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. Read more exciting novels for free
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>
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>
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>
telephoto lens
A telephoto lens was a type of photographic lens that had a longer focal length than a standard lens. It could capture scenes and details from a distance and create unique visual effects. Telephoto lenses were divided into two types: ordinary telephoto lenses and super telephoto lenses. The focal length of an ordinary telephoto lens was close to that of a standard lens, while the focal length of an ultra-telephoto lens was far greater than that of a standard lens. The telephoto lens was suitable for shooting scenery, sports, close-ups, and other topics. It had a unique charm. Some mobile phones were also equipped with telephoto lenses that could zoom in and simplify the background, making it suitable for shooting distant objects and buildings. The use of a telephoto lens required attention to the problem of shaking, which could be solved by using a tripod or a stable support. When choosing a telephoto lens, factors such as focal length, anti-shake function, and optical performance needed to be considered.
photographic lens
zooming lens
The magnifying power of a zoom lens was a concept related to many factors. In a camera lens, there is a maximum magnification, which refers to the lens 'maximum focal length (the focal length of the fixed-focus head is constant) and the closest shooting distance for clear imaging. This value is the maximum value of the lens' magnification. For the continuous zooming lens, the magnifying factor can be changed according to the mechanical positioning structure. For example, there are different magnifying factors such as x0.2-x1.6, x0.3-x2.2, x0.7-x4.5, etc., which can meet different magnifying requirements from small to large. The calculation of the total magnification is related to the objective lens's magnification and the digital magnification. The objective lens 'magnification is related to the large objective lens' magnification and the lens 'magnification. The digital magnification is related to the monitor's size and the size of the diagonal of the CCD-target surface (for example, the diagonal size of the CCD-target surface is 6mm for 1/3 ", 8mm for 1/2 ", and 11mm for 2/3 "). In addition, under different nominal magnifying powers, the lens has a corresponding range of magnifying power and field of view under different fields of view (such as 1/4 ", 1/3", 1/2 "). Professional macro lenses generally had a magnification ratio of no less than 1:1 (1.0x), and small macro lenses also had a magnification ratio of no less than 1:3 (0.33x). <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Olympus lens news
Olympus has a variety of lenses. Here is some information about them: - 12 - 40mm Pro f2.8 lens: released in 2013. At the end of 2021, the second-hand price was around 2500 yuan. It was 80% to 90% new. It had an all-metal body and a solid feel. The zoom ring and focus ring were just right, but it weighed 382g. Its image quality and sharpness performance was good. On the Olympus EM10 third-generation body, the 100% zooming of the auto show photo center in the daytime indoor environment had a better image quality. The sharpness in the outdoor environment was similar to the helmet 14 - 42, 40 - 150, but it had the advantage of a large aperture of f2.8, which could make up for the lack of high sensitivity of the M43 at night and in dim environments. The quality could still be played after 8 years, but the price was a little high. - M.ZUIKO DIGITAL 17mm f/1.8 wide-angle lens (fixed focus): Micro 4/3 mount, priced at 2899 yuan. - M.ZUIKO DIGITAL ED 7 - 14mm f/2.8 Pro wide-angle lens (zoom): has a corresponding mount. - [M. ZDED12 - 50/3.5 - 6.3EZ lens: Although it is a "dog head" lens, it has a wide focal length coverage, with macro and wide-angle lenses. It costs more than 700 yuan second-hand and is cost-effective.] <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The appearance of the lens is white.
The appearance of the lens could be caused by a variety of reasons, such as being contaminated with special substances or the surface coating of the lens being damaged. Here are some possible maintenance methods: 1. Dust cleaning: First, use the lens air to blow away the dust on the surface of the lens. This can prevent the dust particles from scratching the lens during the subsequent cleaning process. 2. Check for stains: If there are stains, do not wipe them with an ordinary cloth. You should first determine the type of stain. If it is oil stains, fingerprints, etc., you can use lens cleaning solution, but you must pay attention to the correct method of use. First, drip the cleaning solution on the lens paper, and then use the lens paper to gently wipe it from the middle of the lens. 3. To avoid improper cleaning: Do not breathe on the lens to clean it, because the exhaled breath contains acidic components, which may damage the lens. Also, do not directly wipe the lens with a lens cloth without cleaning the dust to prevent the dust from damaging the lens surface coating. 4. Daily protection: Pay attention to avoid the lens from coming into contact with substances that may cause whiteness. For example, avoid using the lens in an environment with more chemicals, use the lens cover to protect the lens from dust, water droplets, etc. When storing the camera or lens, choose a dry place to avoid direct sunlight to prevent the lens from getting wet and moldy. If the appearance of the lens is more serious or the above methods cannot be improved, it is recommended to contact a professional lens repair or maintenance personnel for treatment. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The role of the lens changer
The lens changer could change the function and performance of the lens. For example, the Sony-VLVL-UE1 wide-angle lens changer could convert the lens into a wide-angle lens with a focal length of 12mm, and the conversion ratio was 0.75 times. The Sony-VLVL-UE1 fish-eye lens changer could convert the existing wide-angle lens into a fish-eye lens with a wider field of view. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Tenglong lens maintenance
For Tenglong lens maintenance, please refer to the following contents: 1. ** During inspection **: - If you want to disassemble the back cover of the Tamron single-lens reflex camera to check the lens, you need to gently remove the four small screws on the back cover. Pay attention to the possible cable on the cover. Do not break the cable when you open the cover. Then, he removed the three layers of pads under the lid. At this time, the back cover was connected by a circuit board. After removing the screws and wires used to fix the circuit board, the back cover could be removed to see the lens. 2. ** When cleaning the lens **: - Observe whether there is dust or mold inside the lens. If there is, use cotton cloth or good quality napkins to clean it. If possible, it is best to use a cleaning tool for the lens, and pay attention to avoid scratching the lens during the cleaning process. - When the connection between the camera and the lens failed, first check if the connection was accurate and if there were any obstacles. If there were no problems, you could use a cotton cloth to clean the contact points of the lens, because it might be a problem caused by mold. 3. ** When the lens is damaged **: - If the motor in the lens was damaged, they could go to the shop to get a motor of the same model and replace it. If the lens itself was damaged, the price might be more expensive. It could be matched with a lens of the same model in a professional shop, and then the damaged lens could be removed and replaced with a new lens. However, if the lens was damaged, it was best to repair it at a professional repair shop. 4. ** When the compact flash card fails **: - If he found that the compact flash card was faulty, he could remove the card and then re-install it. If that didn't work, he could only format the compact flash card. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>