Recently I’ve made some good use of old security/CCTV cams that I’ve found lying around in repurpose shops and despite me not being much of a camera guy, I’ve gotten curious experimenting with any piece of camera gear and appropriately fitting lenses that I can get my hands on for the pursuit of VJ science. Just a few moments ago, I got to thinking about the possibility of incorporating an infrared camera and its potential uses as a video source in the glitch chain.
Unfortunately, I don’t know much about the properties of light in general, let alone infrared videography, beyond the basic idea that IR cameras can make the temperature of objects visible to human eyes, where hotter things appear vibrant and cooler things appear muted. So this makes its usage popular for picking up activity in a space that would otherwise be too dark for a normal camera. Nightvision!
My primary question about infrared as it relates to video art is:
How does an infrared camera perceive the light frequencies emitted from a display? OK, maybe not a CRT or LCD monitor, which I assume would just appear as a bright brick of heat, but what about rescanning a projector screen? Would the camera still be able to render lines and shapes of the displayed image in a usable way according to shades of color? Or would it just appear to the camera as a big solid heat sheet? I reckon the distance of the projector’s throw and sensitivity of the camera sensor are significant factors here that could make a difference, hmmmm. Maybe there exists some type of material that could be used as a filter between a projector and screen that might make it look more interesting thru infrared eyes?
Apologies if I’m missing some elementary (middle? high school? I am a product of the American public education system FML) concepts with this train of thought, my posting here is mostly just me trying to entertain my broad curiosity of this idea being creatively viable in any way.
Have you ever thought about using IR or other experiments with unconventional light frequencies in your art? General suggestions for types of cameras/lenses that may yield interesting results? Should I go back and watch some Bill Nye videos to catch me up on basic properties of our (meta)physical plane? Lemme know! Cheers.
I think that there are two types of cameras that use infrared light. The ones that would be part of a CCTV/security setup usually have a ring of little IR LEDs around the lens. You also see these on cameras for baby monitor setups. These are using IR rays as a way to “light” up the subject with invisible rays. They then take the reflected IR and render it as a greyscale image.
Then there are the “Predator vision” thermal cameras. These don’t send out their own IR rays, but rather capture the ones emitted from objects based on temperature. The images from these are usually false colored in the way you picture if you think of a thermal image (blue=cold yellow=hot).
I don’t know about how a television looks through either, but I would imagine you’re right that they wouldn’t look terribly interesting. However, given the definition that you get from the former type of camera, it’s possible they could look interesting, but they may also just get blown out by the light emitted from the screen.
As for filters, I know that the Raspberry Pi NoIR camera (which does not have an infrared filter) comes with a little blue plastic filter (or gel) that can be used to gauge plant health. So various colored gels may give you neat effects.
Sorry to not have the exact answer, but hopefully some of this is useful.
I have one of the old, 90s Nikon digital cameras that doesn’t have an IR filter and works for IR photography, but it needs a LONG exposure and I could never find an IR light source bright enough to get usable video out of it that wasn’t prohibitively expensive. AFAIK CCD cameras are a lot more sensitive, but you need one that doesn’t have a built in IR filter (or you need to be comfortable opening it up and taking the filter out; I’m pretty comfortable modfying stuff but I looked in to doing that to a different camera a couple years ago and it was way to fussy for me to bother). So purpose built cameras are probably the way to go.
I guess in a live show setting, you could use an IR source to lighten the subject or the environment in a way that would only be visible in the IR camera, not to the audience naked eyes