With many clients navigating through the minefield of shooting 3D through variable-magnification optics, Polecam demonstrates the advantages of deploying prime lenses and moving the cameras towards the subject rather than zooming into close-up.
Polecam founder and Managing Director Steffan Hewitt said, "Our approach to 3D, developed over several years and already used on-air, follows the KISS principle: Keep it Simple." The Polecam live 3D technique consists of two Toshiba IK-HD1 ultra-compact HD cameras mounted side by side on a 3D Head feeding two camera control units mounted at the base of the rig. Each CCU sends HD-SDI to an Inition StereoBrain creating an integrated 3D signal which is then fed to a stereoscopic display. The monitor employed at NAB was a 46 inch JVC GD-463D10 LCD screen using Xpol circular polarization for natural 3D reproduction."
Simple, yet effective
Both cameras are locked down and use roll and tilt at the front to achieve the required pixel-to-pixel alignment. When shooting content to recorders, it tends to capture images with the cameras in parallel and adjust in post. For live shooting, the Polecam 3D rig allows adjustable convergence control between takes by the operator. The standard lens aperture range is f2.2 to f16 and a single motor drives the iris on both lenses and the two cameras are genlocked to each other.
"Using prime lenses gives us massive depth of field," adds Greg Salman of Polecam USA. "If 3D producers choose to deploy zoom lenses, these need tracking and racking which in turn requires a much bigger, more complicated and more expensive rig. Using the Polecam system, the boom is the zoom. Our side-by-side system is compact and lightweight, giving great creative freedom. With the cameras spaced at about 40 mm interocular distance, we delivered solid 3D from foreground content right through to the far depths of the Central Hall with no need for intermediate adjustments. We achieved such high realism that you could easily imagine you were looking in a mirror. And the costs we are talking about are way below the competition."
Polecam's 3D-Narrow head attaches directly to all standard Polecam rigs. It is designed for normal studio shooting and close-ups where cameramen need to match normal human eye spacing. Setup is quick and easy, conforming to Polecam's strategy of ensuring high mobility and operational efficiency. An optional variant, the 3D-Wide head allows the distance between cameras to be extended to 'hyperstereo' which increases the 3D effect for more distant subjects. Polecam's 3D-Narrow and 3D-Wide heads both retain the freedom to achieve sweeping 3D HD sequences that, for the viewer, almost amount to flying.
