The Chelsea Museum’s “It’s Not a Photo” is an eccentric exhibition that presents a curiosity chest of photographic possibilities.The artists on display carry the notion of photographic abstraction to its logical extreme. Not only are their images nonobjective; many were made without a camera, using only light, photographic paper, and darkroom chemicals.

The results of such experiments can be surprisingly decorative. Wolfgang Tillmanns, the most famous artist in the show, is best known for figurative photography, but he has also dabbled in abstraction. His three “Mental Pictures” (2000) are chance darkroom creations, in which passages of brilliant color — blue, yellow, and green — share space with the unexposed white of the photographic paper. Calm, warm, and gently seductive, these enigmatic works feel like watercolor doodles.

The images in James Welling’s “Degrade” series (1985–present) are also cameraless exposures.The artist places photographic paper beneath an enlarger, which serves as the light source, and by slowly moving a piece of cardboard to generate shadows, he creates subtle variations of brightness and tone. Several of the resulting images contain two or three stacked blocks of color and resemble the iconic paintings of Mark Rothko.

The allusion to Rothko is intentional: His color-field abstractions — and modernist painting more generally — serve as historical antecedents for these photographic experiments. But if Mr.Welling wishes to suggest the avantgarde import of his work, he overreaches. There is a crucial distinction between abstract paintings of the 1940s, ’50s, and ’60s and these photographs. The former laid bare the techniques and materials associated with easel painting, exposing the essential nature of pigment, brushstroke, canvas, and frame in works that emphasized the process whereby art is created. In the action paintings of Jackson Pollock, for instance, process and product seem to merge on the surface of the canvas.

These photographs have almost the opposite effect. They turn the camera into an object of obscurity and portray the darkroom as a place of mysterious alchemical experimentation. Whereas modernist painting was explicitly accessible, these images conceal their means of production and show little interest in gesturing to a wider, lay audience. And unlike modernist painting, which influenced all subsequent work in the medium, these photographs will be no more than footnotes of art history.

Marco Breuer seems to be well aware of the esoteric nature of his photographic oddities.The artist’s two “Pan” images (2003) place densely packed patterns of differently colored horizontal lines before a black background. The title references the horizontal sweep of a movie camera.These curious images, which Mr. Breuer created by scraping Chromogenic paper with a razor blade, look something like scientific charts whose intricate patterns, though illegible to the nonspecialist, exert unexpected aesthetic appeal.

Similarly alluring are several photographs from Dimitrios Antonitsis’s “Philosophobia” series (2004) and the digitally generated art of Jeremy Blake and Willa Davis. “It’s Not a Photo” is an exhibition without masterpieces. And yet, with a few exceptions, these works are attractive, serene, and intimate, offering subtle pleasures.

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After “It’s Not a Photo,” the photographs on display in Baumgartner Gallery’s survey of the 2006 Yale MFA graduating class will seem familiar and, to the average viewer, more satisfying.There are several talented artists here and some will no doubt be heard from in the near future.But overall,this work betrays its origin as student production. The photographs are uneven, somewhat unpolished, and occasionally derivative; a few too many are oneliners.

Jenny Drumgoole’s rambunctious, over-the-top video,”Husky” (2006), will initially grab your attention, if only for its loud soundtrack and antic sensibility, and she may well be the first of her class to win wider recognition. Her photographic stills, which are not in the show but can be seen in a catalog of the students’ work, are quieter than the video but just as funny.

I was also impressed by the work of Daniel Gordon, whose photographs of 3-D sculptures made from other photographs display a devilish sense of humor, and Marisa Baumgartner, the gallerist’s daughter. Ms. Baumgartner’s “Visible City (Obstructions V)” (2006) presents an attractive, hazy vision through a car windshield and is one of the few images here that gestures toward the sort of abstraction seen in “It’s Not a Photo.”

The most moving work in this exhibition is also the most personal. Colin Montgomery’s portrait of his mother, “Untitled (Marilyn)” (2005), views its subject from behind. The skin of her neck and cheek is loose and dappled with the red splotches of aging. Her silvery-white hair, interlaid with the occasional black strand, is so thin in places that it looks like a diaphanous shroud barely covering the pale skin of her scalp.

Alison Sexton’s “Untitled (Davy)” and “Untitled (Funeral Flowers)” (both 2006) also relate to a family member, in this case, the artist’s brother. The first photograph shows the young man in profile from the waist up, his hair and white shirt damp, presumably after a swim in the deep blue water that constitutes the picture’s background. The second portrays a pile of funeral flowers, their yellow buds the image’s only bright color, lying atop a thick tangle of fallen branches, leaves, and snow. The arrangement resembles a funeral pyre, suggesting that this somber winter image needs only a spark to transform into a blazing flame. The image’s tension between cold melancholy stillness and fiery explosion perfectly captures the dual nature of grief for the passing of someone so young.

“It’s Not a Photo” until August 26 (556 W. 22nd Street, between Tenth and Eleventh Avenues, 212-255-0719). Yale MFA until July 19 (522 W. 24th Street, between Tenth and Eleventh Avenues, 212-242-4514).