Video-Assist

A tiny pin-hole camera is mounted above the camera lens. A small battery-powered LCD monitor is attached to the camera frame (clearly visible in top-left of photo). The pin-hole camera is positioned to mimic the view through the lens as closely as possible. When the camera lens is zoomed in we mask the LCD monitor with tape to represent the new frame size. It's an admittedly crude device but with some practice we had a fair idea of what we were shooting.