How to explain the phenomenon of starlight?

"Starlight effect" is a special phenomenon of light diffraction, which is generally caused by the narrow aperture of the lens. Generally speaking, from the perspective of photography, we usually try to avoid light diffraction. But from another perspective, if you want to shoot the "star-awn effect" without using the star-awn filter, there are several necessary factors: A. Narrowing the aperture. B. In the scene, there is a strong point light source. C. after the point light source is injected into the lens, diffraction occurs. The shape of the star screen effect is related to the blade design of the aperture. In consumer-grade DC, Olympus cameras can often form a beautiful hexagonal starry sky. However, some cameras can only form a circular halo star awn based on the blade design. In this example, we use Olympus digital camera to shoot. 1. Use aperture priority mode to minimize aperture, which is about F8-F 1 1 for consumer digital cameras. 2. Look for scenes with a little light source, such as A. Street lamps in the night scene. B. water wave reflection in backlight. Strong light being welded. 3. Try to use a camera with a long focal length (that is, a camera with a large optical zoom ratio), and the phenomenon of diffraction may be more obvious. In addition, the silhouette technique is also used in this picture, that is, in the backlight environment, the aperture is narrowed and a faster shutter is used to make the subject form an almost all-black outline. The point light source refracts from the water surface, passes through a camera with a narrow aperture, and forms the diffraction phenomenon of this picture with a higher focal length.

Change the color of water waves. When shooting night scenes, how to make the lighting achieve the effect of "stars gathering"! 1, the minimum aperture must be used (note: the larger the value, the smaller the aperture, otherwise the smaller the value, the larger the aperture) 2. The camera must be fixed with a tripod (note; Shooting at night often takes several seconds, even tens of seconds, which is impossible by hand. 3. Reduce the ISO setting to avoid noise (note: set a lower ISO in the camera parameters, such as ISO64 or ISO 100). 4. It's best to use the timed form (note: when you press the shutter by hand, the camera will inevitably shake slightly at that moment. If you use timed shooting, take more photos according to the above requirements, and the lighting will definitely achieve the effect of "stars gathering". (Note: The above method is also applicable to fireworks. )