We Want Mirrors

Post date: Feb 27, 2015 7:29:43 PM

(it's a pun on my site name - see Why "a sham"?)

I had a very "woah" moment when I realised this: A photo taken along a reflective surface, gives you a stereo pair of views of whatever is reflected.

This image above is Summer Bear Lake by Joel Higgs.

Here are a bunch of other examples, cross your eyes to see them in 3D. And background and explanation are below.

Explanation

You can take a stereo photo... sort of, with a mirror.When you take a photo next to a mirror, you see some stuff and a mirrored version of the same stuff.

It's complicated, I know. With me so far?

But you're looking at the reflected stuff at a different angle to the real real stuff. If you flip the image the other way (so it's mirrored), it's like a second image of all that stuff from a different angle.

In my diagram, look at the real stuff.

Real you (red) sees it from the left, and mirror-you (blue) sees it from the right. Stereo.

Using a mirror attached to a camera for 3D is not a common or well-known approach, but it's hardly new. A whole system was developed for cameras with matching viewers in the 70s (very clever! Worth a look!), and there was even an iphone version as a kickstarter project.

But,

The mirror doesn't have to be attached to the camera!

However obvious it is once you see it, nobody else that I could find, is using reflections off lakes or buildings to take 3D stereo photos of things. What's more is that you don't even need to cut the image in half (which is tricky to do right, if you think about it).

I showed the folks at the Sydney Stereo Camera Club last meeting, some of whom have been into stereo in a serious way since the 1970s. I was hoping to learn about who else had done something like this. I received a really nice compliment, it was

"w ww... wait. What? What am I looking at? Can you go back to the diagram?".

To a researcher / engineer / scientist, there is no sweeter praise than (interested) surprise.