Do you really understand what a visor is? Don't believe it, take a look


2023-02-15 14:35

  ​The shading ring plays a role in shading, such as the shading ring of the mobile phone lens and the lens shading ring of the camera lens. It is a piece of Mylar sheet that is stamped and formed with SOMA shading material and embedded in the lens. Because it has a shading effect, everyone calls it It is the light-shielding ring and light-shielding gasket.

  The purpose of the shading ring:

  Lens Hood (Lens Hood) is a common photographic accessory installed in front of the camera lens. There are many materials such as metal, hard plastic, and soft rubber. As the name implies, the function of the hood is to block excess light. The camera lens is composed of multiple lenses. When the sun shines into the lens, the light will be continuously reflected between the lens and the lens, resulting in ghost images or the feeling of grayish photos, so the hood can help improve the image quality .

  The blue line is the light path when it is normally phased. The gray line is the surrounding interference light. The light is reflected by the bottom of the rear edge of the lens (red line). At this time, the light reflects forward again with the front edge of the lens, and finally returns to the sensor to produce a halo phenomenon.

  When the light enters the lens body, it is conical, but the shielding of the lens body will block the unwanted light on the four sides and make the image become a rectangle, so the photo we see will be a rectangle instead of a circle. From this we can imagine that the light that enters the lens body and is helpful for imaging should be a rectangular quadrangular pyramid instead of a cone, so the hood is effective to block the excess light, and the photos taken with the hood installed generally have richer colors. And deeper saturation.


  The benefits of using a visor:

  In addition to blocking excess light, the hood has other benefits:

  1. The use of a hood can protect the lens, and the hood can reduce the chance of accidentally touching and damaging the mirror

  2. The lens hood can prevent the lens from being affected by rain and dust

  3. When you accidentally drop the lens to the ground, the hood can help reduce injuries caused by a fall

  When should you not use the visor?

  1. When using the wide-angle lens and built-in flash light at the same time, the hood may block the flash light and form a dark shadow

  2. When using a filter that needs to be rotated (such as CPL), the hood may hinder the use of the filter