While other kids in Dayton, Ohio, were playing hide-and-seek, shooting hoops and spiking the pigskin, Kenneth Marlow spent endless hours sketching close friends and strangers worthy of his notice.

"I had a narrow outlook," says Marlow, now 25. "The only thing that interested me was how people looked and their features. I wanted to show their personality through my work."

Fourteen years and scores of commissions later, Marlow is still pursuing the art of portraiture, now from an F Street NW studio in downtown Washington's LeDroit Building. This summer, his nude self-portrait oil won the National Art Competition at New York City's Grand Central Art Galleries, sponsored by American Artist magazine. He won the $4,000 prize over more than 6,000 entries from around the country. Marlow's work is shown at Jane Haslem Gallery at 406 Seventh St. NW, and he has been invited to be represented by Portrait Galleries in New York.

Like an altar amid desolation, his 10-foot antique German oak easel stands in his third-floor studio, surrounded by broken frames, tattered cloth sofas and walls smeared with creative graffiti and hung with his collectible true-to-life portraits.

When Marlow's not there working on a commission, he's often on the second floor in the studio of Frank Wright, a George Washington University drawing instructor whom Marlow studied with when he was a teen-ager. Marlow is painting Wright's portrait.

"Ken has an extraordinary gift for observation," says Wright. "At 17 he could see subtleties and capture nuances which constantly amazed the class and exceeded all my expectations."

The canvas is positioned near the window of Wright's studio, facing the F Street corridor. The slightly larger than life-size painting seizes the attention of passers-by and friends, who sometimes wave their hands frantically, thinking it's Wright gazing out toward the National Portrait Gallery.

For hours on end, Marlow is poised before the easel, predictably stroking the canvas as if he were lost in the offbeat disco music filling the studio. But Wright's image is gradually being extracted and transferred to the stretched parchment. An occasional pat on the head of his Jack Russell terrier, Popover, nestled in the corner, steadies Marlow's hand just enough to help him glide through the tough spots.

"Nine years ago, when Ken was a student at Hayfield Secondary School in Alexandria, he painted me with glaring features," says Wright. "At the time I was not ready to accept the toll the passage of time takes on the body. Now I can accept the down-to-earth truth of my physiognomy, and I believe this work compares favorably with past portraiture."

In Marlow's freshman year at Yale, he became dissatisfied with the painting department at the university. He changed his major to art history, in which he earned a BA in 1982.

"They wanted me to add more of a modern or abstract flavor to my painting. So I decided not to remain in the painting program but rather concentrate on the academics and continue doing what I had been doing for years," Marlow says.

After graduation, Marlow tried specializing in male nude compositions, but it didn't bring him the fame or commissions he desperately needed to survive in portraiture.

"At the time when I concentrated on selling male nudes it was very difficult," says Marlow. "Possible buyers, who mostly were men, would feel very uncomfortable just to look at the portrait. Now I spend some of my spare time doing male nudes and most of my commission work is doing various sizes of figures."

Marlow first came to the Washington area as a teen-ager when his father, who was in the Air Force, was transferred here. The family now lives in Jackson, Miss., but Marlow returned here a little more than two years ago. For nearly two years he lived and studied with Danni Dawson, an Arlington artist who is also an internationally known figurative painter. There he absorbed the flawless techniques from original works of portrait artists Burt Silverman, Nelson Shanks and sculptor Bruno Luchesi.

"What sets Kenneth apart from other painters is that he has successfully managed to learn and do at a very young age what most painters do when they are in their sixties and seventies," Dawson said.

Marlow's early success also can be attributed to help from the eccentric Shanks, who is considered one of the most successful portrait painters in America. In his Chelwood Estate in Andalusia, Pa., Shanks opens his doors and vision of portraiture to gifted young artists such as Dawson and her prote'ge' Marlow. In exchange for Shanks' fine-tuning Marlow's eye for figures and flesh tones, Marlow stretched Shanks' canvases, washed dishes, cleaned the mansion and served at cocktail parties.

Now that Marlow is securely settled in the Washington art community, he says he plans to remain in the District and hopes his presence will attract more attention to local painters and their work.

Unlike most beginning portrait artists, Marlow, who charges $3,000 to $7,000 for his paintings, refuses commissions he feels aren't suited to his particular style.

"I do only the paintings that I think are important to me," Marlow says. "I want to be able to be the best painter I can be, and that's what makes me happy."