Canon 3D?

[Sareesh Sudhakaran]

Originally Posted by Nick Hiltgen

Sareesh, I think maybe I'm misunderstanding you or you me. While yes long lenses will give you a shallower depth of field, as far as 3d goes it also really does make the charachters seem like they're cardboard cut outs, it appears to be layers of paper instead of an immersive 3d enviornement. Kinda like if you look at something through binoculars.

I think pretty much if you use any lens over let's say a 50mm (in motion picture 35mm terms, divide by 2.5 to get 2/3"-20mm 5.6 or so for 1/3" equivalent 9mm) you'll start to get more binocular vision. To me this isn't really groundbreaking 3d, but then again I'm not really sure what is.

You're right about the cardboard cut out paper effect. It's anything but 3D.

Is it possible to use video lenses (that are on the longer side but still have less DOF) at a distance of 20-30 feet to achieve an 'immersive' 3D effect? If so, it would avoid the use of beam-splitter rigs. I'm just hoping here. Designing a beam-splitter just seems too much of a risk-taking venture and that is before actual shooting.

[Bicky Singh]

any new discoveries about syncing two canon vdslr's together?

The potential of using these camera's for 3D is so huge if only we can overcome this sync problem.

[Nick Hiltgen]

I don't know that DSLR's are really the thing you want to use even if it is possible to genlock the two of them. I think maybe having a camera with something closer to the size of a human iris might make for a really immersive environment, Unfortunately that will probably limit any sort of 2d release. But hey that's really more of an aesthetic thing.

You really don't have to design a beam splitter, there are quite a few DIY guides out there, and if you want a ready made low cost one, then you could check out 3D Film Factory. Creating dynamic entertainment*for a new dimension. I'm not sure of the legitimacy of the company but it's something I'm looking into. At 3500 with offset adapters thats about as cheap as I think you'll find a beam splitter rig.

[Sareesh Sudhakaran]

I agree with you on buying the rig which also comes with the experience those guys have. I wanted to make one cheap to learn the ropes for myself, so to speak.

What cameras in your opinion resemble the human eye, and which can be used for 3D? If DSLRs are out, then I guess so are ARRI lenses. Is that right?

[Adam Stanislav]

Originally Posted by Nick Hiltgen

I think maybe having a camera with something closer to the size of a human iris might make for a really immersive environment

Interesting. That would be the Iconix Studio 2k, I suppose.

[Nick Hiltgen]

Please keep in mind this is strictly untested opinion on my part. I think that 1/3" and 1/4" ccd's or CMOS censors will give a more "you are there" effect as you will have a DOF that is similar to the human eye. Of course, the issue may be that we (as an audience and as filmmakers) have come to expect that Movies are supposed to have a certain depth of field (35mm-motion picture depth).

I think it really depends on the type of filmmaking you're doing to me Immersive usually means boarding on virtual reality as far as camera work goes. If you want just a very deep screen or a large distance between the front of the screen and the back. That would require careful setup of your shots and cameras so as to not get divergence. I think you'll also want to start off with less cuts to let your audience get used to the notion of 3d cutting, but again that's just me. I'm sure there are others out there that can offer other solutions.

[Ben Winter]

To clear the air:

Canon 5Ds and 7Ds can be closely synced but not certifiably gen-locked; this is the method, assuming all camera settings are the same: Press start to begin recording; fire both shutters simultaneously with a dual-wired remote or wireless pocket wizards. The sensors will reset their scan from the top line simultaneously and resume recording video to within a few milliseconds of each other. The sync can be verified by firing a flash at the cameras; the flash should fill only a portion of the frame, but at the same part of the frame on each camera, due to the CMOS shutter roll.

With one camera flipped and the other right-side up, the lenses' centers can be mounted 5" apart at the minimum. Using the 1/30 rule of thumb for 3D shooting (interocular distance is 1/30 of nearest object in the frame), this allows shooting objects as close as 12.5 feet. Any closer requires a split mirror.

Hope this helps.

[David M. Cole]

Originally Posted by Ben Winter

T...Canon 5Ds and 7Ds can be closely synced but not certifiably gen-locked

One method that works well to minimize initial drift is to power the cameras up at exactly the same time using an external power source. This, combined with the ganged hard-wire shutter release to reset the sensor timer is the best approach for sync. My 5D's come up with less than .05ms sync offset, but, unfortunately drift out of sync fairly quickly. The key seems to be to have two cameras that were manufactured at the same time (mine were not).

We have MUCH better luck with Panasonic GH1's and 2's. There is an active group shooting stereo w/ hacked GH1s @ GH1 Stereoscopic Rig Collaboration You can find the design for a simple mechanical sync controller there - as well as sync testing methodology and advice.

[Alister Chapman]

Just consider that if one of the cameras is upside down the any rolling shutter artefacts will go the opposite way on each camera, further complicating alignment.

[Jesse Blanchard]

I have been shooting on a beamsplitter rig with two T2i's. I had a 2.5mm splitter made for me (should get it this week), to split the remote signal to the cameras. I've been told this will give me perfect sync after the photos.

If that doesn't work, I'm going to try powering up both cameras off of the same external battery. They are the same voltage as the larger XHA1 batteries so I think I have a good chance at getting that to work. I'll post my progress once I get there. The t2is do not output HD video via the HDMI port so there are not a good candidate for nano flash recording. Also, the white focus box stays up. You can clear that with Magic Lantern, though.

[David M. Cole]

The T2i's will sync fairly well with a Y-cable on the shutter release - however - the cameras internally poll the shutter release port for the switch closure. This results in some offset, depending on the polling cycle of each camera. Using the external battery to fire-up the cameras will increase your chances of achieving good sync.

Another note on using mechanical switches for powering up the cameras and triggering the shutters... mechanical switches are prone to bounce which could possibly introduce some variance between cameras. Because of this, "purists" use solid-state switches for this purpose. I remain unconvinced that this matters and have achieved perfectly acceptable results with plain old mechanical switches. Your milage may vary.

Finally, most camera manuals warn that you NOT leave the camera power switches in the on position when introducing external power. This is because a surge could fry the camera. I've never had a problem with battery or A/C regulated power sources with Canon or Panasonic cameras, nor have I ever heard of anyone else having a problem. Again, your milage may vary.