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Help Exact timing between 3D camera photos

S

SplitVision

Lurker
Hi all!
I wonder if the two 3D cams have their exposure exactly simultaneously, or if there is a time lag between them. And if there is a lag, is it absolutely constant, e.g. the lag is always 5 ms, never 4 ms?

Could someone who owns it please try to take a picture which reveals if the two images are taken simultaneously or not? Like, a picture of a motive which changes very very fast.

I suppose that it is possible to view the two images individually. Is it? If so, do they look like two normal images, or are they somehow scrambled?

The background is that I want to take two images exactly simultaneously or with a known exact time lag. Not in order to produce a 3D image, though, but I want to use a mirror in front of one of the cameras, so that I can capture two different motives. And it is necessary for my "experiment" that I know that images are taken simultaneously or have a constant time lag.

Any answer, speculation, link or idea is welcome! :)
 
LOL, sounds like you got a lot of ideas going on in your head, anyway the 3d picture is taken simultaneously. Also, it is two normal pictures that can be viewed individually.
 
That'd be great news! :)
But are you absolutely sure?

I'm learning java intensely now with the intent to write Android apps. And yes, I do have a lot of crazy ideas! There's no chance to do real time programming in java on Android, I suppose. So I could never measure the exact timing of photos. But if with 3D I can rely on that two images are taken at the same time, then I could have one camera shoot a "clock" consisting of a binary LED counter with millisecond precision. That way I will know the time interval between images, even if the OS starts doing garbage collection or whatever while my code runs.

And I need perfect timing in order to calculate how objects in the (other) photo move and predict exactly where they will be a few seconds into the future. I think there are many applications for that. Well, some anyway...
 
SplitVision said:
Hi all!
I wonder if the two 3D cams have their exposure exactly simultaneously, or if there is a time lag between them. And if there is a lag, is it absolutely constant, e.g. the lag is always 5 ms, never 4 ms?
Click to expand...

There can not be/should not be/must not be a lag. Successful stereo requires that both images be taken simultaneously. Otherwise you have problems. The exposures must be identical, the focal length of the lenses and your focus must be equal.
 
Bob Maxey said:
There can not be/should not be/must not be a lag. Successful stereo requires that both images be taken simultaneously. Otherwise you have problems. The exposures must be identical, the focal length of the lenses and your focus must be equal.
Click to expand...

You would think that the manufacturer would ensure this, but I've proven with several photos that this isn't the case. Even the white balance is independent, which is just silly to me. I've also seen good focus on one side and bad on the other. It's 3D with cell phone cameras. Clearly intended as a toy rather than a serious stereoscopy tool. But that doesn't mean you can't get really good stereo under good lighting conditions. I have some excellent shots as well.
 
Does that include experience with unsynced timing? Image quality is not a concern of mine with respect to this project. Is there any "general wisdom" or such that 3D photo works less well when the motive moves very fast?
 
as far as I can tell, the two sensors captures the images at the same time. Anything moving fast enough to reveal a difference would be so blurred that it wouldn't really reveal anything useful.
 
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