WHEN Giovanni Piranesi changed the Italian title for his series of prints depicting fanciful prison scenes to the double-entendre "Prisons of the Imagination" (an earlier version corresponded, roughly, to the more straightforward "Imaginary Prisons"), he left the door wide open for Vik Muniz to walk in.

Muniz -- who, it has been said, doesn't so much make pictures of things as pictures of thoughts, and in whose quasi-conceptual art it is sometimes easy to get lost -- is a perfect kind of after-the-fact collaborator for the 18th-century architect, etcher, archaeologist, designer and theorist. In a way that Piranesi surely never intended, Muniz has created a response to the centuries-old etchings that takes their title quite literally, as spider webs in which the imagination of the viewer gets wickedly, wonderfully stuck.

Both Piranesi's etchings and Muniz's witty take-offs of them -- photographs of meticulous, 3-D pin-and-thread re-creations that ape the etcher's black marks on paper -- are on view at the National Academy of Sciences.

Muniz's work has been called the result of an "unlikely encounter" between draftsman and photographer. Known for making almost sculptural renderings of two-dimensional pictures using such unorthodox drawing materials as blood, chocolate syrup, wire, sugar, M&Ms and gingerbread -- and then photographing the results -- Muniz is less interested in showing off his often virtuosic gift for mimicry than in what that gift can tell us about the way visual culture works.

From a distance, his pictures often look close enough to the original to fool the eye utterly, even when the original itself has been distorted through reproduction or enlargement. Mounting the stairs to the National Academy of Sciences gallery, for instance, it isn't immediately obvious which are his works and which are Piranesi's.

Upon closer inspection, however, it's quite clear what Muniz has done.

For one thing, the heads of the pins he has used to anchor his obsessive-compulsive threading glint metallic in the oversize photographs. For another, the twist of the thread's black braiding itself catches light, turning Piranesi's flat etched lines and rich black shadows into a network of crisscrossing tightropes and looping skeins that hover a centimeter or two above the paper. It's as if he has unraveled, and then redrawn, the picture -- with just enough attitude to make you notice something's not quite right.

Of course, what Muniz wants you to notice is not his virtuosic technique alone, although there is real pleasure to be taken in his skill. He's primarily interested in making you feel Piranesi's art and the process behind it, even as you raise questions about how we extract meaning from it.

First, there's the trick of vanishing-point perspective, which Muniz exposes as merely a construct of lines, seducing us into believing in it. But there's also the work's implicit narrative, which Muniz explodes to reveal several simultaneous "micro-narratives," all occurring simultaneously and including not just the explicit content of the image but the narrative of the work's own making. Never forget, Muniz reminds us, that in looking at one of his finished pieces, we're looking at a photograph taken of a sculpture based on a print (or, more likely, a reproduction of a print) made from a plate into which lines have been etched in the mirror image of a scene -- a scene, needless to say, that exists only in the head of the artist.

Talk about prisons.

What Muniz draws our attention to, in the final analysis, is not art in itself but the belief system that art entails. Isn't it, after all, a kind of faith on our part that allows our minds to "read" an image as anything other than a jumble of black lines?

What allows the eye of the viewer to extricate itself from the prison of the picture plane is the belief that an engraver's mark, a stroke of paint, a halftone dot or pixel makes some kind of sense. And that is, in the end, liberating.

GIOVANNI PIRANESI AND VIK MUNIZ: PRISONS OF THE IMAGINATION -- Through Dec. 31 at the National Academy of Sciences, Upstairs Gallery, 2101 Constitution Ave. NW (entrance at 2100 C St.) (Metro: Foggy Bottom-GWU). 202-334-2436. www.nationalacademies.org/arts. Open Monday-Friday 10 to 5. Free.

From the National Academy of Sciences' "Prisons of the Imagination": Giovanni Piranesi's 1780 etching "Arch With a Shell Ornament" . . . . . . and Vik Muniz's response: "Arch With a Shell Ornament After Piranesi."