The filmmaker Errol Morris, who is making a documentary about the photographer Elsa Dorfman — besides Mr. Reuter, perhaps the camera’s most devoted partisan — said that the camera had become a character in its own right in his film. “It’s an objet d’art, with these wheels like bicycle wheels, this huge box,” he said. “When Elsa pulls the film down from the camera and cuts across it and then the photo is brought over to a table and the cover is peeled back and this image slowly appears, there’s something quite magical about it.”

Mr. Reuter said maintaining that magic has exhausted him and the two people who work with him, Nafis Azad and Ted McLelland. Together, they help operate the cameras, store the photographic paper and assemble the chemical pods, a highly complicated process accomplished with a 60-year-old machine. With no real publicity operation, the initial financial challenges of the Great Recession and prices he probably set too high, Mr. Reuter said, “the demand for the cameras really just never materialized at the levels that it did during the Polaroid years; I think a lot of people had no idea the process was still in existence.” (The camera costs $1,750 a day to rent and each exposure costs $125, down from $200 at the company’s beginning.)

Though Mr. Close and a handful of other artists, like Peter Tunney and Joyce Tenneson, still use the camera, the death of Ms. Mark last year meant that a consistent financial mainstay — and a widely respected ambassador for the camera — was gone.

“My goal is for people to use the rest of the material we have before all of it is really past its prime,” Mr. Reuter said. “It would be a shame to end that way. ” As for the cameras themselves, he said with resignation, “I hope that they go to some place like the Smithsonian or the George Eastman collection in Rochester.”

Mr. Morris, known for his own love of rapidly rarefying film stocks like 35 millimeter and Super 8, said he continued to believe that the cameras would not end up as museum pieces. “Maybe there won’t be many — and maybe there will be a time when the process goes out of existence for a while — but I think there will be people who won’t let it go away forever.”