-down and interlacing, the process doesn’t intend on adding any information to the motion picture.
It is rather converting it to perform on the TV, because otherwise it wouldn’t work. 1080p60 is currently the highest standard for HDTVs, and there isn’t any higher frame rate or resolution on the market. In fact, the majority of movies on Blu-ray actually turn down the frame rate and display at 1,920-by-1080 or 1080p24 video at 24 frames per second, to enable the footage appear as close to the film as much as possible. The different refresh rate ever-increasing technologies in HDTVs are destroying that effect.
Higher Refresh Rates
If an HDTVs refresh rate goes exceeds the rate of the content you are watching, it begins performing a number of tricks to produce higher frame rates. It interrupts new frames between frames transmitted to the display at 60fps for film footage via a separate pull-down process, and the HDTV fills up the spaces by creating the best “middle” frames to plug in the cracks. The new frames are created processing and combining the data of the frames around them, and creating images that will make the HDTV think that it should draw between the images as it is told to draw by whatever the media it is using. In this instance, you are looking at more individualized pictures as the screen draws them, but the pictures were not on the Blu-ray disc or TV signal which the signal will be receiving; the HDTV is creating such additional pictures on its own.
Good for Games
When flat panel HDTVs rolled into motion some years back, they had a common problem, which was motion blur. LCDs especially were prone to displaying distinct blurriness during quick movements because of the afterimage (ghosting), which remains after an image on the screen changes. LCD technology has changed a lot of the past couple of years, and now motion blur and ghosting have been eliminated.
Even without the presence of motion blur or ghosting, you may notice tearing or choppiness ( an effect that occurs when part of the image appears to hanging behind what’s on the entire screen for the moment). This normally noticeable during sports and video games, or other content that has horizontal and fast panning of the camera. In such a case, higher refresh rates modes can do a lot to help.
What About 4K?
Ultra high definition TV (UHD or 4K) is still its infancy, and although you can buy a 4K HDTV you will at some stage experience problems in getting an appreciable amount of media for it. The HDMI 2.0 standard only has just made 60 frames per second 4K video a constant prospect possibility for different devices, and a lot of processing is already involved on displaying higher 3,840 by 2,160 resolution that interruption and adding frames to allow for smoother action has not been of major concern for HDTV makers yet. In general, if you are interested in a 4K screen, you shouldn’t expect it to break for a while.
Are Super-Quick Refresh Rates Worth It?
Improved refresh rates can go very far. Although 120Hz refresh rates that are seen on many midrange HDTVs do work well, you shouldn’t expect to see much performance enhancement from 240Hz refresh rates or, for different plasma TVs, 600Hz. Importantly however, is to know when and how to switch turn these improved refresh rates off, and use the default 60 Hz film that comes with most sets.