LifePixel-Modified Canon 20D Infrared Camera

A winery in Napa in near-infrared, taken with a LifePixel-modified Canon 20D

I've been shooting near-infrared images using digital cameras since 1998. Pretty much ever digital camera model since the beginning of digital cameras has been sensitive to infrared light (in varying degrees), but it's safe to say that none of them (except for the Canon 20Da) have been suitable for serious infrared shooting out-of-the-box. The reason is that all digital cameras are sold with infrared-blocking ("hot-mirror") filters is that consumer cameras are designed only to record visible light, which is the spectrum of light that most people care about. Still, by placing a visible light filter over the front of a standard digital camera's lens, you may be able to capture infrared images. The problem is that too little infrared light makes it to your camera's sensor, and you will inevitably be forced to shoot with high ISOs and long shutter speeds (in the seconds).

Luckily, the sensors in digital cameras are actually about as sensitive to near-infrared light as they are to visible light, and with careful modification, can be converted to being very effective infrared cameras. With a modified camera, one can shoot infrared images with similar exposure times to standard, visible-light photography. Hand-held infrared photography suddenly becomes a possibility.

To date, I've owned three modified digital cameras for infared use.

The first was a Nikon Coolpix 990 modified by Gary Traveis. Back then, all modifications were done by serious hobbyists. Gary had to get someone to machine an optical element to replace the removed hot-mirror filter. Using a compact camera for infrared was fantastic because the live-preview LCD on the camera actually showed the picture in infrared. It was like having an infrared video camera! But as we all know, images from digital SLRs are much better than images shot from compact cameras, so I had to move on.

The second camera was a modified Canon D60 digital SLR, also modified by Gary. To get this camera modified, I had to source an optical element to replace the removed hot-mirror filter. Unfortunately, I had to buy 10 of them, and I only used 1 -- not so cost effective. In order to be more flexible with my approach to infrared photography, I elected not to have a visible-light blocking filter embedded in front of the sensor. This way, I could attach my own filters of choice to the front of the camera. It had the added benefit of still allowing visible-light use when used with a hot-mirror filter.

I nearly never used this camera because it was too difficult to use. Using an external filter in an SLR meant that I was unable to see anything through the camera's viewfinder! I had to compose and focus the shot, screw on the filter, and shoot.

Last year (2006), I contacted a company called LifePixel and had them modify a Canon 20D for me (my third modified camera). LifePixel's modifications are great because they:

1. remove the camera's hot-mirror filter
2. attach a visible-light blocking filter in front of the sensor
3. adjust the firmware so focus still works accurately

How did the LifePixel-modified camera perform? Very well! I love the thing, for several reasons:

1. The visible-light blocking filter is internal, so the camera's viewfinder still works. I can shoot normally!
2. Greater choice of lenses. It is now possible to use lenses that don't support front-mounted filters (think fisheye!).
3. Very sensitive to infrared. I can shoot in infrared with reasonable exposure times.
4. Calibrated focus for infrared.

LifePixel-modified 20D

LifePixel-modified Canon 20D. It looks like a normal
camera and doesn't require external filters.

On the left, you can see the mirror of the modified camera. On the right, I've exposed
the sensor. You can see the visible-light blocking filter (looks black).

White-balance

As is typical in digital infrared imagery, color images out of the camera don't always look right. I'm not sure what filter LifePixel uses, but when used with the Canon 20D, it produces very "red" images when using any of the default white-balance settings. A custom white-balance of 2000° K and a tint of around -63 gives you white whites and produces a sepia-toned image. I suggest a conversion to black & white in whatever software you use for image processing.

Left: image converted to black & white
Right: image out of the camera, with custom white-balance

Focus

LifePixel says, "We adjust the auto focus and can attain f/2.8 accuracy in most cases. For Canon SLR cameras the lens we calibrate to is the 50mm 1.8 lens and for Nikon SLR cameras we calibrate with the18-70 AFS DX lens." They will calibrate your camera to a specific lens, if you ask them to.

My camera seems to focus well. I attached a 100mm macro lens and snapped some photos focused to the 3" mark on a metal ruler @ f2.8. All of my shots seemed just slightly back-focused, but are acceptable.

Two shots of a ruler, focused to "3"

Sharpness

Below is an image I shot of my bookcase (with a tripod) at f11. I have blown up four 500-pixel sections to 100%, so you can see how the camera performed. RAW conversion was done with Apple Aperture with standard sharpening.

Summary

I highly recommend LifePixel for infrared camera conversions. I should disclose that LifePixel did my conversion for free in exchange for a write-up, but I hope that the images here speak for themselves. Those of you who know me know that I do not skew my results based on getting something for free!

More Examples

Fish-eye in near-infrared, taken with a LifePixel-modified Canon 20D

A winery in Napa in near-infrared, taken with a LifePixel-modified Canon 20D

Sunglasses look transparent in infrared