Thursday, September 3, 2009

Perspective Illusion

Silver Fox just posted some photos from a trip to Caliente Nevada. One of the shots prompted me to try creating an illusion I recently saw for the first time:Those two pictures are exactly the same. To me though, the rails in the right picture look more horizontal than the rails in the left photo. I have no idea how this works, but I do find it interesting.


Silver Fox said...

That is kind of weird looking. I think I already rotated the picture some - it's hard to get buildings to look right, they really lean this way and that in our own perspective, which the camera captures differently depending on the lens used.

I think the illusion is created because the picture on the left makes it seem as though there is more space to the right of the left train depot than there really is, so the railroad tracks on the right look closer to us, as though the foreground on the right is closer than it really is. It also looks to me like the real tracks are the part between the two sets of rails.

Nicholas K. said...

This is really cool.

I did notice that the train tracks are much more askew when you focus on both of the pictures at the same time.

When you focus on one picture only and glance at the other picture out of focus the tracks do seem more parallel.

Great post!!!

Silver Fox said...

Have you tried treating the photos as stereo pairs? Merging them with your eyes possibly adds the vaguest amount of depth.

Lockwood said...

SF- yes, I have, and I noticed the same thing. However, I did this by doubling the width of the canvas, copying the image and pasting it back to the new space. The two pics should be digitally identical.

BTW, the trick I noticed with the original (which I wish I had saved in some way) is to find a picture with strong convergence to a vanishing point. Crop at the vanishing point and double the picture. I'd be curious to see if this works all the time.