Infrared photography can give some very pretty results. It’s also a lot of fun for the technically inclined because there are so many opportunities to mess with hardware and software.
A little background
Camera sensors are sensitive to anything from UV up to low infrared – not high enough to be very useful for infrared heat sensing, but comfortably out of the human visual spectrum. Unfortunately, the result is that camera sensors produce some pretty nasty images when faced with infrared sources such as the sun. Sensibly, therefore, camera manufacturers filter out the vast majority of infrared on the way to the sensor, resulting in good-quality images.
This means that if you as a photographer have decided that you like infrared and want to make use of it, you are required to aggressively filter out everything but infrared so that only the infrared image is stored by the sensor. For that, you use an infrared transmitting filter, which blocks visible light but not infrared, like the Hoya R72, RM90, Tiffen opaque #87, B&W 093 or their many inexpensive cousins (personally I find Neewer filters cheap and fun to play with). But because the infrared blocking filter on the sensor inside your camera is already filtering out most of the light, the result is as though you are taking a photograph in a very dark environment. Exposure times become very long, so long that you must use a tripod and, by preference, a static subject.
The logical thing to do, if you’re going to do a lot of infrared work, is to remove the internal infrared blocking filter. One downside is that it renders your camera useless for visible-light work, unless you retrofit an external infrared blocking filter, such as the Hoya UV IR Cut filter and its cutprice eBay cousins. The second downside is that infrared blocking filters, being lumps of glass inside a camera, are part of your camera’s focus path. Removing them without replacement generally alters your camera’s ability to focus, so people will often replace them either with plain glass cut to the appropriate dimensions (these guys recommend Schott WG280) or with an internal infrared transmitting filter, which allows only infrared light through to the sensor. This second option means that you cannot use your camera for visible-light work, of course. Additionally, on specific cameras, the removal of infrared blocking filters will require the removal of anti-dust filters, some of which filter infrared light too. Like most invasive operations this is also generally a warranty-voiding and hazardous activity, so people tend to convert older cameras.
Online information about digital infrared conversions
This post exists solely because I have too many open links on my browser right now, all pointing to useful resources about converting different cameras. I’m currently trying to choose another camera to convert. If I find other useful pages, I’ll add links to them.
Fujifilm IS-1, IS-PRO and S3 Pro UVIR
Born infrared, these cameras, intended mostly for specialist and law-enforcement work. It is possible to buy a UVIR blocking filter to put on top of the sensor.
It turns out that Sigma’s DSLRs are uniquely simple to use for digital infrared photography. Simply remove the lens and you’ll find the infrared-blocking filter sitting on top of the reflex mirror. It is easily removed, designed this way in order to facilitate cleaning the sensor. Apparently the same is true of the SD10, SD11 and SD14, so presumably the whole range is built this way.
Lifepixel tutorials for infrared conversion
Lifepixel, who offer an infrared conversion service, publish tutorials for some cameras.
Video tutorial on YouTube for the DSC-H9
Sony NEX series
Disassembling the NEX-3
Flickr overview of NEX disassembly
Disassembly gallery for the NEX-5 (Pete Ganzel)
NEX-5 teardown and IR conversion
Disassembly gallery for the NEX-5N (O. Holovachov)
Disassembling the NEX-3 (O. Holovachov)
Discussion and advice thread on Dyxum forum
At least it doesn’t require soldering: the Lifepixel tutorial for the Panasonic GF1.
Panasonic Lumix DMC-G1 tutorial video on YouTube
Observations on the conversion of a Panasonic G3 from Enrico Savazzi
Nikon V1 tutorial thread