Seeing the photographic images that Diane Burko, a well-known realist painter, has exhibited since she took up photography as a second medium a few years ago, I've wondered why she didn't pursue photography seriously earlier in her career, as did the realist painters Chuck Close and Eric Fischl, among others.

I'll speculate that Burko was so used to thinking of her photographs of landscapes as studies for her paintings that she didn't consider them a separate entity, or that she didn't want to draw attention away from her painting, or that the prospect of doing two things at once and doing both well was daunting.

In any case, her embrace of the new has had a salutary effect - in one of those curious twists, Burko's paintings have become increasingly expressionistic and painterly as she has been simultaneously articulating her eye through the clarifying lens of photography.

Her latest photographs, on the ground floor of Locks Gallery, take on some of the subjects she has painted - the lakes, glaciers, and mountains of Montana and Wyoming - but Burko's aerial perspective (she's looking down more than forward, as she does in her paintings) and the cropping of her images make it difficult for viewers to gauge distances, much less determine what their physical relationship might be to the landscape in question. Other than the series' title, the pictures making up "Over Montana Glacier National Park" offer no clues as to where Burko might have been to shoot these discombobulating aerial images. (From a helicopter with its door removed, it turns out.)

There are also parallels between Burko's photographic images and other forms of contemporary art and photography that I have never seen in her paintings. For instance, photographs from her "Mid Flight" series, which seem to offer a more straight-ahead perspective than the rest, faintly resemble the female silhouettes and body prints made by Ana Mendieta in sand, mud, and grass, as well as Mendieta's photographs documenting them. Burko's close-up photographs, taken in Bucks County, of the surface of water (which are something of an anomaly in this show, but representative of Burko's more intimate photographs of her everyday surroundings), are slightly reminiscent of the paintings of the British artist Kate Bright, who exhibits with Locks.

Burko is not averse to the occasional stroke of humor in her photographs, either, a quality that would never have made sense in her paintings. I challenge anyone to look at the shape of the deep turquoise lake in Water Below 2 as Burko has shot and cropped it and not see Dumbo's head in profile.

The gallery has mounted a mini-survey of Burko's paintings - new works and canvases from the 1970s - on the third floor, and it's interesting to see how long a time the mountainous landscape has preoccupied her and how her painting has shifted from a seamless, thinly painted photorealist style to her current, expressionistically handled one.

Locks Gallery, 600 Washington Square South, 10 a.m. to 6 p.m. Mondays through Fridays (summer hours). 215-629-1000 or www.locksgallery.com. Through Aug. 19.

Look closely

Peter Barberie, the Philadelphia Museum of Art's curator of photography, has lent his discriminating eye to the Philadelphia Photo Arts Center's second annual photography competition and exhibition. The nine whose work Barberie selected for "A Love Supreme" may sound like a small number to have culled from 165 entries, but this exhibition, unlike many of its kind, allows a fairly in-depth appreciation of each photographer's efforts. It's a diverse group, too, whose works run from color to silver gelatin prints, from staged scenes to landscapes to portraiture.

Among the works that caught my attention were Daney Saylor's horizontal, improbable landscapes (such as the line of palm trees in front of a line of white trailers in front of a distant mountain range in As Far as the Eye Can See); Lisa Boughter's straightforward color shots that manage to capture the quirky details of what would appear to be the least compelling sides of anonymous buildings; and recent Tyler M.F.A. graduate Emily Rooney's mysterious silver gelatin prints, including a solarized portrait that transforms a contemporary young woman into something akin to a Dorothea Lange by way of Man Ray and Lee Miller.

Philadelphia Photo Arts Center, 1400 N. American St., 12 to 8 p.m. Tuesdays through Thursdays, 12 to 6 p.m. Fridays through Sundays. 215-232-5678 or www.philaphotoarts.org. Through Aug. 27.