Q. Can you tell me the difference between high key and low key pictures? How do you take them?

A. High key and low key refer to the dominating light tones, be they light or dark. A high key photo consists primarily of light colors -- whites, light backgrounds, light clothing and very few black areas in the picture.

Low key pictures are the reverse: dark subjects and backgrounds with next to no white areas in the picture.

Light-colored high key pictures are best used in upbeat, delicate and open situations, while low key shots are somber, moody and convey an air of mystery.

When making a high key picture, make sure your lighting is soft and very full. You must pose your subject so that no harsh shadows or dark areas appear. Usually frontal lighting works best.

Outdoors, snowscapes and open field areas lend themselves well to high key shooting.

A low key picture is best made in a darkened area, with perhaps one light spotted on the subject. Try to light the subject from the side. Outdoors, landscapes just at dawn and at dusk, printed to high contrast, make wonderful low key pictures.

TOP SHOTS

Congratulations to Dave Nally for winning best of show at the Northern Virginia Photographic Society show. Jim Sollo, Erwin Siegal and Jim Dacey of NVPS organized a great show.

Congratulations, too, to Richard Monson, who makes terrific color prints and won best of show in the Manassas-Warrenton Camera Club show, and to Peggy Johnson, Jim Spor and Jim Jeckelub for their work in making the show a success.

SWAP MEETS

A number of correspondents have reported that yes, indeed, there are camera swap meets, several of which are coming up soon.

Sunday, March 23, there'll be two, one at the Tysons Corner Marriott, 8028 Leesburg Pike in Vienna, from 10 to 5. It's called the Camera and Photographic Swap Shop and Show. Admission is $3.50. For more information, call 201/533-1991.

The second is called the Barone Camera Swap Meet, and will be held at the Crystal City Holiday Inn, 1489 Jefferson Davis Highway in Arlington. Admission is $4. For further details, call 703/768-2231.

These listings were in Shutterbug, a photographic paper that was called to my attention. I found it valuable. I also suggest that you check The Washington Post's classified section, especially on Sundays, under the listing "Cameras." Swap meets are often advertised.

PICTURES AT THE POTOMAC

Outdoor photography will be the subject of the "Introduction to Nature Photography" program presented by the Northern Virginia Regional Park Authority, March 22 at 2 p.m. at the Potomac Overlook Regional Park Center. Aspiring nature photographers 12 years old and up should bring their own cameras and film to this free event. Reservations are required. Potomac Overlook Regional Park is at the end of Marcey Road, off Military Road, in Arlington. For additional information, and to make reservations, call 528-5406.