Smaller cameras, like interchangeable-lens compacts and traditional compacts don't have the mirror for protection, though. Same thing goes for your DSLR if you have it set to liveview mode. Those cameras use the sensor to give you a preview image, so if the sun is in the frame, it's being channeled through the lens and right at your chip. It's easier on your eyes, but a lot tougher on your gear. Leave it on long enough and you could easily cause things to overheat, especially if you're shooting on a day when it's already hot out.