Lately I've been getting back into photography. One avenue I've been exploring is emulating the look of the now defunct Kodak Aerochrome film. It was a film used in surveillance, especially looking at foliage from high altitude spy planes. It renders NIR light as bright red. Following some instructionals from Christoph over at hiddenrealms.ch, I picked up a triple bandpass filte which lets in red, green and NIR light only. (TODO: add measured image graph of the spectrum). In a full-spectrum modified camera, the blue section of the Bayer fiter gets in the NIR light, and nothing else. This means you have an image with red, green and NIR light. By swapping channels (And doing a white balance), output red gets blue, output green gets red, and output blue gets green (A barrel swap), you get images like the below.
Christoph does a /much/ better job explaining it, but I think my results look pretty good.
My next steps are to to make a script to perform the white balance and channel swap in one step, right now, there's a lot of manual steps in Photoshop, which limits my throughput.
I find the last image particularly interesting, as it shows some scientific application for this process (Not that looking cool isn't worthy on its own!) The hat and the ring on the lens are black in human-visible light. However they reflect massively in NIR. Note that NIR is different than thermal IR, it is closer to red light than what a thermal camera can see.