Photographer David Friedman makes gorgeous mini-documentaries about inventors (32 so far), and his latest is a must-see for anyone who wonders where world-changing technology comes from. Friedman interviewed Steven Sasson, inventor of the digital camera, in Kodak’s Rochester, NY headquarters last October, and got a little “product walkthrough” of Sasson’s first working camera — which looks like a clunky ’70s Polaroid crossed with a Speak-and-Spell. But the device is undeniably beautiful in its own lumpen, personal way, and Sasson explains some of the interesting choices he made while designing it.

Sasson’s prototype had just one button on it. You’d press it partway down to power up the giant contraption, and all the way down to snap a picture — which the camera’s digital guts would take 50 milliseconds to process before sending the data to a crude memory card in the base. A big motive for this ultra-simplicity was because Sasson was mainly concerned with making the thing work at all, rather than larding it up with features right out of the gate. But to his credit, he also knew that any new, disruptive technology has the best chance at being adopted if the designer presents its functionality in the same “language” that people are used to with other devices. If an analog camera would take a photograph with one button push, why shouldn’t a digital camera do the same thing?

Sasson took his design thinking a few steps further, considering the consumer user experience of digital photography while he was still giving birth to it. When deciding how many pictures his camera could store, he settled on thirty — because the film cartridges that everyone was used to in the 1970s came in 24- or 36-exposure rolls, and it seemed like a comfortable in-between number. He also knew that memory card storage was too out-there for non-geeks of that time to understand, so he configured his camera to copy the digital information onto an analog cassette tape. It’s hard not to burst out laughing as Sasson snaps the same storage technology that once carried Bel Biv Devoe singles onto the side of his camera, but in 1975, it was an ingenious choice: physical, rugged, and idiot-proof.