Plants and infrared light

If you have ever seen plants photographed using infrared film, you will know that they have a weird glowing quality when viewed at those wavelengths.

Apparently, the reason behind this has to do with quantum mechanics and photosynthesis. Photons with shorter wavelengths (violet and beyond) have higher energy than those with longer wavelengths (red and beyond, in the other direction). Since only photons with a certain level of energy can be used by photosystems I and II in chloroplasts, plants reflect insufficiently energetic photons, rather than absorbing them. This keeps them from taking in uselessly low energy photons which would simply turn into heat, rather than powering their photosynthetic machinery.

Author: Milan

In the spring of 2005, I graduated from the University of British Columbia with a degree in International Relations and a general focus in the area of environmental politics. In the fall of 2005, I began reading for an M.Phil in IR at Wadham College, Oxford. Outside school, I am very interested in photography, writing, and the outdoors. I am writing this blog to keep in touch with friends and family around the world, provide a more personal view of graduate student life in Oxford, and pass on some lessons I've learned here.

2 thoughts on “Plants and infrared light”

  1. I used to use IF B&W semiregularly. Loved the pale leaves… and the daylight skies that gradated kind of eerily from pale gray at the horizon to intensely black overhead… the results were worth the headache of composing through a dark red filter.

  2. I only tried IR film once – shooting night scenes with a photographer from Victoria. Unfortunately, something went wrong with the roll I used and it was completely fogged.

    It would probably be worth trying again, when I am in the mood to shoot film.

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