Next fall Americans will get their first peek at what is probably the world's largest contact-printed photograph of one of the world's most famous and controversial paintings taken with one of the largest box cameras over constructed.

All of which may be Guinness Book of Records fascination to some, but for the art world the feat by The Polaroid Corporation has greater significance. The photograph, about 13 feet high by 9 feet wide, is said to reproduce Raphael's "Transfiguration of Christ" in better detail than the original can be viewed where it hangs in the Pinacoteca, a Vatican gallery.

"The Vatican asked that we do this," said Sam Yanes, a spokesman for Polaroid. "They don't like to talk about this much, but there has always been some question about whether Raphael or his students finished the painting. They wanted this replication to send to scholars. They didn't want a lot of scholars on ladders all over the place trying to see the painting at the Vatican -- it's difficult to see there anyway."

Using stock Polacolor 2 film on a roll about 40 inches wide that is typically sliced up at Polaroid's manufacturing center into sheets of film for common instant cameras, technicians cut the film into strips about 10 feet long, made four horizontal exposures of the original painting, pressed the film sheets together for developing with specially ground rollers, and 60 seconds or so after each exposure stripped back the covering to reveal final prints. The four prints were then butted to each other to make the final reproductioin -- 95 percent of the size of the 13 1/2-foot by 9 1/4-foot original.

The project, undertaken at the Vatican about a year ago, took several weeks to complete, much of the time spent constructing a 20-foot by 20-foot by 23-foot camera out of steel tubing and then covering it with black mylar plastic held together with black tape. A specially made lens was mounted on an adjustable hydraulic platform at the front of the camera. The lens itself weighs more than 50 pounds, is nearly 15 inches long, more than 9 inches in diameter and has a focal length of about 6 1/2 feet. The inside of the homemade box camera could accommodate 30 to 40 technicians and observers. Workers inside the camera painstakingly focused the exposures by moving the giant sheets of film to precise positions.

The negatives for the four-part final composite print were the same size as the prints, a process called contact printing, which happens to be the process instant cameras use. "The whole point of the shooting was not to have an enlargement," Yanes said. "When you blow up a photo, you see the defects in the negative." However, Polaroid technicians did make some detail magnifications at three and five times the size of the original for scholars.

The "Transfiguration," painted in the 16th Century, was restored in the mid-1970 by the Vatican, which removed centuries-old varnish and dust, allowing the Polaroid print to reproduce details the painter had left unfinished.

Polaroid dismantled the camera, the strobe lights and the lens apparatus after the Vatican shoot, but a spokesman said the company would consider repeating the process if requested by a museum.

Yanes said Polaroid has not made such art reproductions with marketing in mind. They were, simply, experiments. "We learned we could do it," Yanes said. "We learned the process is indeed useful for scholars and that it is a respectable process. We can produce a print as enjoyable to the eye as the original artwork."

The print of Raphael's masterpiece, as well as the magnifications, will be on display at Harvard University's Fogg Museum in Boston next fall, and may go on a nationwide tour later.