Such moments are mistakenly labeled "ordinary," Carbajal says. He considers them small miracles.
Carbajal, this year's artist-in-residence for Medicine X, has Amyotrophic Lateral Sclerosis (ALS), a progressive neurodegenerative disease also known as Lou Gehrig's. He knows he won't be taking photographs forever. Too soon, the day will come when he can't go outside anymore.
In preparation for that day, he gathers images. So far, he's taken some 50,000 of them, traveling around Redlands, Calif., in his wheelchair, using his shoe to click the camera's shutter release button.
Carbajal has received attention for his advocacy efforts: A video he made during the viral Ice Bucket Challenge, in which people dumped buckets of ice water on their heads to raise awareness about the condition, has been viewed 17 million times. He has appeared on Ellen a few times.
His photography is a quieter pursuit. His pictures reflect his optimism, resilience and strong will to live.
Long before he was diagnosed with ALS three and a half years ago, at age 26, Carbajal was intimately familiar with the disease's excruciating toll. His grandmother had the condition. His mother has lived with it for 15 years.
Carbajal first got into photography in high school -- he started offering a class at the local Boys & Girls Club. After he graduated from business school, he took a job as a wedding photographer so he could take care of his mother while he worked. She sat next to him and helped edit photos.
When Carbajal started getting tired during gigs, he initially chalked it up to a busy schedule. Then his hands started shaking, and he needed to ask his assistant to help button his shirt. In January 2014, he received the devastating diagnosis. He wept, then worked up the courage to tell his mother.
That day, he dropped photography, emailing 26 brides with the news. But he felt lost. If he wasn't a photographer anymore, who was he?
A few months later, he "MacGyvered" a wheelchair with a cable that lets him take pictures with his foot, since his hands have less strength than his legs. He carries a speaker, a water pack and a breathing machine, rolling along until he can't breathe anymore, or until the battery dies on his wheelchair or camera.
The wheelchair, he says, helps him break boundaries.
"I fear no one and no one fears me," he says. "It allows me to be very intimate with everybody I encounter. I hate to say this, but it's such a privileged perspective."
He finds beauty in every gritty alley, at all hours, and with all kinds of subjects. He feels comfortable approaching people who once intimidated him -- those who struggle with addiction, or criminal backgrounds, or homelessness. Almost always, they are grateful to find someone who listens to them.
"I have a disability that is obvious," he says. "But there are so many people who are carrying a heavy weight."
When he rolls out of the house at 1 AM, his wife, Laarne, worries. But he feels no fear. People, he says, are extraordinarily gracious.
"I almost feel guilty because I am hogging all the kindness," he says.
When he can't move fast enough to photograph a scene, he instead commits it to memory. He keeps a running list.
Carbajal is working on a book of his photographs, and is being featured in a documentary about his life. Recently, he held a show in an alley near his house. Visitors were welcomed to take home any print that featured them.
"I'm trying to show the world that life doesn't have to end with ALS," he says. "You can still have a meaningful life with this disease."
Carbajal will be a speaker at the Stanford Medicine X conference, which is happening later this week.