Cameras and Filters
Why it works
All digital cameras have sensors that are sensitive to infrared light along with the visible spectrum. Many manufacturers put infrared-blocking filters within the cameras to lessen infrared's effects. However, some cameras don't have them -- with these, you can simply attach an infrared filter to the camera and shoot infrared photos as if you would any other.
It is possible to shoot infrared photos with almost any digital camera, but ones without infrared-blocking filters (or removing the infrared-blocking filter) will have much shorter exposure times and require less editing in Photoshop. Regardless, the following steps can work for both infrared-blocking and regular cameras.
1. Finding a camera
Cheaper digital cameras are often more infrared-sensitive than upscale models. Expensive cameras, particularly D-SLRs, can be difficult to use to shoot infrared photos. The first step in shooting infrared photos on your digital camera is to determine whether it has an infrared-blocking filter.
How to test if your camera blocks infrared
An easy way to test whether your camera blocks infrared is by viewing a remote control, such as a TV remote, through your camera's LCD screen. Simply press a button on the remote while looking through your LCD screen or viewfinder. If the remote light shows up white, your camera isn't blocking infrared light.
If you can't see any infrared beam, you might have to take apart your camera to remove the infrared-blocking filter. This can break your camera and will void its warranty, so I'm not going to go into it here. Geektechnique offers a guide on how to remove the infrared-blocking filter.
You can still take infrared photos with your camera, but it might not be practical -- prepare to use a tripod and deal with long exposures and blur.
For a comparison of infrared photography with a converted and unconverted camera,check out Digital ImageMaker's guide.
2. Finding a filter
Which to use
Typically, digital cameras require darker filters than shooting infrared film. A No. 25, a medium red filter that allows some visible light, will not produce as dramatic results as it does with film.
I suggest testing out different filters. A camera that does not block infrared light will not need as dark a filter as one that blocks out most infrared light. Here are the two "classic" filters:
- No. 89B: This is the most commonly used filter. It will produce a dramatic infrared effect in most cameras without requiring huge exposure times.
- No. 87: This is a more intense filter. It is opaque enough to prevent photographers from seeing the shot in the LCD screen. However, it produces a strong infrared effect and works will with cameras that block a lot of infrared light.
Fastening the filter
Once you find a filter, make sure you have some way to fasten it. If you can't screw on a filter to your camera, cut the filter and tape it in place or simply hold it up when you're shooting.