len focusing mechanismThe focusing mechanism was used to change the image distance, which was to change the distance between the optical center of the lens and the plane of the film to obtain a clear image. Other than some low-end camera lenses that didn't have a focusing mechanism and couldn't change the image distance, the other lenses, regardless of whether they were fixed-focus or zooming, all had a focusing mechanism. In a microscope, focusing was to adjust the distance between the objective lens and the object to obtain a clear image. The auto-focusing technology was widely used in various optical instruments. From the basic principle, it could be divided into two categories: the active type based on object ranging and the passive type based on image detection.
The active auto-focusing methods mainly included triangulation, infrared ranging, and ultrasonic ranging.
- Triangulation method: Through a special mirror structure, the relationship between the swing angle of the movable mirror and the distance between the object point when the transmission and reflection images overlap is detected by the photoelement on the focusing plane, so as to calculate the distance between the target and the lens to complete the focusing.
- The principle of the infrared ranging method was similar to the triangular measurement method, but the system actively emitted infrared rays as the ranging light source, and the rotation of the infrared light-emitting device replaced the rotation of the movable mirror.
- The ultrasonic ranging method was based on the transmission time between the camera and the object. The instrument was equipped with an ultrasonic transmitting and receiving device, and the integrated circuit determined the focusing distance according to the round-trip time.
Passive autofocus methods mainly included contrast method, split image method, and phase method:
- The contrast method: By detecting the contrast of the edge of the image outline to achieve automatic focusing, two photodetectors were placed at the same distance in front and back of the film position, and the focusing was completed when the output contrast of the two was equal.
- Split-image method: Place a split-image wedge or a micro-prism at the position of the focusing plate. Focus is achieved when the focal point is at the intersection of the split-image wedge or the relevant position of the micro-prism.
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Chen Lin lenChen Linlen was a songwriter and producer. He had participated in the arrangement and production of many songs, including Lyricist: Chen Mei Compositor: Mayday Monster Original Singer: Jiajia Compositor: Chen Linlen Producer: Huang Chengcheng Guitar: Yang Chun Harmonizer: Feng Yini Mix/Master: Pan Junming Cover Design: Mi Yiao Production Company:CZ. Dreams come true Can I cover my eyes so that I won't be sad? Can I take off my mask and be cruel? If I hadn't met you, I wouldn't have believed it, and If I left, what would I get? Is it sad? Is it loneliness? Or is it the next one? It's an excuse that I can't let go? I endure the pain. Love has a beginning and an end. I don't understand holding hands. In addition, he also participated in the arrangement and production of other songs, such as "After I Leave" and "The Queen of Heaven."
All of Len Qingshan's novelsLen Qingshan's novels included The Forgotten Time, Farewell with Flowers, Living With You (originally called So Far So Close), The Next Time Love Comes, My Name, Your Surname, The Lights Are Waning, Time Flies, Our Song of the Thousand Palaces, The First Daughter-in-law of a Noble Family, The Abandoned Wife's Glory, Mountains and Rivers as Songs, The Cold Palace Joy, etc.
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