TV-BAY Magazine

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Shooting the 4K TV look N by Bob Pank ot unexpectedly IBC was full of buzz and products for 4K – the new image format for television. This is generally taken to be a 2x2 version of HDTV’s 1920 x 1080, i.e. defining a 3840 x 2160 pixel picture. But there is nothing new about big pictures like this. Back in late 2004 a draft of the Digital Cinema Initiatives (DCI) Digital Cinema System Specification included the two picture sizes of 2048 x 1080 and 4096 x 2160 pixels – referred to as 2K and 4K. So, give or take a few pixels, 4K sized images are nothing new; it’s just that now we are talking about television rather than cinema where it is already well established. 48 | TV-BAY MAGAZINE: ISSUE 82 OCTOBER 2013 In the years leading up to the DCI Specification there was an ongoing debate about the number of pixels needed to render the full definition of a 35mm film frame. After all, the new medium must be at least as good as the one it replaces. It could be shown that a 4K scan of a 35mm original camera negative frame (a full frame (biggest possible) image being 24.92 x 18.67mm, Cinemascope 21.95 x 18.60mm) looked sharper than a 2K one. But then, after the film had been optically copied via interpositives and internegatives, and then distributed on release prints that went to the cinemas the resolution was generally significantly lower than 2K. So DCI images at 2K showed an immediate improvement in the cinemas and the format was used in virtually all digital cinemas... for a few years. But 4K was not forgotten. Many film movies were scanned at 4K resolution and the format became available on digital cameras. The provision of transport/networks, compression, storage and other technologies continued to develop and 4K looked less and less of a burden. Then it started to be projected in digital cinemas. The result provides a sharper, clearer image for the audience to appreciate on the big screen. Now technology allows 4K, a picture that looks great in cinemas, to be viewed in homes as 4KTV. And yes, you will need a big screen to fully appreciate it! Changing the resolution of the images has knock-on effects. Digital cameras for movies were required to provide the ‘film look’. I’m not sure if this included scratches, dust, weaves and grain but to many it meant being able to use a shallow depth of focus – especially on close-ups. And so it was that ‘film sized’ imagers became de rigueur for digital movie cameras (it also applies to the HDSLR range of cameras that again have sensors at or around the 35mm film size). That, at least, can provide a part of the established ‘film look’ but does it belong in the TV look? No it does not. Such shots may be fine for drama in cinemas, which is mostly what they show, and for drama on TV, but news and, especially sport, as well as other TV genres generally much prefer a deep field of focus. So, for example, most or all of the players on a football pitch can be in focus at the same time – pretty much as it would appear if you were there. In most cases it can be argued that the shallow field of focus is not natural and the deep is more like our normal perception. So far 4K camera technology still seems to be stuck in movie mode while a new breed of 4K cameras for TV needs to be based on the much smaller imaging sensors at around the half-inch diagonal size, as is widely used in TV today. Other knock-on benefits would be a resulting reduction of the size of the camera body and lens assembly, which would be very welcome – especially on location shoots and OBs. Manufacturers have been slow off the mark, promoting superb massive