Differences between matte box and hood

There is a hood to reduce radiation, but without a hood, direct light exposure will cause high radiation.

Lens hood is a device installed on the front of photography lens, digital camera and video camera to block harmful light. It is also one of the most commonly used photography accessories. Lens hoods are made of metal, hard plastic, soft rubber and other materials.

Most 135 lenses come standard with lens hoods, and some lenses need to be purchased separately. The lens hood models used for different lenses are different and cannot be used interchangeably.

Composition

Strictly speaking, the lens hood is an integral part of the lens optical system. A lens is composed of several or dozens of lenses. Each lens has two reflective surfaces, and a lens has dozens of reflective surfaces. The more reflective surfaces there are, the greater the impact on the lens' imaging. Especially when shooting with backlight or side backlight.

Multiple reflective surfaces will interfere with each other to form a halo. Halos can cause colors to appear dull (desaturated colors) or appear flared. Sometimes the picture taken looks like it is covered with a layer of mist. In fact, this is caused by not using a lens hood, and is not a problem with the quality of the lens. The inner wall of a high-quality lens hood has undergone multiple matting treatments.

The reflectivity of its inner wall is only about 10%, and it will not refract the lens when used. The use of a lens hood can play a good role in suppressing screen halos, preventing stray light from entering the lens, blocking rain and snow splashes, protecting the camera and lens from accidental collisions, and giving full play to the potential optical qualities of the lens.