PRODUCTION. METADATA
“If there’s a snag, it’s that this technology is part of an interdependent network. The lens is only the start”
as part of the metadata. Beyond that, the recent /i3 edition of Cooke’s protocol makes provision for accelerometer and inclinometer data to be stored, tracking both the angle of the lens with respect to gravity and its position in space. While that sort of inertial navigation won’t provide enough precision to track a VFX shot on its own, it helps a lot in edge cases, such as fast camera movement or tracking markers being lost behind foreground objects. MAKING CONTACT If there’s a snag, it’s that this technology is part of an interdependent network. The lens is only the start – the camera must implement the right contacts in the lens mount and record data in its files, or pass the data to an external recorder. Some lenses, particularly from Zeiss and Fujifilm, have a connector from which the data can be retrieved in circumstances where the camera doesn’t implement metadata. Although, that’s something else an off-board recorder needs to support. Then, the data must make it through the transcoding process and be supported by the post-production software. This presents a daunting array of potential failure points, but with some
designs use absolute (rather than relative) encoders. They can handle a larger bulk of data crossing between lens and camera. Similarly, Cooke’s /i has moved through /i2 (i squared) to /i3 (i cubed). More recent incarnations added things like distortion and shading maps, where the barrel distortion of a particular lens and its vignetting are described in data held on the lens and sent to the camera
Keeping it in the picture
continues. “You’ll often find certain tools will strip this stuff, so it’s important to pay attention. At the point you’re doing dailies, you don’t necessarily know how or why this metadata may be useful later in the process. It’s a mistake to assume that, just because you don’t yet know what something is for, it may not be useful to someone else eventually.”
different recording device, you have to make sure you’re going to preserve that data.” Ensuring the data makes it off the lens and onto the original camera file is one thing; keeping it accessible is another. “If the DIT does any sort of processing at all, you have to be extremely careful not to strip lots of this information,” Woolfson
Molinare offers digital lab services that typify much of a modern DIT’s work. Darren Woolfson, the company’s director of technology and visual services, is enthusiastic about lens metadata, but strikes a note of caution. “If you’re shooting on an Alexa and recording to a Codex recorder, the metadata will be preserved. If you use a
58. DEFINITIONMAGAZINE.COM
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