Canon Pro 90 IS, tripod 9.06mm focal length ISO 50 1 second at f2.8 Lee 87C infrared filter Contrast increased in post-processing

Scenery on alien planets

Nope, not fancy Photoshop tricks, but simply another example of infrared photography like the one found here. At Jones Lake State Park near Elizabethtown, North Carolina, an oddly-shaped tree adds to the otherworldly effect of seeing at infrared wavelengths.

This can be done with film, too, with some adjustments. Lenses work by bending light, and they bend different wavelengths (what we normally consider "different colors") by varying amounts. They're optimized and coated to work best in visible wavelengths, and infrared falls outside of this goal – as a result, limiting the light to only infrared means that you actually end up changing the focus. But since we can't see in infrared, it becomes necessary to have special marks on your lens so you know how to adjust the focus once you add the IR filter.

The digital sensor, however, sees it just fine, and thus digital cameras can still autofocus in IR (provided, of course, that there is no internal IR filter messing with this process). So it becomes much easier to shoot IR with digital.

* A small side note. I don't mean to confuse things by being too vague with my terminology. Infrared filters for cameras and lenses, such as the Lee 87C mentioned in the specs above, are infrared pass filters, which block varying degrees of visible (to us) light. The internal IR filters in many digital cameras, however, are intended for the opposite affect, and thus are infrared blocking filters, letting visible light through. Most times these filters only look like clear glass with a faintly magenta reflective coating, but they're very effective for infrared wavelengths.

Now, an addition as I update this page. If you have Google Earth installed on your computer, definitely click on the placemark at upper left; alternately, you can enter "34 41.023N 78 35.814W" in Bing, Google Maps, Mapquest, et cetera. Now, zoom out a bit until you can see the general layout of the landscape for a few miles.

Do you see the nice collection of ovals? Does that seem odd? It should. They're called "Carolina Bays" and they stretch across many portions of the east coast of the US, with a strange uniformity in orientation. But nobody really knows what caused them – meteorites have been largely ruled out since expected artifacts are not in evidence. When I first heard about them, I started skimming Google Earth trying to find them (the satellite image at that link wasn't a whole lot of help, imagine that,) without realizing that I'd already been right on the edge of one, taking pics. Too cool.