Originally featured on BroadcastEngineering.com
EBU calls for higher TV frame rates beyond HD
As if higher HD resolutions were not enough, providers of network capacity such as Telcos and satellite operators will have to cope with elevated frame rates as well if the EBU has its way.
The EBU has been arguing that higher HD resolutions will require a corresponding increase in frame rate to realize the full potential improvement in user experience. To that point, EBU deputy director of technology David Wood has been busy making the case for higher frame rates with some quite convincing demonstrations. In one of them, he turns a bicycle upside down and uses the pedals to spin the back wheel fast. At current TV frame rates up 50fps or 60fps, the back wheel appears to be moving backwards on the TV — quite different from how it looks to someone present at the scene. But, at a higher frame rate, the bicycle wheel appears to move just as it does to the naked eye.
This ability to capture continuous fast movement more accurately is one of two reasons Wood believes broadcasters will move to higher frame rates. The other is more subtle in that the brain, in reality, samples the world around us in 3-D at varying rates depending on the situation, and that, even at 50fps, there will be some occasions when it will therefore take in the same frame twice, providing a slightly distorted image of reality even when there is little movement.
Wood is unsure what frame rates will eventually prevail, but suggests it will be at least 100fps, and perhaps as much as 300fps or even 600fps. Critics contend that fast-moving bicycle wheels are only usually seen in the background of a TV picture, and that for nearly all action 50fps is fast enough. Another counter argument has emerged in the wake of Peter Jackson’s recently released Hobbit movie, which was shot at 48fps rather than the usual 24fps. Some early viewers have reported, almost perversely, that the higher frame rate makes the action look “too real” when the film is supposed to be a fantasy.
Not all movies are fantasies, of course, but it is true that cinema, by persisting with the low frame rate of 24fps, has created a viewing experience that is rather languid and a bit jerky in the case of fast action. Yet, bandwidth considerations rather than movie diehards are more likely to arrest progress towards higher frame rates both for the cinema and TV, although just as many people love old black and white films and music on vinyl, so there will be a constituency for continuing to watch at 24fps.