article.php

As reported last issue, Inition is one of three UK companies, along with Axis and Can Communicate, which have come together to form a comprehensive team for delivering high quality stereo 3D to the marketplace. Branded under the name The3DFirm their first collaborative project was a recent promotional shoot for the re-launch of Reebok’s sponsorship deal for the Commonwealth lightweight boxing champion, Amir Khan. The five-minute piece was produced by Can Communicate, with cameras supplied by Axis Hire and Inition providing the on-set stereoscopic supervision. Shot on location in Amir Khan’s new gym, the film features some great live action stereo 3D footage of the Bolton boxer in training; punching to camera, hitting speed balls and punch bags, doing sit-ups and working in the ring with his trainer – as well as some real Rocky-like moments running in the park.

The screening took place at the National Film Theatre on London’s Southbank using Inition’s Duality projection system to an appreciative audience of sports and national press. The short film really demonstrates the possibilities for sports broadcast, and is a far cry from the normal gimmick shots usually associated with the stereo 3D format. More of an enhanced experience rather than a tacky add-on. The film will eventually be made available to view on line in an anaglyph format and a cut-down version for a 3D digital cinema ad.

More recently, The3DFirm has been breaking some entirely new ground with the world’s first live stereo 3D transmission of an international sports event. This will involve the BBC’s Six Nations rugby coverage of Scotland versus England in 3D HDTV. As this issue of Showreel goes to press, The3DFirm is gearing up for a live broadcast via satellite from Murrayfield Stadium in Edinburgh, Scotland to the Riverside Studios in Hammersmith, London on the 8 March 2008.

As usual, Inition will be on location to supervise the stereo 3D acquisition and transmission. As Andy Millns explains: “We’re working with BBC Outside Broadcast to cover the Six Nations match between England and Scotland, which will be transmitted live in 3D. We’ve been carrying out tests with them for some months, and we know that we can send two cameras up to the satellite and back down again in sync, and it all works seamlessly. There will be three camera positions, with six Sony HDW900 cameras.”

A similar national event in the US transmitted the NBA finals to three large screens in front of an audience of 14,000 people. “I think they were proving the model,” explains Andy Millns. “That you could do it with a live event and a live crowd; and that you could potentially make money out of it. Because the audience behaved like a normal crowd – they all bought drinks and T-shirts. Obviously to do a live 3D broadcast to one venue is not necessarily going to be profitable, but once you’ve got the acquisition side sorted you can beam it to however many 3D enabled venues and cinemas you want around the world.”

Inition has developed a camera rig called the 3DVidRig. Originally built for the low-end market, for cameras such as the Sony HVR-Z1 and A1, the company has now redeveloped the rig for use with much bigger broadcast cameras, as well as 2K and 4K cameras, such as the Red and the Silicon Imaging camera. Like most rigs, the 3DVidRig places two cameras side by side on a bar (the ProStereoMount) that facilitates both parallel and convergent shooting. A Stereo LANC controller keeps budget cameras in sync and the rig allows for vertical adjustments too. “That rig has evolved over several years,” says Andy Millns. “It’s about the fourth incarnation of it. The important thing for us is continuous controls. The way we work is not so much about just using the math to calculate the 3D; it’s more about using a suitable live preview system to make judgments live to optimize the 3D.”

There are several methods of previewing stereo images live, but what’s important is to be able to recognize differences between the left and right image. “We have various systems,” says Andy Millns. “With HDV cameras we can take a live firewire from each camera to laptop and combine them as an anaglyph image. We have other systems that are based on video where we can take two composite or component signals out and mix them with a crossfade and horizontal or vertical wipe. Then with a trained eye you can use any monitor. In a studio shoot you could use a small projection system. Anaglyph is very useful because you can view it on any normal monitor. You can take your glasses off and see the relationship of the two images, which is the most important thing. If you’ve just got a 3D system that allows you to see in 3D, for example a head-mounted display, you can look at it and go ‘Oh it looks wrong, it’s hurting my eyes!’ But you won’t know why. What you really need to see is just a left and a right image overlaid on top of each other. So if you’ve got a 50-50 mix or you can crossfade from one to the other, you can see clearly the relationship between the left eye and right eye. Instantly you can tell if one of the cameras has got a slight roll on it or if the exposure is different or if you have a vertical misalignment between the two cameras. A 3D monitor wouldn’t necessarily tell you why.”

The combination of live preview and the ability for the 3DVidRig to converge the cameras means that the stereo 3D effect can be manipulated to lesser or greater degrees while shooting live. “The great advantage of a rig like that is you can look at it and say, ‘right that’s looking good, but we could actually push the 3D little bit more’,” explains Andy. “And you can really optimize the amount of 3D you can get out of a scene. You can also look at the shots and the composition and see how that affects the 3D, which you couldn’t do by just doing the math. The other great thing about having a live 3D preview is for clients. They put on the glasses and they say ‘Wow!’ and instantly buy into to what’s going on and get really excited about it. It’s the same for the talent as well. For example, when we were doing the Amir Khan shoot we had a live preview on a Planar monitor, which is two LCD monitors with a central mirror. It was fantastic because it got him on board as soon as he saw it. And when his manager saw it and his trainer saw it, they got what it was all about, and that really helps – as well as giving us a very powerful tool to allow us to exploit 3D to the maximum.”

Parallel vs convergent

Which approach is best parallel or convergent? “Well, basically there are good arguments for both,” says Andy Millns. “To get the best results, I’d say do it parallel, but there’s a few caveats to that. If you’re shooting parallel, everything is out of the screen and to shift it back in you lose some of the frame, because you have to zoom in to fill it up again. So if resolution is an issue and you’ve got a problem with throwing away some of the frame, then that’s an argument for shooting toed-in or convergent. If you’re working with a basic live preview systems, without the ability to shift parallax live, and you don’t toe-in the cameras, you’re going to have difficulty 3D monitoring – partly because it’s all going to be pushed out of the screen, and anything breaking the frame will look wrong, so you can’t really tell what you’re getting. This can be fixed with more sophisticated preview systems we are using with live parallax shift. The disadvantage of shooting toed-in, depending on how much you toe-in and how big your destination screen is, is that keystoning issues can be a problem. If you’re looking at it on a small screen, keystoning errors in the sides of the frame may not matter – especially if you focus in on the subject in the center of the frame, you don’t really care if there are small vertical offsets. But if you blow that up to an IMAX screen it will all of a sudden become a huge problem. I think there were a lot of problems like that in Ghosts of the Abyss; some huge vertical parallax errors. Obviously they were shooting under very difficult conditions under the ocean. But you can fix those keystone errors in post. So, I would say that, theoretically, it’s always best to try and shoot parallel, especially with today’s 2K-plus resolution cameras. You get bang on alignment and none of these vertical parallax errors, but for practical reasons it’s sometimes better to shoot convergent.”

There is no denying that after many announcements, press events and some big name posturing around the stereo 3D format, we are finally seeing the promised explosion in technological development and content. It would appear that the time of waiting is finally over. But what will be the future developments in stereo 3D acquisition?

“I think what’s important in 3D filmmaking,” says Andy Millns, “is to minimize that amount of time that the 3D guys are in there fiddling with the rig. That’s what we are trying to get towards. For the Six Nations rugby event, we are using a new wireless 3D video monitoring system that we have developed in house. It’s known as FarView3D. This will allow us to wirelessly view any stereoscopic camera system on a laptop or tablet in anaglyph mode. The idea is that we can monitor 3D at a distance without interfering with the camera operator and set up the 3D rig without having to attach local 3D monitors with all the associated cables. We will be able to switch between monitoring the three camera positions very quickly via the software interface on the laptop.

“I can’t imagine there being a new widespread 3D cinema technology within the next decade, so we’re going to be stuck with the current technology for at least ten years. The most important problems we have to deal with now are improving the acquisition systems and workflow. The sort of advances we’re looking for in the near future are going to be motorized rigs that can take a range of cameras, but which would also have integrated lens control. So you have one control that would operate focus, iris, zoom, inter-axial distance and convergence, and that could also be programmed to change throughout a shot. There’s a lot of activity in rigs development at the moment, especially motorized rigs and different configurations for beam-splitter rigs. We’re working on rigs with P+S Technik in Germany, the distributors of the Silicon Imaging camera, and also Mo-Sys here in the UK to develop a 3D rig integrated with its motion control system. The other side of things is the larger broadcast camera rigs. For live events, it’s very important that we can work with the existing broadcast camera infrastructure rather that bringing in all our own camera equipment. So we’re working on another rig which would be for heavier broadcast cameras. It’s all happening very quickly at the moment, and The3DFirm is a way of pooling our resources to cope with the demand. These are very exciting times!”

A sporting spectacle

David Valentine.