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How they shot the world’s When it was “taken” late last year, the photo above of the city of Seville, Spain, was a world record at 111 gigapixels. If printed out, it would be bigger than two football fields. And you can zoom in to show amazing detail. But shooting such a photo was no mean feat . . . L est we be accused of the bearers of old news, this photo is no longer the world record holder – that honour (currently!) goes to a similar type of photo of Shanghai, China, at 120 gigapixels. We thought the story of the Seville photo was really interesting and if SILICON CHIP readers wanted to do the same thing for their fair city, it will give you some idea of the trials and tribulations involved! Before we get too far into the story, perhaps you’d like to have a look at the photo (and have a play). You’ll find it at www.sevilla111.com/default–en.htm OK, back again? I’ll bet you just wasted an hour or so, right? Sevila 111 high-speed lift to the top, they had to carry everything up 16 stories – and of course, back down again. The camera gear A Canon 5D MkII camera was used along with an effective 800mm lens (400mm plus 2:1 extender). The plan was to use an aperture of f16 and a shutter speed of 1/800S (ISO800). These setting resulted in a very satisfactory tonal range over the entire area. A robot, built by the photographers, was used to move the camera to its next shooting position and open the shutter. Initially, aiming and shooting took about 4.8 seconds per image. On the first test, they shot about 2000 pictures, covering 160° . But they soon ran into a couple of major hurdles. First was the weather itself – with the sun going behind clouds or sudden rainstorms resulting in vastly different exposures. More important, though, was the wind – which while virtually non-existent at river level created severe vibration and shaking at camera level. And an 800mm lens certainly exacerbates the problem. A third factor was the temperature itself – Seville in summer is quite a warm place, and the heat haze became a real problem. The result was to postpone the shoot until after the summer. The photographers, José Manuel Dominguez and Pablo Pompa, wanted to capture the magic and charm of their home city and make it available for people around the world. The result of several months of work was, when completed, the largest panoramic photograph in the world – 613,376 by 181,248 pixels. The project was commenced in March 2010 with the selection of a suitable site from which to photograph the city. After examining and rejecting several sites, the Torre Schindler (a 60m-high observation tower on the banks of the Guadalquivir River) was chosen. As well as offering a solid platform on which to mount Moving targets! Initially, the goal was to shoot a world-record 60 gigapixel the camera gear, it offered a 290° view of the city from notimage but during the wait, others had achieved 70 gigapixel. too-far away from the centre of the city. The Seville team then changed their plans to The downside was that the tower was beby Ross Tester achieve a 100+ gigapixel image. In the last ing refurbished at the time, so instead of a 28  Silicon Chip siliconchip.com.au largest photograph: 111GP days of September 2010 they shot about 14,000 individual frames – all told, they had shot 35,000 frames since April! Computing power To “stitch” together the images requires a computer with a lot of grunt. In the end, their PC had two 6-core Xeon processors, 40 gigabytes of RAM and an 8TB hard disk drive. They chose a software package which they were already familiar with, Autopano Giga. Editing To achieve the 100+ gigabyte target, they selected 9,750 images, 65 rows each of 150 images. Initially sorting was one using a .jpg image, rather than the RAW format which would have taken much more time. They also had to discard all repeated images and images with incomplete elements, such as parts of people and cars. It took a full week to copy, review and sort all the images. Fortunately, only the images taken in late afternoon needed editing to match the others. Problem! They then ran into a major problem: the Autopano Giga 2.0 software simply wasn’t powerful enough to handle 9750 images – in fact, it had a 5000 image limit. Fortunately, about this time the beta version (2.5) was available which had a 10,000 image capability. It also had a couple of welcome new features such as a haze filter and was significantly faster. But it was also buggy (being a beta) which caused lockups and crashes. Just when they were about to throw the whole project away, a new version came out which didn’t have the bugs. Final rendering In mid November 2010 the final rendering of the files was commenced. There were three files, each one taking about 32 hours each. It took a whole week to render, then correct any rendering errors and finally blur people’s faces and car number plates to avoid identification. siliconchip.com.au Viewing KRpano software was used as a viewer because it works with Flash and is therefore compatible with most web browsers. This software also supports several interactive operations, which can be seen in the final image. The resulting panorama consists of 140,000 small images which are displayed on the browser as required. Zooming in is possible to extraordinary level and moving back and forward over the panorama is also very smooth. Psst! Want to shoot your own panorama? W h i l e r e s e a rc hing this story (honest, boss!) we came across this “Gigapan Epic PRO”, a robotic camera mount which appears to do the same type of multiple-image photography as used for the above pic. Strong enough to take a DSLR camera up to 4.5kg, the Epic PRO will take hundreds or thousands of detailed photos for one intricate Gigapan. Coupled with the new Gigapan Stitch software, these photos are efficiently combined into a seamless panorama and uploaded to gigapan.com, where you can view, share and explore them. The Gigapan Epic PRO offers a 360° panorama with +65° to -90° tilt range, to take into account even the most challenging mounting positions. Steps are 0.04°/step for tilt, and 0.12°/step for pan. It operates from rechargeable batteries (battery pack and charger are included. The Gigapan Epic PRO sells for $US895.00 More information? www.gigapansystems.com SC September 2011  29