During autumn, the leaves of many of our deciduous trees change color before falling off and dying. Sad, right? It depends on how you look at it.

Owen Reiser—a very patient mathematics and biology student at Southern Illinois University Edwardsville—spent more than a month filming the color-changing process to create an ambitious, two-minute time-lapse video featuring close-ups of leaves transforming from yellow and green to red and brown.

“I was taking a field biology class and we were learning about deciduous trees,” Reiser told Smithsonian. “I’ve been getting into wildlife photography and time-lapse for a while, and I couldn’t find a time-lapse of leaves changing color, so I just went for it.”

It took Reiser six weeks—and many sleepless nights—to compile the footage. He snapped more than 6000 close-up photos of leaves, including images from 10 different Midwestern deciduous trees, such as sassafras and sugar maple. He took a photo of each leaf once every 30 to 60 seconds for three days using a camera, a LED light, and a battery that allowed his camera to run constantly. “It’s [basically] a cardboard box and a bunch of duct tape, but it gets the job done,” he said.

You can see the green and yellow leaves quickly fill with reds and browns; new colors dramatically take over, and pigments break down. It looks like “dye spreading through fabric,” according to Smithsonian.

But what occurs when the leaves alter color isn’t so simple. “People argue that the red color is [also] an unmasking from the breakdown of chlorophyll, and that’s simply wrong,” David Lee, professor emeritus in biological sciences at Florida International University, told Smithsonian. “The red color is actually made when the chlorophyll is beginning to break down—there’s a synthesis of those pigments, so it’s quite a different thing.”

Either way, after watching the video, you'll never look at fall foliage the same way again.

[h/t Smithsonian]