Technical question about 3D movies

No such thing as a stupid question ! Only stupid answers !

Gosh, it is an interesting question. I would hope that the answer is that young Mr Scott will be making a separate 2D edit, selecting the from the best shots available from the cameras...in much the same way that for a regular, good old-fashioned film (i.e. one that was naturally, inevitably 2D), there were often scenes edited together from a multiple takes. In the same way, it seems entirely feasible that the two cameras that were presumably used for filming 'Prometheus' should provide ample material to edit together a really good 2D version without necessarily going for a simple prioritising of one camera angle over the other. But hey, what the hell do I know. Over to you, Ridley.

They shot Prometheus with the new Red Camera, which is also being used on the Hobbit...has double lenses to create the 3D effect and 2D Effect, the camera is great to use.

Interesting detail. Have you used one?

I admit to having no special knowledge on the technical aspect but that is a fascinating inquiry. Would we have two unique 2d versions of Prometheus filmed from different angles or rise... great question NoxWord. Take care everyone.

Sorry, Cain 1977 answered the question .

Cain's post gives some interesting insight and specifies that there is one camera being used, rather than two, but doesn't answer the question, you don't need to apologise, Sundar.

I read RS used four 3d cameras. Three stationary cameras and one steady cam.

I can't say exactly how it works but from a 3D artist's point of view it doesn't matter which footage from either the left or the right dual-cam lens is being used for the 2D cut. The distance is only about 7 cm and it wouldn't make a significant or noticable difference, unless you'd have an extreme close-up. Even if they switch using the left or right one between shots, it would be for the entire length of the shot, therefore you won't see any jumps in perspective. So I guess it's a pretty straight forward process. I used to work with virtual 3D cameras in Maya for rendering 3D footage and could still use the output from one to keep it 2D, so I assume it's very similar to real world 3D camera systems.

Thanks HAL, that's what I was wondering. Except for close ups there is not much difference. Except maybe for long shots where a pebble in the background might be covered by someone's elbow in one shot, while it is visible in the other one. That would be a huge disappointment for that pebble, who might expect to appear on the big screen. It's fascinating that, although very very similar, there are two different versions of the same movie because of parallax.

LOL! That poor little pebble would still appear in the cast and crew listings, unless it was involved on set less than two days or so. But yeah, it could have been his big chance, the turning point in a long career, before turning into sand...

ha! very good question here, that's something I'm also a bit obsessed with... guess I'm leaning a bit too far in the obsessive-compulsive side to really feel comfortable with the idea a movie has 2 versions, and the one I'll never see could hold all the answers (though, really, not...) Guess I'll see Prometheus in 3D, each of my eyes will see a different movie and they'll share the goods... For the record, the 7cm stuff comes from the fact it's roughly the average interpupillary distance in humans ('between your eyes'). It achieves the best 3d stereoscopic effect for depth perception in the nearest ~1.5m, then to a lesser extent up to ~3m before it progressively fades (hence the different consequences for close-ups/distant stuff). Those 7cm are mostly used because they recreate the perception we do have in any environment, so in movies, that's an 'all around good'. However, a different gap can be used between real/software cameras, if you want to give a similarly strong perception of depth looking at something for which it should not be so strong. For example, if you want a strong depth perception on a distant scenery/monument... considering our 7cm gap give its maximum effect ~1m, you can recreate a similarly perceived depth by just reporting this rule of 'gap is 7% of the distance to the object'. Hence, if your monument is 1kilometer away, just leave a 70m distance between your cameras, and audience will perceive depth on this massive structure just like it's at an arm's reach. It also shows how what they call '3D' is really only just 'depth' and 2*2D, and why people don't really buy into their nonsense unless it's a real plus... but well, I'm digressing, and I should be working on that translation! -T.