Definition June 2021 - Web

AER I AL ARRAYS | GEAR

“ANY WIDER THAN 24mm, YOU START TO GET ISSUES WITH DISTORTION”

driven by the need to give VFX the cleanest possible data. “There’s an overlap between images,” Braben points out. “It can be tweaked, but it’s generally a 10% overlap. It changes between sensor sizes, but we usually use the Zeiss CP.3 21mm extended data lens. We can use 24mm, but you don’t want to go any wider than that, because you start to get issues with distortion.” Actually attaching cameras to helicopters is a process complicated by both engineering and

the sort of territory a helicopter shot encompasses. As such, choosing a time, a place and a frame becomes all-important. “Generally, VFX prefers to shoot in flatter light and that’s generally what we do,” Marzano explains. “Occasionally, we’ll shoot in hard light, mostly for a specific effect – particularly in back projection, where they’re using the images to put on an LED screen for actors to play in front of.” With camera and mount in hand, the choice of lenses is often

ABOVE The more cameras attached to an array, the more difficult it is to stabilise them

SINGLE-CAMERA SOLUTION IN FLIGHT When filming fixed-wing aircraft in flight, helicopters can struggle to keep up, making a fixed-wing camera platform necessary. However, the increased speed makes bulky arrays impractical, and XM2 Pursuit is currently testing a single camera called the ‘Nine by Seven’. Stephen Oh says: “It’s 9.3K by 7K, and we can put signature primes on there. Up until now, you couldn’t put an array on a jet, but we believe it will beat a six-camera array on a helicopter.” A single-camera solution also makes life easier for the VFX people: “With an array, you’ve got to stitch – and a stitch point is a potential point of failure. With the Nine by Seven, the file size is huge, but you don’t have to stitch.”

JUNE 202 1 | DEF I N I T ION 29

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