A stark blue hue illuminated a crowd of faces as the lights dimmed in Theatre 1 at Coolidge Corner Theatre.
On the screen, waves crashed over a submersible bobbing on the ocean surface, ready to descend 3,000 feet.
For the next 90 minutes, “A Life Illuminated” unveiled the story of the trailblazing marine biologist Edith Widder, in her lifelong journey to understand the language of light found in the depths of the sea: bioluminescence.
“A Life Illuminated,” directed by Tasha Van Zandt, opened the 11th year of the GlobeDocs Film Festival Wednesday night. Thirty films will screen through Sunday around Greater Boston and online as part of the festival hosted by Boston Globe Media.
After Wednesday’s screening, Widder, Van Zandt, producer and cinematographer Sebastian Zeck, and Boston Globe Media’s CEO and co-owner, Linda Henry, stuck around to discuss the film and answer audience questions.
Widder, 74, who grew up in Arlington and graduated from Tufts University in 1973, first took to the deep sea in a diving suit called the WASP. In her first open ocean dive, Widder turned off the lights and was met with an explosion of bioluminescence akin to a Fourth of July fireworks display, she said.
“I was 800 feet down, turned out the lights, and I was just surrounded by this most astonishing light show you could ever imagine,” she said. “It was just breathtaking.”
This bioluminescent display, known as the flashback phenomenon, has since led her research. “A Life Illuminated” explores Widder’s goal to film the phenomenon in the deep sea.
Van Zandt said she chose the topic of the film after her first conversation with Widder.
“I learned all about the rest of her life and her journey, and learned about this language of light in our oceans,” Van Zandt said. “And I realized that she is the story.”
Filming 3,000 feet below the surface was no easy feat, Zeck said. The process required Van Zandt and Zeck to travel in a second submersible alongside Widder’s, dedicated solely to filming.
Systems engineer Sean Hogarty, 54, attended the screening to better understand the technology behind filming bioluminescence.
“I just found it really motivating as an engineer, to see people understand what comes out of the years and years and years of investment and time,” Hogarty said.
For Van Zandt’s mother, Milena Gross, her daughter’s journey to the deep sea sparked a mix of nerves and excitement.
“I told Tash, ‘You got this,’ and as nervous as I was, I was also so very excited about this incredible film that she’s making,” Gross said.
After her fourth viewing, Gross’s favorite part is “more of a feeling,” she said. “It’s walking away thinking everything is possible.”
UMass Boston students and friends Dee Brooks, Ora Kerr and Emma Van Zandt, Tasha’s sister, felt a similar sense of inspiration after watching the film.
“I really appreciated going through her younger years,” said Brooks, 21.. “It was really inspiring to see her kind of grow into the person that she is right now.”
Widder’s excitement and love for discovery were “infectious,” Kerr said. “This was incredible. I was blown away.”
For Emma, the experience was “super exciting,” having watched Tasha’s work take shape.
“I am so proud of her,” Emma said. “I think that it’s been a weird, wonderful journey watching her get to be able to do this.”
Up next for Van Zandt and Zeck is an impact campaign they are launching alongside the Ocean Research & Conservation Association (ORCA), Widder’s nonprofit organization dedicated to protecting and restoring aquatic ecosystems.
Widder hopes that after watching the film, people are inspired to bring back their sense of exploration, to “give them a sense of empowerment,” she said.
“I’d like the largest takeaway to be people tapping into the need for us to explore our own planet,” Widder said. “That sense of who we are as explorers. That is who we are.”
This article is part of a partnership between Brookline.News and the Boston University Department of Journalism.
This article was originally published on October 24, 2025.



