Why is there a dark aperture around the street lamp when shooting at night?

When shooting night scenes, a circle of dark apertures around street lamps is caused by halo effect in optical phenomena. Halo effect means that when light passes through a lens or an optical system, due to the diffraction, scattering and reflection of light, some light will spread and interfere, thus forming a halo.

Halo effect is related to the propagation and diffraction of light. When light passes through a lens or an optical system, diffraction occurs, that is, when light passes through an optical system, it bends and propagates. This diffraction phenomenon will change the propagation direction of light and make the light form a fuzzy halo on the imaging plane.

Street lamp is one of the light sources in night scene shooting, which will emit strong light. When the light passes through the camera lens, it will be diffracted, making the light form a halo on the imaging plane. Because the light around the street lamp is concentrated, the halo effect in this area is obvious, forming a circle of dark aperture.

Halo effect is also related to the quality of optical system. If the quality of the camera lens is poor, more diffraction and scattering will occur when the light passes through the lens, thus increasing the degree of halo effect. On the contrary, if the quality of the camera lens is good, the diffraction and scattering of light will be reduced, and the halo effect will be weakened accordingly.

In order to reduce the halo effect, the following measures can be taken:

1. Use a high-quality camera lens: A high-quality lens can reduce the diffraction and scattering of light, thus reducing the halo effect.

2. Use a lens with a smaller aperture: a smaller aperture can limit the propagation range of light and reduce the degree of halo effect.

3. Use filters: Appropriate use of filters can reduce the scattering and reflection of light, thus reducing the halo effect.

4. Adjust the shooting angle: Changing the shooting angle can change the propagation path of light and reduce the degree of halo effect.

In a word, the dark aperture around the street lamp when shooting at night is caused by halo effect. Halo effect is the phenomenon of diffraction and scattering when light passes through a lens or optical system, which makes the light form a fuzzy halo on the imaging plane. In order to reduce the halo effect, some measures can be taken, such as using high-quality camera lens and adjusting shooting angle.