"Cornell (infra) Red," a photographic exhibit of Cornell as seen in the infrared wavelength, by Kent Loeffler, is on display at Albert R. Mann Library Gallery on campus through June 30.

The exhibit features 28 infrared photographs of such campus landmarks such as McGraw Tower and Sibley Dome.

"Infrared light can be used to create beautiful, otherworldly landscape photographs," said Loeffler, a photographer in plant pathology, part of Cornell's College of Agriculture and Life Sciences. "Chlorophyll reflects infrared light so all green plants appear bright white. Blue sky contains almost no infrared radiation so it photographs as very dark. Thus an infrared photograph taken on a blue sky summer day has the appearance of being made on a full moon night in snowy winter. Very curious indeed!"

He noted that several years ago he had one of his digital cameras -- a Nikon D80 SLR -- converted to infrared sensitivity "and have been having fun with it ever since," said Loeffler. "I walk every day from downtown Ithaca to the Ag Quad at Cornell and started carrying the camera with me on these daily treks. Carrying a camera with you constantly almost guarantees that you'll never come across anything interesting, but every once in a while you get lucky. This exhibit is a collection of these lucky collisions of light, clouds, landscape and architecture."

Loeffler explains that our eyes are only sensitive to a portion of the electromagnetic spectrum. This range of wavelengths, or visible light, extends from about 380 (violet) to 750 (red) nanometers. Even though our eyes are not sensitive to wavelengths shorter and longer than this, digital sensors can record these wavelengths. As a matter of fact, he says camera manufacturers routinely place a filter on the digital sensor that only allows visible light to strike the chip. This lets the camera record colors that appear "correct" to our eyes. Several companies specialize in converting off-the-shelf digital cameras to infrared-sensitive cameras.

Light in the ultraviolet and infrared wavelengths is often useful in scientific and forensic inquiries. Infrared imaging is used to expose forgeries and counterfeits. Inks and paints have characteristic infrared reflective properties, which differ from their appearance in visible light. Infrared is also used to visualize certain human and plant diseases.

A reception will be held May 13 at 5 p.m. in the gallery, which is located on the second floor of Mann.