Sync when shooting 3D....how close?

[Philip Powell]

OK. I have fairly good knowledge of stereo shooting in general, and have done a fair amount work creating stereo CGI, but I've never shot any "live" 3D myself.

I realize that perfect sync between two camera, is always what you want. (as has been the topic of a few threads here)

But I've seen some folks shooting "poor mans" stereo with camera's that I know were not in sync, or even capable of it. I even saw a few running around NAB.


So my question is, can "close" yield results that don't suck?? Or is that an absurd proposition? Thanks.

[David Wilson]

Phillp,

To work well under all conditions the cameras truly need to have the shutters in sync but, that said, we've shot with non-synced camera many times in the past that produced seemingly perfect results. Luck can play a part but, clearly, more that luck is the nature of the material being shot. Stands to reason, fast moving subjects require perfect sync as do fast camera motions.

"Close" works fine under many circumstances.

[Leonard Coster]

Hi Philip,

I'd have to say sync is really really important.
When you look at the real world your eyes tend to see things at the same time, unless you keep one closed or something !
If you shoot out of sync you will produce major stereo errors.

If there is no movement in the frame then all is well, but this is motion picture photography after all....

Horizontal displacement will produce parallax depth errors.
Vertical displacement will drag your eyes up/down relative to each other which is:
a) very uncomfortable - producing brain/eye strain fast.
b) impossible to accommodate to any great extent with or without eye strain so your stereo illusion will break.

Basically I'm saying that if anything is moving within the shot then please please lock your cameras up!

Cheers,

Leonard.

[Stuart English]

If there is no movement in the frame then all is well, but this is motion picture photography after all....

That is the crux of the issue, you can create a demo where it's not apparent that there is an issue, but it will bite you soon enough.

[Kirk Melby]

We have shot 60P content with non-genlocked camera's. With a 1/120 sec shutter, +/- 0.5 milliseconds seems to work fine for most normal motion, (not sports, etc.)

[Paul Leeming]

That is the crux of the issue, you can create a demo where it's not apparent that there is an issue, but it will bite you soon enough.
I hope and trust that the Red brains (people, not camera modules!) are already well on top of this.... :wink:

I'm really hoping to see a full raft of stereoscopic accessories announced from Red that fit the Red price model before Epic hits the wild in any significant numbers. Fingers crossed....

Cheers,

Paul