The Power of Pictures by Kieron Seth first saw true HD pictures years ago at IBC. OpTex had a camera focusing on some beautifully lit fruit. The image on the screen was extraordinary, hypnotising. Leap forward a decade and Amsterdam brought Europe its first taste of Ultra High Definition Television - not 720p, not 1080i, but 4320p. The enveloping cinematic pictures and the embrace of 22.2 channel sound were overwhelming. My colleague was quite emotional, and for me, despite being in this high-tech business bazaar, this was a memorable moment. This is the power of television. To date no streamed video has yet had the same impact on me. The limitations of bandwidth mean that today, video over IP is a strangled, muffled affair. To give it credit, streaming is in its infancy. H.264 was standardised in only 2003. YouTube only began in 2005. The iPlayer's history goes back less than 3 years. And on reflection, these services have made major leaps in that time, rolling out 720p and 1080p, adaptive streaming, 16:9 and even 3D. So maybe my dissatisfaction is a typical 21st century need for instant gratification. Sadly the video production community can't do much to change the country's broadband infrastructure. Nor do I know of any magic codec that will be able to deliver real HDTV at 1mb/s. My old house is a squash and a squeeze It's an inescapable fact that video production creates large data files, even if modern cameras squeeze the data as much as broadcasters I will allow. Camera compressors essentially save one frame - the key - and intelligently encode information that changes from frame to frame, rather than capturing all the information from every frame. When confronted with fast edits, complex and changing backgrounds, moving cameras, every pixel of these intermediate frames must also be saved. But for a talking head, only a few pixels will change, so the file will compress well. Failing to understand compression has certainly filled the Internet with videos that are nothing more than a pixellated mess. Production specialists have developed a number of effective ways of shooting that produce streaming-friendly files. The wise Christina Fox (www. urbanfox.tv) writes on her website: "For minimal file size, the ideal subject is probably a talking head against a bland background in a noise free studio." She advises that the rich, vibrant fast action scenes a television broadcaster can get away with are "enough to make a codec melt." By taking Christina's advice, the camera can be coaxed to capture more of the important data - the subject - and less of the backdrop. The effect is to create videos where the focus of the film is a sharp, strong and well defined image that stands out clearly against a plain background. With the codec untroubled by irrelevant detail behind the subject, there will be more `bits' for the all-important subject of the video. A camera revolution... for the Internet? Perhaps we can now go a step further... Large sensor camcorders have caused an upheaval in the video, TV and film worlds. The Canon 5D, ARRI's Alexa, Sony's F3 and Panasonic's AF-101 are all changing the way programme makers approach their work. Camera operators are able to use the shallow depth of field and low light performance of these models to create a stunning cinematic look that had traditionally been reserved for 35mm film cameras and the most exclusive digital models. Some will argue that this technique is becoming over-used and others would contend that maximising the `bokeh' of a scene is alien to how the eye sees. However, it is widely adopted both as an artistic approach and as a way of fixing the viewer's attention on the subject matter for everything from news interviews to natural history films. So what has this got to do with streaming? "We've had this notion for a while now, that the shallow depth of field that these new cameras can produce may just be what streaming has been waiting for. A tight focus on the subject with the other elements of the frame blurred should, in theory, produce beautiful, smooth-playing files." Argues Barry Bassett, MD of VMI Camera Hire. Richard Payne, camera specialist with Holdan concurs: "We've seen lots of examples of great films being posted on the Internet using the 101 and the Alexa. But we were keen to find out whether sensor size makes a tangible difference when it comes to streaming video. Or is the picture quality improvement actually down to the production values of the shoot and superior encoding." Testing Times In controlled conditions selected to mimic a typical chaotic backdrop (and to escape the blustery weather), the tests were performed: two cameras, fixed to tripods, recording the same format, to the same solid state field recorder. The Panasonic AG-AF101's 4/3rds MOS (an area of 225mm2) sensor is compared against the Panasonic AJ-HPX-171E's 1/3" CCD (an area of 17.3mm2). The AF101 was equipped first with an Angenieux 15-40 Optimo Zoom T2.6 and then a 66 | TV-BAY MAGAZINE