The Upload section of Make is dedicated to “digital arts and crafts.” This can include any process, device, or software that you can tweak or hack to create digital, “uploadable” output. As the editor of this section I’ve pursued topics including how to make a chroma-keyed, “green-screen” video, how to use software that facilitates music synthesis on a desktop computer, and how to write a BASIC program to generate plaintext proverbs as a simple form of AI.
Some time ago we published a piece by Richard Kadrey on infra-red photography, describing how to adapt a digital camera so that it will photograph wavelengths just below the visible spectrum. Shortly after that I bought a Fuji IS-1, which is specifically designed to photograph infra-red, since it omits the blocking filter that protects the sensors on most cameras. The picture above, of a sandy wash in the desert, was taken with an IS-1. Of course you still need a filter to block visible light, but these are readily available from photo supply sources online.
Recently on www.boingboing.net a couple of readers suggested infra-red flash photography, which would be done by putting a visible-light blocking filter over the flash source. This would enable you to take pictures surreptitiously in darkness or near-darkness. I’m wondering if anyone here has had personal experience with this. Does the pop-up flash on a typical camera emit enough infra-red to make it workable? How about using a battery-powered camcorder floodlight, repackaged in a light-tight box with a filter on the front? That could cause overheating problems, but if all you want is to take still photographs, you could switch on the light for just a few seconds.
I’m interested in exploring the infra-red topic further in the Upload section of future issues of Make.
4 thoughts on “Viewing Infra-Red”
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I’ve shot a bit with Kodak HIE (before it disappeared) and an IR flash, and recently started using an IR-converted D100 for the same. Filtered flashes seem to rate about one stop lower in IR than they do in visible light, which is no problem at all in most situations. In other words, the filtered on-camera flash will work in any situation where the unfiltered on-camera flash would work.
The big catch is that to minimise the focusing adjustment, you prefer to use f/8 or higher, which minimises the effective distance of most on-camera flashes. You get a lot more flexibility from even a small hotshoe flash – I like the Contax TLA200, which has a lot of power for its size, though I’ve used big Canon and Vivitar flashses as well.
Examples: http://www.flickr.com/photos/matt/sets/72157611983939693/
I used this: http://amasci.com/amateur/irgoggl.html
and bought the recommended gels to filter the Xenon flash. Got plenty of detectable IR output, but my app wasn’t photography, so no details on exposure relative to visual images.