Marsha McNeely Photography/SpecialT

For years Marsha McNeely, a professional photographer who specializes in kids and families, struggled to capture her son's true personality in pictures. "When I took out my camera, Tynan"—who is autistic—"squinted and became rigid," she says. "But I knew underneath there was a kid who loved to laugh."

With the advice of her son's therapists, McNeely, 39, experimented with ways to make Tynan, now 7, feel comfortable—like offering objects for him to hold or joking from behind the lens. "I was snapping moments where he was simply enjoying himself," she says. When it dawned on her that other parents might be struggling with the same issue, she began offering free photo sessions through online autism support groups, and soon received a flood of inquiries. One mother of a 9-year-old told McNeely that the last good photo of her son had been taken when he was 6 months old.