Arri News, Headline

3D Dinosaur Hunting with the 235

Thursday August 30th 2007

After several years of expecting digital image capture to overtake our film based design for smaller 3D cameras, I began to realize that digital technologies were giving birth to new directions in some respects, but falling short in others – namely rapid high volume onboard storage.

Therefore William White and myself (both of the 3D Camera Company) decided to work with ARRI on the development of a super flexible and super lightweight 3D rig, utilizing two ARRIFLEX 235 cameras, Ultra Prime lenses and the ARRI Wireless Remote System for the IMAX© movie Dinosaurs Alive! and various further IMAX projects. Using small and lightweight 35 mm film cameras to capture images for IMAX 3D projection provided us with unprecedented flexibility and unique shooting angles so that we didn’t only use the rig for 10% of Dinosaur Alive! as originally planned, but for nearly half of the film.

3D cinematography is principally a wide-angle medium and not difficult to put on film. With the right tools and following some simple guidelines any experienced director and cinematographer can produce fully immersive and exciting images for all types of 3D story telling. Arguably the most breathtaking 3D imagery can currently be achieved in the IMAX 3Dâ„¢ format. Unfortunately, the 225 pound (102 Kg) IMAX Solido 3D camera makes it difficult to get some shots, and prohibits the use of many shooting techniques that are commonplace in 35 mm feature film production, including handheld shooting, Steadicam, long cranes, gyro-stabilized heads, car mounts, etc. In addition, the lenses available are 25 years old, have a widest aperture of T4.5 and show various types of distortion, an unwelcome drawback especially for special effects work.

I have been approached many times in recent years by producers of large format films that want smaller, lighter 3D cameras, with faster, distortion-free lenses and greater depth of field to complement the breathtaking imagery of the IMAX 3Dâ„¢ Solido camera system. Everyone wants to find ways to get the real money shots by getting 3D images in unusual places and from unique angles. In the past, I had designed several schematic versions of cameras to achieve these objectives. I had even invented a new shooting format that interlaced Vistavision stereo images at the perfect spacing for the human eye. However, I was concerned with the emergence of digital capture, so none of these cameras have been build.

After having waited for several years for digital cameras that could be used to get 3D images I realized that it would still be some time until they could be used in this way. The real accomplishment of digital technology in the past five to ten years has been the ability to digitally enhance the already exceptional film negative – a process known as the Digital Intermediate. It is, for instance, possible to scan and digitally "up-res" images shot on 4 perforation/35 mm film to the 15 perforation/70 mm IMAX projection format. The result can be of sufficient quality that the difference between the 35 and 65 mm originated material is very difficult to see. This capability allowed the development of the DMRâ„¢ (digital re-mastering) process, a technology developed by IMAX to make it possible for any 35 mm film to be transformed into the image and sound quality of an IMAX movie. DMRâ„¢ is used to show first run feature films on the giant IMAX screens. I realized that the same technology could also be used to shoot 3D material with 35 mm film cameras to be intercut with material generated on 65 mm film.

In April of 2006, with several up-coming IMAX films to shoot, my partner William White and I commissioned ARRI to help us modify two ARRIFLEX 235 cameras to create a small and lightweight Super 35 mm 3D System. We wanted to shoot parallel stereography without mirrors and use the most distortion free lenses in the world – the ARR/Zeiss Ultra Primes – to our advantage. With the IMAX movie Dinosaurs Alive! (originally called Dinosaur Hunters) in hot pursuit of equipment, we had only three months to design a special base plate and to go shopping for a completely matched set of 235 cameras and identically matched pairs of Ultra Primes.
(from left to rigt) Key Grip Christopher Tate, the IMAX Solido 3D camera and Master Rigger Claude Fortin on location in Mongolia.

Sebastien Laffoux at ARRI Canada spearheaded the effort together with Michael Haubmann from ARRI Austria, who coordinated a very enthusiastic team of engineers. We needed synchronized master/slave camera movements, synchronous focus, iris and zoom controls and an extra convergence control channel. Plus, to optimize normal stereo vision we needed to get the Ultra Prime lenses as close to each other as possible. The 235 camera is a natural for this, as it is very small and lightweight, but still contains all the modern features we needed. The engineers at ARRI removed one of the video assist control panels and mounted it on top of the camera so we could get the cameras as close to each other as possible.

For perfect synchronization, they installed a small electronics board into the camera, right underneath the blind connector on the camera right side. Luckily, they had anticipated that someone might want to do something crazy with the 235, and had left some room for the board and extra connector in the 235 design. To control the dual lenses and convergence we used the ARRI Wireless Remote System with custom software. Four ARRI lens motors controlled iris and focus in perfect sync, while a fifth motor controlled convergence. The framing is performed by looking at the video assist images on two 5.8” LCD monitors located on the cameras. This made it possible for Dylan Reade, our operator, to view and operate with the first ever, stereoscopic live action images by simply using crossed-over eye technique, which is sometimes also called "free-viewing". Alternatively, the video assist image can be viewed on video goggles. Since only the video assist of one 235 was physically modified, replacing a camera body in an emergency, as well as using the cameras for other, non-3D purposes, is easily possible.

Our first tests turned out better than expected, especially for the critical close focus shots where the distance between the lenses, still greater than the distance between the human eyes, can play havoc with the 3D effect. This distance is called the inter-axial distance.

Thus encouraged, we went ahead and created an articulating base plate that includes an adjustment for convergence, the angle of the optical axis’ to each other. Having convergence on the fly in a compact 3D rig is a real first. It allowed us to adjust convergence to match the lens’ focal length, helping us to visually push the subject away from more aggressive 3D that is the result of wider inter-axial distance and increased parallax. A long standing Toronto-based film industry machinist, Willy Nikodemus, created the base plate that is at the heart of the ARRI 235 3D rig. His designs were made based on my CAD drawings that were sometimes only minutes old. There was a lot of testing and several attempts to get proper control of the torque required to accurately “toe in” fully-dressed cameras on the fly. At the end, Willy installed a revised control mechanism literally seconds prior to shipping to the first location, the Ghost Ranch in New Mexico, and then straight into the scorching sand of the Gobi Desert in Mongolia.

There we used the rig and all the controls we had built to shoot to its fullest extent. Keeping all the parameters needed for a good 3D shot is tricky; you have to balance convergence, focal length, inter-axial distance, distance to subject, lens distortion, type of set and subject and various other factors. Our advice: “Don’t do this at home”! Aside from our experience, we used 3D ‘apparent distance’ software developed by IMAX to determine the correct convergence settings. I was many times observed hiding under a dark cloth to make these calculations on my Palm Pilot.

The results were astounding. The Ultra Prime lenses recorded beautiful distortion-free images at T2. The complete rig, consisting of two 235 cameras named "Arnold" and "Richter", two Ultra Prime lenses and five CLM-1 lens motors, weighs only 50 lbs (22.7 Kg), that is 175 lbs less (80 Kg) than the IMAX Solido 3D camera! In fact, it is even smaller than most equivalent HD rigs, since high-res storage is built-in. The whole rig operates relatively quietly and we get the benefit of film’s inherent advantages, including 4K resolution, higher contrast range and natural color reproduction.

The 235 3D rig completely changed the way we work on IMAX 3D movies. Suddenly we can do things that every normal feature film crew is used to, but that is impossible with a 225 lbs camera at T4.5. We went hand held, we flew this rig under perfect control on the Panther crane with a 36 foot reach, we placed it on the Sky Jib, flew in a helicopter with the rig on a Nettman Stab-C head, flew in a helicopter of the Central Mongolian Airways, Jeff Mart flew it on his Steadicam, it was mounted on the bumper of a Toyota Land Cruiser and bolted on top of vehicles in the Gobi desert. We were able to run up and down a river bed with a Steadicam on a cart, the same way a Dinosaur would have done. We shot background plates in dark locations with available light while still getting enough depth of field to keep the CG guys happy. Never once did we have a single failure of any kind. The whole thing worked right out of the box. Thank you ARRI

Originally the plan had been to shoot about 10% of Dinosaurs Alive! with the 235 rig, but the rig worked so well and gave us such freedom in terms of weight, lens speed and camera mobility, that we ended up using it for more than half of the film. Months later after the up-res work at Lowry digital in LA, the producer David Clark reported from The Giant Screen Theatre Association Galveston conference that when screening the Dinosaurs Alive! trailer, the difference between the 3D images from the 235 3D rig and the 70 mm IMAX footage was imperceptible. The success of this rig changes some of the conventional rules for large format production. While wide angle vistas are still best recorded on the larger 65 mm negative, we have proven that recent advances in film stock, camera, lens and digital intermediate technology make the use of smaller and lighter 35 mm cameras possible.

Dinosaurs Alive! is scheduled to be released in mid-2007. We will continue to use this rig to shoot other exiting sequences for future IMAX 3D movies, including our next project, a Stephen Low IMAX 3Dâ„¢ film titled Legends of the Sky. We are already planning a new lighter and more compact convergence base plate that allows us to vary the inter-axial distance, that is to move the cameras farther apart from each other for more aggressive Steadicam work. In addition, other opportunities are already presenting themselves. Many of the digital cinema projectors that are being installed all over the world are "3D ready" and there is a new push to digitally convert existing 2D movies to 3D and to shoot new, original 3D material. I believe that this will open up the market and we will see a major increase in the number of 3D movies shot and shown.

Ultimately, I think producers will ad high frame rates to 3D, since the combination of high frame rate 3D image capture with high frame rate 3D projection can create a fully immersive, ultra-realistic environment in any digital cinema. The best way to capture those high frame rate 3D images is film. So our goal is to further develop film based 3D cameras to capture high volumes of information at 48 fps. These cameras will be able to supply gorgeous 3D images for large format 3D projection and for mainstream 3D feature films in the future.

The crew of Dinosaurs Alive! In the Mongolian desert.

Written by William Reeve, CSC, with input from William White, Sebastien Laffoux and Marc Shipman-Mueller.

For inquiries into renting the 235 3D rig, contact the 3D Camera Company at 1 Westside Drive, Unit # 12, Toronto, Ontario, Canada, M9C-1S2, telephone: +1 416-622-9925