Infrared photography back in the film days was simple. You just picked up a roll of infrared sensitive film and off you went.
On digital cameras, the sensor is actually sensitive to light with wavelengths within the IR-range. Due to this, the manufacturers of the cameras has designed the cameras with an built-in IR cut-off filter. Otherwise our images would be really interesting, but not very photo-realistic.
The filters, how-ever, still lets a tiny-winy amount of IR light in. So what you can do, without disassembling your camera, is to add an IR-filter that cuts away visible light. I bought a cheap one from China just to test what the results would be. The one I used has a cut off well above 940 nm. This means that it takes away most of the visible light. This makes the exposures super long. For the shot below I was using ISO 800 and a 30s exposure. It was early morning light on the island of Klädesholmen.
These settings gives quite grainy images. It’s still a cool look though.
One thing with using an infrared filter is that the cameras metering system gets thrown off. It seems as the Canon EOS 70D underexposes terribly with the filter on. I would expect it to overexpose, thinking it wouldn’t be sensitive to the IR-spectrum. Well, surprise, surprise. Test and shoot had to be my approach.
I did some very basic settings in Lightroom, trying to alleviate some of the graininess and the softness of the image. It’s still a very interesting effect, and I will definitely try this again.