Is it possible to do infrared photography with digital cameras?

The Sigma DSLR cameras do straight IR work without long exposures or altering the sensor – all you have to do is remove the dust protector (which takes a moment and requires no tools, and is easy to put back).

At that point you can do what is called a full-color IR where you capture the other portions of the spectrum but extend into IR, or you can use an IR-Cut filter like the Wratten filters (87b being an example of that). I have a Cokin-P filter holder, that I use with an IR-Cut Wratten gel – that way I can frame and focus and quickly drop the IR filter down into place before shooting.

You can find a number of images taken with an older version of the Sigma DSLR here:

http://www.pbase.com/sigmadslr/all_infrared

An Example:
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