HEYWORTH — The temperature at which the human body functions normally is more than just a matter of degrees Fahrenheit to Richard Gray.

It's an entryway into what he calls "the sub-visible": unseen levels of physical detail not available through mere human sight.

The body's thermal standard of 98.6 degrees Fahrenheit offers Gray a window onto that detail ... one that he has appropriated on behalf of the art of photographic portraiture.

Currently, it is represented by a series called the "Veteran Portrait Project," featuring military vets living in Indiana's St. Joseph County who agreed to become subjects for Gray's thermal camera.

The goal of the portraits, he says:"To present an enigmatic trace of one's existence, personal and intimate," and, in the process, "revealing appearances that are profoundly unique and individualized."

The heat image, he continues, "suggests a metaphorical link between a life lived, and the incredible bundle of personal and emotional experiences associated with military service."

A portion of Gray's "Veterans Portrait Project" is coming to the area in what will likely be the most unique and unusual Veterans Day observance at hand this weekend.

Gray, a 1976 Illinois State University alum and current chairman of the Department of Art, Art History & Design at Notre Dame University, will host the free public showing from 1 to 4 p.m. Saturday at the Carl E. Miller American Legion Post 624 in Heyworth.

At 3 p.m., he will deliver a talk on the project.

The Heyworth showing comes courtesy of fellow ’70s-era ISU alum and close friend Tom Haynes, who had a hand in helping form the McLean County town's own art council (HeART Arts Council).

"One of our missions with the council is to make things available here that would not normally be available," says Haynes.

A perfect opportunity was the prospect of bringing Gray's veteran portraits to town, away from an art gallery environment and in the uniquely apt context of an American Legion hall.

"I get a sense that these portraits give a deeper impression of person," says Haynes of the unusual images, which are of both male and female vets of widely varying ages.

"It's a kind of soulful look at the person through features that wouldn't be visible to the eye in person. You're seeing an aura of the person, but also quite a bit of detail through the heat."

Haynes thinks the portraits can convey "a sense that this person has had a tremendous set of experiences in life ... kind of a sense of what this person has been through."

Gray's portraits have only seen in an exhibit context once before, earlier this year as part of a South Bend (Ind.) Museum of Art show, "The Art of Valor," in which student artists from Notre Dame University and Indiana University made works of art in response to the the oral histories of local St. Joseph County-area vets.

"I volunteered to make portraits of them working with the thermal camera I had been using for the last 8 to 10 years," recalls Gray. 

The veterans were intrigued by the approach, which marks the ongoing evolution of Gray's artistic investigations "using industrial and scientific image-capture technologies to re-examine the genre of photographic portrait."

Past endeavors in this field have including using microscopes to photograph human cell tissues in a pathology lab, which led to his experiments using the thermal camera to "image a sitter's likeness without the aid of conventional lighting."

Since thermal cameras are used as military tools in areas such as night vision, Gray thought it would offer an added layer of interest to his exploration of "these veterans who have experienced a range of complex experiences in life through their military service."

The veterans who posed for his portrait project span conflicts from the Korean War to the present, with each subject's image listing the tour of his or her duty in days, not years: "It's more impactful to read that somebody bad, say, 452 days of service in Iraq than 1½ years," says Gray.

The portraits were made using a Merlin thermal imaging camera, with the resulting variation in tone representing the sitter's unique heat pattern.

The images are printed on Hahnemühle 308 rag paper using Canon archival pigment inks.

Gray considers his use of imaging technologies created to support scientific and industrial as "not only trusted conveyors of information, but also as complex provocateurs that have the ability to redefine our understanding of what it means to be photographed."