The "pod machine" sits on one side of a crowded room in a renovated mill in Putnam overlooking northeastern Connecticut's Quinebaug River. It has dials, lights, buttons, wheels, levers, greasy cranks and even a flashing red light on top. When the blinking stops, this most retro of contraptions is ready to do its part to help save a most retro form of photographic art.

We're talking Polaroid instant pictures, but not little snapshots cranked out by the handheld jobs produced by the millions during the second half of the last century.

These unique instant photos are huge, 20x24 inches, taken with massive cameras that look much like those Matthew Brady and his assistants used during the Civil War. They stand taller than a tall man, and their devotees insist they produce prints of an artistic quality that surpasses even the most modern digital cameras.

Artists like Chuck Close, Julian Schnabel and Hartford-based photographer Ellen Carey have all made work using the 20x24 Polaroid.

"It imparts a tremendous amount of detail to the final print," says John Reuter, a New York City photographer who is a key player in the campaign to save this extraordinary photographic system.

It's all part of a growing retro movement that encompasses everything from vinyl records to typewriters, celluloid film to snail mail — evidence of a desire by many anti-digital enthusiasts (or nutcases, depending on your point of view) to embrace older, precomputer technologies. And Polaroid, a process that almost went extinct when the company went bankrupt and its intellectual properties and equipment were sold off a few years ago, has now become something more than a cult phenomenon.

Andy Warhol was a big Polaroid fan, as were many other major artists in the 1960s and 1970s. Earlier this year, Lady Gaga unveiled a new Polaroid instant camera she helped design. There are Polaroid-style photo apps for cell phones and websites that will turn digital shots into mailable Polaroid-style prints.

"Retro is big in this country right now," says Ted McLelland, a 71-year-old former Polaroid researcher and production expert who now helps operate the nearly half-century-old, one-of-a-kind pod machine. "I think there's an artistic need for it too."

The pod machine is what takes the necessary chemicals and seals them in "pod" strips to be used in the few remaining 20x24 cameras. One of those massive, 240-pound, leather, wood and metal monsters stands on its tripod a few feet away in that old Putnam mill room.

Another of the big cameras is in Reuter's 20x24 Studio in Manhattan. Another is in Cambridge, Mass., and another in Europe. McLelland says there are several nonworking versions of the cameras owned by people around the country, and that two new ones are now being built in California.

These big beasts were created in the mid-1970s and their first job was to record paintings at a Boston museum. Polaroid offered several for use by art photographers, who fell in love with the quality of the prints they produced.

"It was a preposterous leap forward," Reuter says of the remarkable size of the 20x24 prints.

McLelland worked on research with Polaroid inventor Edwin Herbert Land, who was born in Bridgeport. Land developed the supersized cameras and the specialized film and chemical processes, and later helped provide technical support for photographers like Reuter, who was another longtime Polaroid employee.

Modern digital imaging "is too perfect," McLelland says. "It's wonderful, gives great color ... but it isn't art, it doesn't have the subtleties of art." He argues that the 20x24 photo process and film "equals the subtleties of painting, with all of the hues, all of the flaws of painting."

When Polaroid went belly-up and the pieces of what remained started being sold off, Reuter found some backers who put up the money to buy the cameras, the pod machines and assorted other essential equipment, and inventories of film and chemicals.

Reuter was able to install a "very sophisticated mixing vessel" to prepare the chemicals used in the Polaroid process in one corner of a Dudley, Mass., chemical company. A few miles down the road in Putnam, he found the old thread mill that would become the home of the pod machine.

A resident of Longmeadow, Mass., Reuter said he was looking for a location that was close enough to Boston and New York, and not too far from his home and those of his former Polaroid colleagues (like McLelland) who had agreed to help out on what they called the "Impossible Project."

McLelland said the pod machine was built in 1963, "the year I started at Polaroid." Its complicated system of tubes, pumps and other devices takes the chemicals and inserts them into 20-inch aluminum foil "pods" and seals them. The pods go into the cameras and exude the developing chemicals onto the film.

The Putnam mill also houses a "negative spooler" used to roll up the film to the proper lengths to be used in the cameras. The film-paper becomes the print. The spooler is even older than the pod machine, according to McLelland, and "may be older than Polaroid itself." He says it originally came out of an old textile factory where it rolled up cloth for transport.

The former Polaroid employees who have banded together to help preserve this photographic system and these fragile machines have clearly fallen under the spell of this last-century-technology time machine.

"There's a little cult thing to it," says McLelland, "like an antique-car club to an extent."

Reuter took one of the cameras to London this summer for a shoot. These photos have developed a worldwide following. In the 20x24 Studio in NYC, stars like Clint Eastwood and Matt Damon stop by to have celebrated photographers record their images.

According to Reuter, there's nothing else that can quite compare. "The sense of detail and tonal transition is still unique," he insists.

Fairly soon, Reuter and McLelland and their colleagues will gather in that Putnam mill room to turn out another batch of those essential, chemical-filled pouches.

That's when the red light will stop flashing, the cranks begin to turn, belts and wheels to spin, and the pod machine will once more try to turn back the hands of time.