Parallax Distortion

3 posts / 0 new
Last post
Robert Fehnel
Robert Fehnel's picture
Parallax Distortion

Earlier this year Gerry gave a great presentation about panoramas. I am left with a question though.

Let me give a scenario. Let's say that i have a tripod with a pan/tilt head (instead of ball head) to which i have attached a rail system, and then my camera. I have adjusted the tripod and camera such that the camera is level and if i were to move the head to take a panorama it would remain level. Also lets assume i have moved the rails in such a way that the parallax distortion is removed when panning the camera left to right as you would for a horizontal panorama.

So far this makes sense to me.

But now lets say that i want to tilt my camera. This would let me take more images so that perhaps i create a grid of images that overlap perhaps 3 high by 4 wide. Although moving left to right there was no distortion, does this hold true for other motions?

I hope this question makes sense.

Anton Largiader
Anton Largiader's picture

Sounds like you are asking about the Brenizer method, which isn't really a panorama in the same sense, so it doesn't necessarily share the concerns that Gerry addressed.

Holding the camera level (horizontally) eliminates the vertical convergence because vertical objects tend to be exactly vertical and your camera sensor is exactly vertical. Applying that thinking horizontally is difficult because horizontal object faces can be facing any direction, and obviously you are changing the angle of the sensor to those objects as you pan. There IS distortion as you pan, but software deals with it and what's left probably isn't objectionable because our brains expect it to be there.

If you layer a couple of panorama rows, you're going to be doing it by tilting the camera so you will get vertical convergence in every row where the sensor is tilted. You need to buy a shift lens. :)

Robert Fehnel
Robert Fehnel's picture

Ok makes sense. And yes i have been looking at brenizer method photos. I definitely find them very interesting. We did have a judge a while back who also created these large panoramas by stitching together a grid of photos. It would seem that if i remove the horizontal panning distortions that leaves only vertical which the software may remove.

Speaking of which i have heard that Microsoft ICE has done a real nice job of stitching as well.