Professional cameras are also called SLR cameras, and the complete ones should be called single-lens reflex cameras. The unique design of the mirror and prism of this kind of camera enables the photographer to directly observe the image passing through the lens from the viewfinder.

After the light reaches the reflector through the lens of the camera, it refracts to the focusing screen above and forms an image. Through the eyepiece and pentaprism, the photographer can see the scenery outside in the viewing window.

When shooting, when the shutter button is pressed, the reflector will bounce up, and the shutter curtain in front will be opened at the same time. The light (image) passing through the lens will be projected on the photosensitive part (traditional camera is film, digital camera is CCD or CMOS) to make it sensitive, and then the reflector will immediately return to its original state, and the image can be seen again in the viewing window.

The lens of a professional camera can be completely removed and replaced with another lens, thus obtaining different shooting effects. There are many kinds of lenses for professional cameras, and the price ranges from thousands to tens of thousands, and many lenses are even more expensive than the fuselage.

All kinds of functions and indexes of the fuselage must rely on excellent optical lenses to complete. Through the image conversion of the lens group in the lens, the best effect of the current lens is achieved. How to choose a variety of camera lenses.

It depends on the kind and route of shooting you are good at, to judge what lens you should buy most. Don't buy it blindly, resulting in repeated focal lengths.