Fabrizio's Digital Camera Project 3. How to Make Near-Infrared Images with a Digital Camera

Fabrizio

Italian photographer Fabrizio has devised some very clever ways to increase the versatility of his favorite camera, a Casio Exilim EX-Z120. This 7-megapixel camera has minimal shutter lag, an excellent menu system and is powered by rechargeable or standard AA-cells. Fabrizio's methods can possibly be applied to other cameras, so here is the second in a series of projects from Fabrizio's Casio Extreme web site. Editor.

This series of projects describes how you can expand the versatility of the Casio Exilim EX-Z120 and possibly other digital cameras.

The CCD and CMOS arrays that function as the image sensors in digital single image and video cameras are made from silicon. This means that they are very sensitive to invisible near-infrared light in the range of 750 to 1000 nm. The image sensors of digital cameras are equipped with near-IR blocking filters to prevent interference from these wavelengths. Nevertheless some IR leaks through.

Here the ingenious Fabrizio shows how to make a simple filter that blocks visible light while passing near-IR in order to transform some digital cameras into near-IR cameras. The filter is shown in Fig. 1.

The near-IR filter is cut from an exposed piece of developed, black slide film. Kodak films will work, but Fuji is best. The filter is attached over a hole cut in the lid of a 35-mm plastic film container. The completed assembly is held in place over the camera's lens or temporarily secured in place using tape or Velcro.

Caution: This near-IR filter may work much better with some cameras than with others. Always use care when placing an object over or near the lens of a digital cameras. These lenses are very fragile, and their focusing mechanisms are easily damaged or broken. For these reasons Fabrizio and The Citizen Scientist cannot be held responsible for your results and any damage to your camera. Editor.

Figure 2 is one of Fabrizio's fine near-IR photographs made using his near-IR filter and a Casio Exilim EX-Z120. The filter should work with other cameras, and a trial and error procedure will be needed to find out.

This project has many scientific applications. Readers who assemble a near-IR filter modeled after the one designed by Fabrizio are encouraged to submit sharp sample photographs for possible publication in "Backscatter" or "Gallery." Send your contributions, a detailed caption and your name here. Editor.