Characteristics of monocular camera

SLR (eye) camera-A single-lens reflex camera has only one lens, which is used for both shooting and framing, so the parallax problem is basically solved. When taking a view, the light emitted by the object is focused by the lens, reflected by the inclined mirror to the focusing screen for imaging, and then reflected by the ridge roof prism (note). Photographers can observe the scene through the eyepiece, and it is the same image as the scene, which is convenient for framing and focusing. When shooting, the mirror will bounce up immediately, the lens aperture will automatically shrink to a predetermined value, and the shutter will open to make the rubber sensitive; After exposure, the shutter is closed and the aperture of the mirror and lens is reset at the same time. Single-lens reflex cameras can be replaced by various wide-angle, medium-focus, telephoto or zoom lenses, and can also be equipped with close-up lenses, telescopic rings or telescopic leather cavities as needed. In short, any scene that can be seen clearly from the viewfinder can be photographed by the camera. A simple single-lens reflex camera using 120 film generally does not need a pentaprism (such as Great Wall DF-4) and can directly focus on the ground glass. Mid-to-high-end single-lens reflex cameras can also be replaced by overlooking viewfinder for framing (such as Zhujiang S-20 1, Nikon F3), so they can also be used for low overhead or inverted framing like dual-lens reflex cameras. This is one of the reasons why the single-lens reflex camera gradually replaces the double-lens reflex camera.

The disadvantages of single-lens reflex camera are as follows: after adding mirror room and pentaprism, the body is thickened and the weight is increased; There will be mechanical vibration and noise when the mirror bounces; The time interval from pressing the shutter button to starting the shutter is also slightly longer than other cameras; It is difficult to focus with a small-caliber lens in a poor light environment because the viewing screen is dark, which is easy to cause focusing errors. Therefore, some foreign journalists picked up cameras with head-up framing and double-image overlapping focusing. They think this camera is small and light, with bright view, quick focus and easy to capture.