The direction of motion inside the lens
The direction of movement inside the lens mainly included vertical, horizontal, and vertical directions. There were two types of movement in the vertical direction: pushing the camera (pushing the subject from far to near) and pulling the camera (gradually moving away from the subject); horizontal movement included shaking the camera (the camera was placed in a fixed position and panned left and right or up and down), moving the camera (the camera moved in all directions along the horizontal plane); vertical movement included lifting the camera (the rising lens slowly rose from the flat shot to form a bird's eye view shot, and the descending lens was the opposite). In addition, there were revolving lenses that moved in a circular motion around the main body, as well as following lenses (the camera followed the subject of the motion, and the lens was divided into two directions: leading in front of the main body and following behind the main body). Different directions of motion had different effects, such as protruding the main body, increasing emotional appeal, and showing a sense of space. Read more exciting novels for free
The direction of the laparoscope lens
In a laparoscopy, in order to achieve better exposure of the surgical field, the camera angle could be adjusted in many ways. For example, adjust the direction of the lens by grasping the eight-word key words of "bubble, rub, flat, center, advance, retreat, rotate, and follow"."flat" meant to make the base of the laparoscope flat so that the field of view was in line with the habits of laparotomy.(Generally, the lower edge of the liver and the spleen are used as horizontal references.)"Advance" can make the target area more clear but the field of view is smaller."Retreat" can make the field of view larger but the clarity of the target area is reduced.(It is generally used to understand the relationship between the surgical field and the surrounding structures),"Rotation"(30-degree rotation of the laparoscope) can observe the target tissue structure from different sides, and "Following" can follow the thoughts of the chief surgeon. Through the operations of advancing, retreating, rotating, and following, the viewing angle and direction of the laparoscope can be adjusted in real time according to the surgical needs to ensure clear exposure of the surgical field. In addition, the adjustment of the direction of the lens was indirectly affected by changing the method of hole arrangement (following the principle of isosceles-triangle with the focus as the apex, or the principle of establishing observation holes and operating holes in a fan-shaped shape with the focus as the center), adjusting the angle between the left and right operating rods (more than 60 degrees was conducive to the operation and did not affect the exposure of the laparoscope), so as to achieve the ideal surgical field exposure effect. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Professor-level problem: the contradiction between the direction of sunrise and sunset in the equator and the apparent motion chart!
The contradiction between the direction of sunrise and sunset in the equator and the apparent motion map can be solved by the following explanation: At the equator, the Earth's axis of rotation intersected with the sun's trajectory at a point, which meant that the longitude of the equator was 0 degrees. So when the sun rises in the east, it actually rises on the left side of the earth's axis of rotation, and when the sun sets in the west, it actually sets on the right side of the earth's axis of rotation. However, the sun actually rises from the east along an equator and sets from the west along an equator. Therefore, the position of sunrise and sunset in the equator is actually opposite to the direction of the motion map. This contradiction could be solved by combining the trajectory of the sun with the trajectory of the earth. As the Earth rotated, the Sun also revolved around the Earth in a spiral. Therefore, when the sun rises from the east, its trajectory on the equator is actually moving from left to right, and when the sun sets in the west, its trajectory on the equator is actually moving from right to left. Therefore, the position of sunrise and sunset in the equator is the same as the direction of the motion chart.
Canon lens, Nikon lens
Canon lenses and Nikon lenses were well-known brands in the field of camera lenses. In terms of Nikon lenses, the new Z-mount lenses were generally of high quality, such as holo-field compatibility and excellent corner resolution. The F-mount was limited by the caliber and the distance between the two sides, while the Z-mount had a great improvement in this aspect, especially in the wide-angle to mid-focal length section. Canon lenses, such as the RF28 - 70mm F2.8 lens, had a constant large aperture of F2.8. It was portable, and the image quality was average, even a little beyond the positioning of the silver ring lens. It also had anti-shake function. However, its price was sometimes affected by marketing routines. For example, during the 11/11 period, the price of Canon RF28 - 70mm was higher than the recommended price on the official website and did not return to normal value. These two lenses had their own optical design features, advantages, and market positioning under different camera mount systems. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What is the lens of the camera lens?
Based on context alone The lens of the camera lens was made up of many different types of lenses. This included a concave lens, which had a thick middle and thin edge structure. It had a converging effect on light, which helped to focus the light on the imaging plane, making the image clear. There were also concave lenses, which were thin in the middle and thick at the edges. They had a diffusing effect on light and were often used to correct aberrations. In addition, there were also aspheric lenses. These lenses were not the traditional spherical shape. They could better correct aberrations, improve image quality, and reduce image distortion and blurring. They were widely used in modern camera lenses. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Canon lens and Nikon lens interface differences
Canon lenses mainly had the lens mount, which was Canon's full-frame single-lens reflex camera mount, as well as the lens mount, such as the ESF-S mount, the ESF-M mount, and the lens mount. Nikon lenses mainly had the lens mount, such as the F-mount, and the Z-mount. Their bayonet types were different, and their size, the distance between the two sides, the number and location of electronic contacts, and other parameters were also different. These differences determined the compatibility between the lens and the body, as well as the realization of functions. For example, Canon's RF-mount and Nikon's Z-mount were large-caliber mounts, but there were still differences in specific size and other characteristics. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Image quality of a single-lens reflex telephoto lens
Different single-lens reflex telephoto lenses had their own characteristics. For example, 85mm f1.2 was easy to run out of focus when the aperture was fully open and the purple edge was a little serious, but it could present beautiful pictures when shooting portraits or still lives;70 - 200mm f2.8 was one of Canon's big three yuan, with a wide focal range and no obvious shortcomings in image quality;100 - 400mm f4, in addition to being heavy and not having a large aperture, had sharp image quality; 50mm f1.8 "small spittoon" had average image quality, but it was cheap; The 24 - 70mm f2.8 Canon lens was more versatile, but the aperture was not large enough. The RF100 - 400mm F5.6 - 8IS USM lens was light and sharp. The Canon EF50mm F1.8II had a F1.8 large aperture circle focal lens, which made the background blurred and beautiful. The Canon EF40mm F2.8ATM had advantages in workmanship, overall quality, and performance, and the picture quality was excellent. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Does a single-lens single-camera have a lens?
" Standalone " usually meant that it only had the camera body and did not include the lens. Therefore, a single DSLR camera did not have a lens. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to stack the lens of a single-lens reflex camera
The full name of the DSLR was " single-lens reflex viewfinder camera." It only had one mount. In theory, it could only be connected to one lens for optical imaging. Under normal circumstances, the lens could not be stacked. However, there were special uses, such as reversing the lens or connecting the zoom lens. However, these still needed to rely on a pure optical lens to use. On the basis of this lens, you could stack the transfer ring, zoom lens, etc. to achieve different effects. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Nikon old-fashioned single-lens reflex lens
Nikon's old-fashioned DSLR lens had many features. In terms of optical quality, some of the old lenses of Nikon DSLR had extremely high optical quality, such as the Nikon Nikkor 105mm f/2.5. Its design had been verified for a long time, and the lenses were polished and assembled carefully. Some of the materials used were more expensive than modern lenses, and special glasses such as thorium glass and lead glass, which were now no longer used, were used. This helped to provide a higher index of refraction, improve color difference control, and overall image quality. In terms of sharpness and color performance, it was not bad by today's standards. In terms of mechanical technology, the metal lens barrel and smooth focus ring of the old Nikon DSLR lens were different from the modern automatic lens made of plastic. It was more mechanical, and its texture, weight, and feel could give the photographer a retro film era feeling. In terms of adaptability, the old-fashioned lens of Nikon's DSLR could be perfectly combined with some current cameras, such as the Sony A7 series, the Fuji X-T series, and the Canon Eos R series. The electronic viewfinder of the mirrorless camera could enlarge the real-time view, making it easier to manually focus. Combined with the focus assist function, it greatly improved the experience of using it on digital cameras. However, for beginners, it was not recommended to use the old Nikon DSLR lens because the old lens had problems such as focusing stagnation and hesitation, although the accuracy was acceptable. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Is the bright moon lens MK9 a super bright lens?
The MK9 of Mingyue lenses was the anti-counterfeit mark of the 1.71 index lens, and the 1.71 index lens belonged to the Mengmeng super bright series of Mingyue lenses. This series had a light transmission of up to 98.6%, and the characteristics of clear and bright vision. Therefore, the Bright Moon lenses marked as MK9 were super bright lenses.