Full-frame fish-eye lens
A full-frame fisheye lens was a type of fisheye lens. The fisheye lens was a type of ultra-wide-angle lens with a focal length of about 6 - 16mm and an angle of view close to or equal to 180°. Its front lens was shaped like a parabola and protruded toward the front of the lens. The functions of the full-frame fisheye lens included: 1. ** Photographic Creation **: Can create artistic photos with a large field of view and large distortion. It can display unique visual effects and shoot images with extremely wide angles of view. The effect of the images is beyond the regular and fixed forms that people see in their daily lives. 2. ** Industrial field **: In some industrial scenes that require wide-angle imaging, such as the monitoring field, it can cover a large monitoring range. 3. ** Scientific research **: It can be applied to the study of cloud formation in Meteorology. It can also be used in aerospace cameras to help obtain wide-angle image information. 4. ** Medical field **: Able to provide wide-angle imaging in specific medical imaging scenarios. 5. ** In terms of imaging, a full-frame fisheye lens can meet the requirements for scenes that require large viewing angles, such as dome imaging. Read more exciting novels for free
Fish-eye lens is
A fisheye lens was a lens with a focal length of about 6 - 16mm and a viewing angle close to or equal to 180°. It was a type of ultra-wide-angle lens. Its front lens was shaped like a parabola and protruded to the front of the lens, which was similar to the eyes of a fish, hence its name. The concept was proposed and developed in 1906. In the 1920s, it was used for the study of cloud formation in meteorology. Robin Hill was the first person to truly create a fisheye lens and use it for commercial use. Mass production began in the 1960s. It was usually composed of a front group of imaging lenses and a rear group of correction lenses. It was divided into half-frame fisheye lenses and full-frame fisheye lenses. It was first used in photography to create artistic photos with a large field of view and large distortion. It was also widely used in fields that required wide-angle imaging, such as surveillance, dome imaging, aerospace cameras, and other industrial, medical, and scientific research fields. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Half-frame with full-frame lens, okay?
It was feasible to install a full-frame lens on a half-frame body, but there were some problems. From the perspective of angle, due to the small size of the sensor on the half-frame body, the actual shooting angle would be narrower, about 1.5 times or 1.6 times, which had a significant impact on wide-angle shooting. For example, the 50mm full-frame lens on the APS-C camera was equivalent to the 75mm or 80mm lens, which would weaken the wide-angle effect, which was not conducive to large-scale scenery and architectural shooting. In terms of depth of field effect, although the focal length of the lens was longer due to the equivalent focal length, it would not obtain an additional shallow depth of field effect. It might be difficult to achieve soft background blurring in portrait photography. For high sensitivity performance, this mainly depended on the camera's sensor rather than the lens, so a full-frame lens would not improve the high Iso performance of a half-frame camera. The full-frame lens was designed for a full-frame body. When used in a half-frame camera, the edge of the lens would not be used, resulting in the potential of the lens not being fully utilized, and the performance of the lens would be reduced. In terms of image quality, it mainly affected the image quality at the edge of the lens (the center image quality was usually not affected, especially after the aperture was reduced. This effect was not significant on high-quality lenses), and the number of final image resolution would be reduced after APS-C mode was turned on. Full-frame lenses were usually larger, heavier, and more expensive than half-frame lenses. Mounted on a half-frame body would offset the advantages of a half-frame camera being light and portable, and it would also put pressure on people with limited budget. In addition, the autofocus performance of the full-frame lens was worse on the half-frame body. Different brands and models of lenses and bodies might have problems such as slow focusing speed and reduced accuracy, which would affect the shooting efficiency. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Is the Canon 2470 full frame lens?
Canon's EF24 - 70mm f/2.8L USM first-generation lens was a 135mm full-frame lens. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Full-frame lens selection
There were many factors to consider when choosing a 70 - 200 full-frame lens. From the brand and model point of view, Canon had the EF70 - 200mm lens series, including F2.8LIS USM, F2.8LIS II USM, F2.8LIS USM, F4LIS USM and many other models. Different models had differences in aperture, anti-shake, image quality, etc. For example, a larger aperture lens might have an advantage in low-light environments and blurring effects. The LUMIX S Pro 70 - 200mm F2.8 O.I.S. lens from Matsushita was aimed at the professional market. It had a large aperture of 2.8 for creative production. The lens was equipped with a tripod ring, and its button design made it easy for the user to adjust the anti-shake adjustment, focus adjustment, and other personal settings. It was similar in appearance to the F4 lens of the same series, and the workmanship was solid. It supported splash resistance and could be used in low temperature environments of-10 ° C. Its optical image stabilization could be selected in different gears, and the shortcut button could be customized. The lens had an aperture of 82mm, which guaranteed light transmission and high image quality. The number of 11 aperture blades made the blurring performance excellent, and the double floating focus design was used to suppress the breathing effect. In the image quality test, the center image quality was sharper under different focal lengths, and the edge image quality also had its own characteristics in each focal length. Sima had an APO 70 - 200mm f/2.8 EXDG OS HSM full-frame large-aperture telephoto lens with optical image stabilization and an APO zoom lens. In addition, he also had to consider the use of the lens. If it was mainly used for portrait photography, the 70 - 200mm lens was a good choice for portrait lenses. It could zoom in on people from a distance, and the 200-point camera was suitable for close-ups. However, compared to 85mm, 135mm and other classic portrait fixed-focus lenses, there was a certain gap in image quality and blurring out of focus. However, special out of focus effects could also be achieved by sticking coins on the UV-lens. In terms of landscape photography, the 70-end could cope with most telephoto shooting needs, making it easier to compose than wide-angle; the 200-end could bring the vision into the distance, recording distant details and light and shadow, and the telephoto lens could make the picture feel compressed, exaggerating the distance and compressing the depth of field. The size, weight, and price of the lens could not be ignored. For example, Canon's EF70 - 200F4IS lens was well-coordinated with the body, making it unobstructed for long-term holding and walking. The original suggested retail price was raised from $1,299 to $1,499 (for reference only, the price would fluctuate according to different sales channels and time), and some models would be stopped in March 2021, which would also affect the purchase choice. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Is the Nikon dx lens full frame or half frame?
The Nikon DK lens was not a full-frame lens, but a lens suitable for APS-C frame (half-frame) cameras. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Distortion correction of fish-eye lens
Fish-eye lens distortion correction aims to reduce or eliminate the image distortion effect caused by fish-eye lenses. When correcting the distortion of the fisheye lens, the core was to solve a "good" remap matrix, which rearranged some of the original image's pixel-points (or intervening points) and "pieced" them into a rectangular image."Good" was linked to the final requirement, and different tasks often used different correction/distortion solutions. For example, in the smart security industry, whether it was a monocular camera or a monocular camera, the images captured would have distortions, which was the same as the distortion correction principle of a fisheye camera. For monocular cameras, in order to obtain the corresponding relationship between the camera's coordinate system and the three-dimensional world coordinate system, the barrel distortion and pillow distortion of the camera needed to be corrected. For binocular cameras, in order to do epipolar line alignment and realize depth estimation, the output of the two cameras needed to be transformed into the same coordinate system. Teacher Zhang Zhengyou's chessboard correction method estimated the internal and external parameters and distortion coefficient of the camera through the position coordinates of the marker, and then calculated the remap matrix. This method had a good correction effect for monocular and binocular cameras. In terms of practical operations, fisheye correction can also be performed using python language (only relying on the opencv-python package and numpy package), and fisheye distortion correction can also be performed from code examples such as PILimport Image. In addition, the distortion correction function based on digital image processing was also applied to the fisheye lens correction. This solution required rearranging the arrangement of the elements, but for the ultra-wide system where the edge image quality itself was a big problem, it might lead to the image quality of the most edge area being worse. Some equipment would use the image field redundant design and the sensor to perform the redundant matching of the elements to reduce the side effects of the digital correction. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Fish-eye lens imaging theory
The imaging theory of the fisheye lens was based on its special optical structure design. The fisheye lens had a large spherical curvature, similar to the spherical crystal of a fisheye, and the imaging plane was closer to the lens. The visual effect was similar to a fish observing things on the surface of the water. When the fish was close to the surface of the water, the angle of view could reach a wide angle of nearly 180°. This phenomenon was based on the principle of total reflection and optical reversibility. In terms of structure, the front lens of the fish-eye lens protruded from the front in a parabolic shape in order to maximize the camera angle. It was generally believed that lenses with a focal length of 16mm or shorter were fisheye lenses. However, in engineering, lenses with a viewing angle of more than 140 degrees were collectively referred to as fisheye lenses. In fact, there were also lenses with a viewing angle of more than 270 degrees. In terms of imaging mode, the M12 fisheye lens (180°) generally used vertical or horizontal in-cut imaging mode (mode 1 Circular Fisheye, mode 3 Full Horizontal). At the same time, fisheye lens imaging relied on artificially introducing a large number of barrel distortions to obtain a large field of view, so that it could obtain image information with a large field of view. However, except for the shape of the object in the center of the image, the other parts that should be straight lines had a certain degree of distortion. When matching an image sensor with a fisheye lens, a 1:1 or 4:3 image sensor was generally selected to maximize the use of effective pixelation. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Fish-eye lens for piano teaching
Using a fish-eye lens in piano teaching has certain advantages. The fish-eye lens had a large angle of view and could accommodate more scenes. It could adapt to the needs of shooting in a small space. In a piano teaching scene, such as an online piano lesson, the fish-eye lens could be used to let students see more details of the teaching environment, such as the teacher's overall performance posture, the piano's overall appearance, and so on. However, there were some problems with using a fisheye lens. Due to the distortion of the image, the straight lines around the screen would be bent. When shooting piano teaching content, if you need to show some flat music score or the straight arrangement of the keys, there may be distortion. Therefore, when using it, one had to pay attention to the selection of the shooting angle and content. For example, the subject that needed to be highlighted (such as the teacher's hand movements, etc.) could be placed in the center of the lens because the straight line in the center of the lens could maintain its original state. This was also the brightest and clearest part of the photo to reduce the impact of distortion on the teaching content. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Can a full-frame camera be equipped with a non-full-frame lens?
Canon's full-frame single-lens reflex camera could not be equipped with a non-full-frame lens because the mount of the full-frame single-lens reflex camera was the EF-mount, while the mount of the non-full-frame lens was the EF-S. The two mounts were different. In Nikon's single-lens reflex cameras, although both full-frame and non-full-frame single-lens reflex cameras used the F-mount, due to the difference in imaging, a full-frame single-lens reflex camera with a non-full-frame lens would cause a loss of half of the resolution. The picture would be cropped and there would be serious dark corners and black edges around it. It was not recommended to match it like this. For photo shooting, it is not recommended to match a full-frame camera with a non-full-frame lens. For video recording, you can choose to match a non-full-frame lens according to the characteristics of the camera and the recording format. However, Canon's original APS-C single-frame single-lens reflex lens (that is, the ESF-S lens) cannot be used directly. The full-frame micro-single lens can be fixed in 1.6x mode when using the ESF-S lens through the transfer ring. There are some functional restrictions. In general, there were many problems with a full-frame camera with a non-full-frame lens. It was not recommended to match it like this. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Sony full-frame 50mmf1.8 lens
The full-frame 50mm f/1.8 lens was a fixed-focus lens, which belonged to the 135mm full-frame micro-single lens. The lens mount was the PE mount, and the filter size was 49mm. In terms of optical parameters, the maximum aperture was F1.8, the minimum aperture was F22, the number of aperture blades was 7, the focal length was fixed at 50mm, the closest focusing distance was 0.45m, the maximum magnification was 0.15 times, and there was no anti-shake performance. The structure of the lens was composed of five sets of six lenses, including one aspheric lens. The lens used a metal bayonet, which was sturdy and durable. The focusing ring was wide and the vibration was moderate. It felt comfortable. In terms of price, the official yen price was 38,000 yen, which was about 2500 yuan, and the price was about 1632 yuan. When it came to e-commerce promotions, the price could be even lower. The cost-performance advantage was obvious. In terms of imaging performance, the center sharpness was around 96%, the center resolution was around 78%, and the edge resolution dropped significantly. A large aperture could bring about a better blurring effect. It could be used to highlight the main body in portraits and scenery shooting. It also had an advantage in night shooting because it could obtain sufficient light. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>