What does the camera lens focal length mean?
The focal length was the division of the focal length of the lens. In video cameras, film, digital cameras, movie cameras, and other equipment, there were focal lengths that were divided according to their own frame. For the convenience of memory and understanding, the focal length of the lens was often converted to the focal length of the 35mm camera (135mm camera) lens. The focal length was divided as follows: the focal length was below 20mm for the ultra-wide-angle lens; 21mm-40mm for the wide-angle lens; 41mm-60mm for the standard lens; 61mm-100mm for the medium-focal lens; 101mm-180mm for the medium-telephoto lens; 180mm-300mm for the telephoto lens; 301mm and above for the ultra-long-focal lens. Read more exciting novels for free
the focal length of a camera lens
The focal length was the division of the focal length of the lens. It was generally divided into super wide angle, wide angle, standard, medium focal length, medium telephoto, telephoto, and super telephoto. Take a 35mm camera (135 camera) as an example: a lens with a focal length below 20mm is an ultra-wide-angle lens; a lens with a focal length of 21mm-40mm is a wide-angle lens; a lens with a focal length of 41mm-60mm is a standard lens; a lens with a focal length of 61mm-100mm is a medium-focal lens; a lens with a focal length of 101mm-180mm is a medium-long focal lens; a lens with a focal length of 180mm-300mm is a telephoto lens; A lens with a focal length of 301mm or above was a super telephoto lens. Different focal lengths had different characteristics and applicable scenes. For example, the ultra-wide angle lens had a wide angle of view, which was suitable for shooting large scenes such as scenery and architecture; the standard lens was close to the human eye's angle of view, with very little distortion, which was more suitable for documentary photography; the telephoto lens could achieve background blurring, compress space, and highlight the main body, but the scene was small, so it was difficult to blend the background with the main body well. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to exercise the focal length of the camera lens
You can practice using various focal lengths to understand the characteristics of each focal length of the lens, understand the angle and perspective relationship, and make use of the different depth of field of each focal length. For example, using a telescope (A lens with a focal length of more than 200mm) When shooting, you can feel that it has little sense of distance and has a compression effect.(85mm-135mm focal length lens) The perspective closest to the human eye, can accurately reflect the shape of the subject, can be used for portrait photography; Wide-angle lens (focal length below 35mm lens) can emphasize the sense of distance; Standard lens (focal length around 50mm lens) The shooting effect is extremely natural, without exaggeration. During the shooting process, he constantly summarized the differences in the effects of the images shot by different focal length lenses, which helped to train the focal length of the camera lens. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to increase the focal length of the camera lens
To increase the focal length of the camera lens, the following methods can be used: 1. Use a telephoto lens: The focal length of a telephoto lens is larger. For example, a 50mm lens is considered a standard lens, and a 200mm lens is a telephoto lens. Using a telephoto lens can zoom in on distant objects and make the picture more full. This is the most direct way to expand the focal length. 2. Use a magnifying lens: The magnifying lens can be directly installed on the lens to double or more the focal length. For example, the focal length of the camera lens was 50mm. After installing a 100mm magnifying lens, the focal length of the camera could be expanded to 100mm, and the cost of this method was relatively low. 3. Use digital zoom: Most modern digital cameras are equipped with digital zoom, which uses software algorithms to magnify images without changing the focal length of the lens. However, this method will cause the quality of the image to deteriorate because it is achieved by cropped images. It is not recommended to use it often. 4. Use post-production software: If you don't have a large focal length lens or a magnifying lens, you can use post-production software (such as PowerPoint or Lighthouse) to simulate a large focal length effect by trimming and adjusting the image. However, this requires a certain amount of skill and experience, and is often used in creative photography. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to calculate the focal length of a camera lens
The focal length of the lens was calculated based on the size of the field of view, the distance from the lens to the object being captured, and the size of the image. The specific calculations were as follows: 1. ** Calculating the relationship between the focal length of the lens and the field of view, object distance, and image size ** - When the width of the image (the width of the image of the object on the CCTV target), the width of the object, and the distance from the object to the lens are known, the focal length of the lens is (f = wL/W); - When the height of the image (the height of the object on the LCD target), the height of the object, and the distance from the object to the lens are known, the focal length of the lens is (f = hL/H). 2. ** Field of view calculation ** - If you know the horizontal field of view, or the vertical field of view, you can calculate the width of the scene according to the formula. - Horizontal field of view <<beta>= 2tg^{-1}<frac{w}{2f}>>, vertical field of view <<q>= 2tg^{-1}<frac{h}{2f}>>(Here,<w>>,<h>>,<f>> are image width, image height, and lens focal length respectively). In addition, the concept of equivalent focal length (equivalent focal length = focal length x equivalent coefficient) was also involved when matching lenses with different frame cameras, which helped to compare the imaging effects of lenses between different frames. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Calculating the focal length of a single-lens reflex camera
In a single-lens reflex camera, the focal length had the following important functions: 1. ** Image size **: The length of the focal length of the lens determines the size of the image of the object on the imaging medium (such as film or CCDs). When shooting the same subject from the same distance, the image formed by the long focal length of the lens was large, and the image formed by the short focal length of the lens was small. 2. ** Field of view **: The change of focal length has a direct impact on the shooting angle. When the focal length is smaller, the shooting angle is larger, and the shot image can accommodate more picture elements. A small focal length lens can be called a wide-angle lens; when the focal length is larger, the shooting angle is smaller, and the subject can be zoomed in and out. A large focal length lens is called a telephoto lens. For example, when shooting scenes that need to accommodate more picture elements, you can choose the wide-angle lens or the wide-angle end of the zoom lens; when shooting portraits, flowers, wild animals, etc., you can use the telephoto end to effectively capture the scene composition. 3. ** Depth of field **: Focus is one of the three elements of depth of field. The smaller the focal length, the clearer the background and the greater the depth of field. Therefore, the wide-angle end was often used to shoot scenes that required a clear background, while the telephoto end was used to shoot close-up images of portraits and animals to simplify the background and highlight the main body. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to adjust the focal length of the Canon camera lens
Different types of Canon cameras had different ways of adjusting the focal length of the lens: - ** Card camera or telephoto camera **: You can press the buttons marked with W and T on it, or it may be a ring with a small handle on the shutter button that can be twisted and marked with W and T nearby to adjust the focal length. - ** DSLR or single-camera **: Turn the zoom ring on the lens to adjust the focal length of the lens. - ** Some Canon cameras **: After focusing in the AF-mode, adjust the lens focus mode to the MTF-mode to lock the focus and re-compose the picture; you can also set the camera to the live-view mode.(Liquid crystal display viewfinder mode), directly click on the touch screen to select the focus; or turn the AFF/MV switch on the lens to MV, and turn the focus ring on the lens to manually focus; or in the autofocus mode, you can use the four-point cross star on the upper right edge of the back of the camera, press the dial wheel behind the shutter to change and select the focus. In addition, on the back of some models (such as the 70D), there was a magnifying button (the icon was in the shape of a magnifying glass). Pressing it could magnify the image by a certain number of times. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What kind of camera is the 85 focal length lens suitable for
The 85mm focal length lens was suitable for shooting portraits, and there were excellent models that were suitable for many camera brands. For example, the Nikon Z85F1.2 camera had a suitable lens. Canon cameras also had lenses like the RF85mmF1.2LUSM, which used nine sets of 13 optical structures, including one piece of KD ultra-low dispersion lens, one piece of polished aspheric lens, and one piece of PR optical element. It had nine circular aperture blades, the closest focusing distance was 0.85 meters, and the maximum magnification was about 0.12 times. It used a ring-shaped ultrasonic focusing drive system. The filter aperture was 82mm, the maximum diameter and length were about 103.2×117.3 mm, and the lens weighed 1195 grams. It was priced at 17899 yuan. The F1.2's maximum aperture could bring about a relatively small depth of field and a large and beautiful blurring effect. It could highlight people very well in portrait photography. The camera also had an 85mm f/1.4 DG HSM Art lens, which was a medium-telephoto fixed-focus lens with built-in anti-shake functions. The 85mmF1.8 lens in Pantheon's full-frame fixed-focus F1.8 series used eight sets of nine lenses (two ED lenses) to provide a soft blurring effect. Although the Fuji camera did not have a direct 85mm focal length lens, the XF56mm F1.2RQR lens had a focal length of 85mm in the 35mm format, which could be used for portrait shooting and other purposes. The 85mm focal length lens of different camera brands could play the advantages of being suitable for shooting portraits and other scenes on their respective camera bodies. The specific choice depended on the photographer's comprehensive consideration of the camera brand, performance, budget, and many other aspects. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to adjust the focal length of an old-fashioned camera lens
For old-fashioned cameras equipped with a zoom lens, the focal length could be changed by turning the zoom ring to achieve the optical zooming effect. The lens was usually marked with a focal length value, and the position of the focal length scale could be used to determine which focal length was used. If a fixed-focus lens was installed on the camera, the focal length adjustment could only be achieved by changing the lens with a different focal length. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How does the focal length of the camera lens calculate the distance?
1. First, it was the calculation of the focal length of the lens, the size of the field of view, and the distance between the lens and the object being captured: - There are formulas,[f = wL/W] and [f = hL/h]([f] is the focal length of the lens;[w] is the width of the image, which is the width of the image of the object on the target surface of the camera;[W] is the width of the object;[L] is the distance from the object to the lens;[h] is the height of the image, which is the height of the object on the target surface of the camera;[H] is the height of the object.) - The installation distance or the field of view can also be calculated according to the angle of view, the distance between the camera and the object, or the width of the object to be seen, with the formula, Tan(alpha/2)=0.5×V/D. 2. In addition, if you know the horizontal or vertical field of view, you can calculate the width and height of the scene according to the formula.(\beta = 2tg^{-1}\)(Part of the formula content is omitted here, related to <w>,<H>,<F>), vertical field of view <(q = 2tg^{-1})(also omitting part of the formula content, related to <w>,<H>,<F>). There is a certain relationship between the horizontal field of view and the vertical field of view (<q=> or <q =>). Combined with the relevant known quantities (such as the size of the object, the field of view, etc.), using the above formula relationship, you can calculate the distance-related quantity under the condition that the focal length of the lens is known. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What does a long focal length lens mean?
Usually, a focal length of 50mm was regarded as a medium focal length that was close to the normal visual range of the human eye. In digital cameras, lenses with a focal length of 80 - 135mm were called medium-range lenses, while lenses with a focal length of 135mm and above were considered telephoto lenses. Therefore, medium-telephoto lenses were basically commonly used with focal lengths of 70 - 200. However, this boundary was not absolutely fixed. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>