Why does a camera look like a camera? Specifically, why do our cameras all resemble a box with a lens on the front? The answer is film. Film cameras needed a dark, light-tight place to store a roll or cartridge of film, and it needed to put a viewfinder close to that lens to avoid parallax problems.
Now, though, with film long consigned to the novelty closet, the only restriction is that the sensor sit behind the lens. And that’s where the D-CAN comes in, with its telescope-shaped body.