Convergence and Stereo window

I am still undecided about getting a rig (using a W3 at the moment).

One problem that can arise with a rig, I imagine, is convergence
misalignment (no common display is used). I guess that the
convergence should be exactly parallel unless when using hypo
stereo.

My question: Can convergence misalignment be corrected, at least
to a certain degree, in post processing by shifting the two images
within the stereo window?

The reason I got that idea is that the Fuji W3 has something called
'Parallax control' I guess they mean convergence control, but
it is my understanding that a shift in the stereo window is performed.

So, are these two methods equivalent?

Thanks!

Yes, you are correct. Convergence misalignment can be corrected by shifting the two images in post processing, which has the effect of moving the stereo window. And yes, the "Parallax Control" function on the Fuji W3 is actually "Convergence" adjustment.

Convergence it an angle. In the case of a stereo cam, it it the angle between the optical axes of the two lenses and sensors. The Fuji has a FIXED convergence of ZERO degrees (+ - some manufacturing tolerance). CONVERGENCE cannot be changed on the Fuji.

Stereo Window is a CROPPING function of the left/right sides of the image pairs to set set the image frame at a relative position to the contained scene.

The "Parallax" control on the Fuji is a cropping function ONLY, and sets the Stereo Window on the lenticular/barrier display.

Using convergence angles (with fixed sensors and lenses) at values OTHER than zero WILL cause keystone distortion, which can become disturbing at large convergence angles. This distortion can be corrected to a large degree in post-processing.

It would be possible to design 3D cameras with a practical convergence control and NO keystone distortion, if the sensors could be shifted left-to-right with respect to the lenses (thereby changing the angle of the optical axes). The manufacturing costs would increase, as would the lenses manufacturing cost, as they would require a larger image circle.

Wayne

Wonder if olympus ever would allow this with their sensor shift stabalization... would be possible at no big cost! ... how far that sensor can move is another issue- maybe only 1-2mm? maybe thats all you would need?

Use (free) StereoPhotoMaker and all your problems are gone ...

I agree, using StereoPhotoMaker freeware will solve almost all convergence and window issues...CERTAINLY, do not, Do Not, DO NOT USE THE FUJI SOFTWARE THAT COMES WITH THE W3 !

Wayne

Regarding parallax, alignment and convergence, and other technical issues there is some enlightening reading to be found here.................

http://www.dashwood3d.com/blog/beginners-guide-to-shooting-stereoscopic-3d/

Post recording, alignment for stills can be carried out in stereophoto maker, and alignment is easily adjusted for videos, in Magix 17 Pro plus HD or Magix 18MX video editor programmes, and maybe stereomovie maker as well, although I can't say for sure as I haven't used that programme.

Thomas