"I was always told who was beautiful, and as an artist, I didn't just see beauty on the covers of magazines, I saw it everywhere," Guidotti tells PEOPLE.
Guidotti, 57, serendipitously found inspiration for a new series of portraits – and eventually a new movement – while walking in New York City.
"I saw a kid waiting for a bus near my studio, and she had albinism, and she was so beautiful, yet never, ever included in that beauty standard," he says. "I went to research albinism and was looking in medical textbooks and saw horrible, horrible medical photographs. They just emanated sadness and sickness."
Guidotti wanted to change the way people perceive those with visible genetic conditions, so he joined with support groups from around the world to form a group called Positive Exposure to photograph these people in a new light.
"The mission of Positive Exposure is to use to the arts to celebrate the beauty and richness of human diversity, to see not a disease or diagnosis, but a person," he says.
Two of the people he has worked with through his project are Jayne Waithera, who has albinism, and Sarah Kanney, who has Sturge-Weber syndrome, which caused a large port-wine stain on her face. These women – along with Guidotti – are now the subjects of the film On Beauty, which documents the struggles they have faced.
"Both of them have been tortured because of their difference in their own communities," says Guidotti.
RELATED: Jane Fonda: 'I Don't Consider Myself Beautiful'
Waithera first connected with the photographer several years ago because she wanted to start a Positive Exposure in Kenya, where people with albinism are the victims of discrimination and prejudice, and are sometimes even killed.
Guidotto met Kanney through a friend who has the same condition.
"Sarah said to me she has this technique that she's personally developed so that she doesn't have to see people staring at her birthmark – she looks down," says Guidotti. "I was just like, 'No, I want you in the sunlight, head up!" And she just responded to that."
For both of the women, being photographed was a transformative experience.
"They're these incredible, powerful women who have been held down in society because of stigma and discrimination and prejudice, who have now been seeing themselves and their beauty," says Guidotti. "It's how they've been empowered and transformed."
Guidotti hopes that anyone who sees On Beauty is equally transformed.
"[I hope it makes people] see beauty in difference and see beauty in themselves," he says. "This is to break down barriers. It really starts that dialogue about diversity, about inclusion, about beauty, and about self-acceptance."
On Beauty premieres in Los Angeles on July 24 and in New York on July 31.