THE DEVELOPMENTAL BUTTON RULE. At SeaLife Cameras in Moorestown, New Jersey, that’s what they call the guidelines for how simply a camera’s features need to operate. ¶ “Our lighting has one button — you control everything with it,” says Sven Harms, the company’s vice president. “Our cameras usually have three buttons, and our most sophisticated camera has four buttons and keys. That’s it. We figure that if you have any more than that, it’s too specialized.” ¶ The company got its start in 1995, when film was dying and digital technology was evolving. By the late 1990s, SeaLife had developed an underwater digital camera. ¶ “We had a 1.3-megapixel camera,” he says. “That was a big deal back then. It was very low resolution, but it worked, and it was…