Digital photography: some things just aren’t possible

Despite the advances in digital photography, we are yet to see a camera which views a scene the same way that our eyes do. True, we aren’t able to capture and store scenes with our eyes, but they do have inherently advanced ability to optically analyze our surroundings, thanks in part to millions of years of coevolution with our brains.

There are some things that just aren’t possible in post-processing digital images. One is removing glare, and reflections from glass. Consider the image below, which was taken directly in front of a shop window. The photograph basically reflects the image from the opposite side of the street. Now getting rid of this is challenging. One idea might be to use a polarizing filter, but that won’t work directly in front of a window (a polarising filter removes light beams with a specific angle. As the sensor doesn’t record the angle of the light beams, it can’t be recreated in post-processing.). Another option is to actually take the shot at a different part of the day, or the night. There is no fancy image processing algorithm that will remove the reflection, although someone has undoubtedly tried. This is a case where the photographic acquisition process is all.

windowReflection

Glass reflection in a shop window.

Any filter that changes properties of the light that isn’t captured by the digital sensor (or film), is impossible to reproduce in post-processing. Sometimes the easiest approach to taking a photograph of something in a window is to wait for an overcast day, or even photograph the scene at night. Here is a similar image taken of a butcher shop in Montreal.

nightviewGlass

Nighttime image, no reflection, and backlit.

This image works well, because the contents of the image are back-lit from within the building. If we aren’t that concerned about the lighting on the building itself, this works nicely – just changes the aesthetics of the image to concentrate more on the meat in the window.