Flipped camera compounds rolling shutter?

[David Newman]

There is an excellent reason for flipping that camera for the closer inter-axial. GoPro subjects can get very close to the lens, for that type of 3D image to work the IA needs to be short.

[Chris Hurd]

Originally Posted by Mark Pavy

one camera upside down.

But that is indeed the proper way to do it... to get as small an inter-axial distance as possible.

[Mark Pavy]

Yeah, I know why they did it....not everyone wants to film themselves jumping off a cliff with the cameras pointing at their head. I'd just like them to release the prototype (as well) that had an interocular of 61mm versus 32mm on the one that is released.

[John Reeve]

What you gain in decreased inter-axial you probably lose in shutters rolling in the opposite direction. these are CMOS sensors right?

[Chris Hurd]

Posts above split out from http://www.dvinfo.net/forum/cineform...ght-gopro.html

[John Reeve]

Thanks Chris,

The reason I mentioned this was because I've seen shutters rolling in different directions on mirror rigs a lot. I imagine this situation with the GoPro's would be exactly the same effect unless the new gopros have a global shutter or are CCD?


John

[David Newman]

My understanding is flipped camera is clocked in reverse, so the rolling shutter matches. Cool huh? While I'm not in the Firmware department, bit I've using the results for sometime -- this is not an issue.

[Steve LaPierre]

Originally Posted by Mark Pavy

Yeah, I know why they did it....not everyone wants to film themselves jumping off a cliff with the cameras pointing at their head. I'd just like them to release the prototype (as well) that had an interocular of 61mm versus 32mm on the one that is released.

Can't you spread the cameras apart to the IA you want, just not use their case, or is the cable too short?

I have to say it: your an Aussie, so don't you have to shoot everything upside down anyway! Sorry, just couldn't resist.

[David Newman]

The cable is designed for the short IA.

[Mark Pavy]

@Steve- yes, you're right. I shot a whole lot of ski footage with 2 GoPros with a rig I made myself 8 mths ago. Oh man do I love skiing uphill and catching the lifts downhill- it's all messed up here, with things being upside down!!! lol

[Craig Davidson]

They use a negative going clock pulse on the upside-down camera so it runs backwards ;-)

[Carlo Macchiavello]

Originally Posted by John Reeve

The reason I mentioned this was because I've seen shutters rolling in different directions on mirror rigs a lot. I imagine this situation with the GoPro's would be exactly the same effect unless the new gopros have a global shutter or are CCD?

and this cause a lots of headaches of post department and to all viewer...
usually this is difficult to solve in post, and give you a lot's of strain when you see stereo movie.
It's a bad developing of rig, most of pro beam splitter rig allow you to reverse camera to avoid conflictual rolling shutter.

[Tim Dashwood]

Can anyone confirm that the shutters are actually synchronized? My understanding after NAB was that the sync cable not only synched menu items and start/stop but also the genlock/shutters. However, I just had a conversation with someone who has used them and I was told that there is no actual shutter clock sync between the two cameras. If this is the case it won't work well for 24fps - 30fps shooting. I'm just looking for another confirmation on this before I buy a couple myself.

[David Newman]

The frames are sync'd, and work well for 30p and 25p (no 24p) shooting.

[Tim Dashwood]

Thanks for confirming things work as expected David. We do a lot of fast action stunt work so we need perfect shutter sync. I'm placing an order this week.