reflex camera

A reflex camera uses a mirror to reflect the image from the lens onto a ground-glass screen. This allows the photographer to see the image exactly as it will appear on the film, enabling precise focusing and composition.1

In a single-lens reflex (SLR) camera, this mirror is positioned at a 45° angle and moves out of the way when the shutter is released, allowing light to reach the film. This temporary movement causes the image to disappear from the viewfinder during the exposure. Modern SLRs often incorporate built-in light meters for accurate exposure settings, with some using through-the-lens (TTL) metering to account for various photographic factors.23