Ridgefield — Kids who have grown up with sleek video technologies — such as snapping photos with their phones — got step-by-step lessons recently in the foundations of photography in Mark Cook’s class at Ridgefield High School. They built pinhole cameras from cardboard boxes and duct tape, and they took pictures by sliding cardboard shutters in front of light-sensitive paper. Everything had to be exact, students learned, from their box measurements and the duration of light exposures to the development and enlargement of photos using chemicals in Cook’s makeshift darkroom. “Exposing the scene through a pinhole and grabbing a picture is awesome,” said junior Grant Gaspar. “The most challenging part was making the box because of the precise measurements, but even that was still pretty fun.”