Looking Around Corners using Femto-Photography

The MIT Media Lab, that I mentioned previously when they published their experiment consisting in filming the very propagation of light, strikes again by using their device to take pictures of objects hidden from the line of sight.

Update: there is now a TED talk presenting femto photography.

Unintentional film looking shot

Snow suddenly started to fall over Tokyo last night, quickly building a white layer over the never ending city. I was too lazy to grab my gear and all the stuff one needs to get out during a cold night, so I just hoped the snow would still be there on the morning and decided that I would take my camera with me on my way to work.

It was still there (although it had become ice) and it was giving the morning sunlight some exquisite tones. I love the morning light anyway: grazing, harsh, drawing bold shadows on faces and buildings… But the reflections due to the snow really make a difference.

While waiting for the train on the platform, I wanted to take a picture of that girl on the other side, lit by that light. But I didn’t even have time to aim and the train was there already. I took the shot anyway, in the hope I would catch it through the window.

The result is a bit unexpected: the tinted glass and blacklit inside give the picture a film feeling, as if tones were post-processed and black mattes were added.

The filmic train

The filmic train


Visualizing specular component in real life

Graphics programmers are quite used to the idea of specular highlight. It is usually more or less understood, or accepted, to be the reflected part of the incoming light, on top of the one that sort of bounces in every direction and that is referred to as the diffuse part. The specular term happens to have a very physical meaning though (which I won’t elaborate on for this time) and the interesting property of being polarized while the diffuse part is not.

This property is used by photographers, who add polarizing filters to their gear in order to eliminate glares and reflections from their shots when taking photos through glass or water for instance.

John Hable has written a very interesting article showing how to split specular and diffuse in real images. He later wrote another article showing that specular often contributes more than we expect for matte materials. Both help giving an idea of the importance of the specular term as well as getting the eye trained to identify it.