It’s tough to look through Jeffrey Stockbridge’s “Kensington Blues,” an online photo series he created over five years documenting the people who frequent Kensington Avenue — many of whom are drug-addicted or homeless.

It’s tougher to hear the subjects of Stockbridge’s photos speak about their addictions — the reasons why they’ve resorted to prostitution, their feelings about the state of their realities — which they do in audio recordings featured on the site.

It’s tougher still to watch them grapple with these things, to watch them actively engaging in their drug use. They do so in “Surviving Kensington,” the documentary that follows Stockbridge as he shoots his haunting photographs along the Ave.

Stockbridge recently posted that documentary, made by Brooklyn documentarian Mo Scarpelli, to the “Kensington Blues” site as promotion for the pre-sale of a book of his portraits scheduled to be released this spring.

Ten percent of all sales will be donated to Prevention Point Philly, a Kensington nonprofit that offers HIV and hepatitis C testing, syringe exchange and other services.

“I want to give back to the community who helped me create this project,” Stockbridge wrote in an email. “PPP offers a wide variety of much needed services in the neighborhood. They focus on harm reduction and welcome anyone in need without judgement.”

It’s no secret that Philadelphia has a massive drug problem, much of which is concentrated in the Kensington neighborhood. Can the public’s awareness of it change anything? What does it mean to know the names and faces of Philadelphians suffering from addiction? Is it even ethical to show them in such vulnerable circumstances?

“Kensington Blues” doesn’t seek to answer these questions. It does do something important, though: It demands the viewer’s empathy.