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Comment by bprater | Hacker News Reader

While it's accurate that cine cameras use a human focus puller, its an oversight in this cameras engineering not to include a way to drive the len's focus or the aperture. (Blackmagic's early cinema cameras used these 'dumb' mounts, too, but it frustrated users because they couldn't electrically run the len's controls.)

Having an API for the lens and aperture would have opened it up for developers to use these creatively, such as focusing on one point in the frame and then zipping focus to another point using easing functions.

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Blackmagic make video cameras for a specific niche and they're great (I want one myself). But most of their customers buy into the Micro 4/3 mount system. PL mount type cine lenses have never had autofocus and likely never will. The job of the focus puller is not just to keep things in focus but to adjust in harmony with the mood and pace of the scene. There are separate remote lens control systems for when a camera is mounted on a gantry and so on. Framing and focus are treated as distinct jobs on a large set.

Cine lenses don't have camera-operated controls, so it wouldn't work. You could control the aperture of some 'interesting for cinema' lenses (Zeiss Otus for Canon mount, for example) from the camera, but this would require unwarranted amount of reverse engineering.

Active lens mounts are on the road-map: https://www.apertus.org/axiom-beta-status but it will indeed require a serious amount of reverse engineering for each different lens system: https://wiki.apertus.org/index.php/Lens_mounts

Agreed on all points. Due to the modular design, and I'm assuming here, it seems wireless (and on camera) focus pulling could be added onto the cam.

Something like http://www.rtmotion.com/lens-control-system or https://cinegears.com/product/cinegears-single-axis-wireless...

Not sure about aperture adjustment from the cam body itself; usually, not always though, cine lenses are constant aperture primes or zooms.

Cine lenses almost universally have variable aperture. When a zoom is "constant aperture" what is means is that the maximum aperture is the same across the entire focal range, not that you cannot close it down when needed.

Thanks for the correction. That aspect slipped my mind.

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