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. Read more exciting novels for free
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>
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 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 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>
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>
Staircase camera focal length
For a relatively narrow environment such as stairs, a 2.8mm focal length camera could generally be used. Its field of view was larger and the range that could be seen was the largest. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The focal length of the surveillance camera
In an optical system, the focal length of the surveillance camera was the distance from the optical center point of the lens to the camera's CCD-based/CMOS-based sensor. It can also be understood as the distance from the center of the lens to the focal point of the light when parallel light is incident. The size of the focal length determined the image size, field of view, and depth of field of the surveillance image. Generally speaking, the larger the focal length, the farther the view, and the smaller the field of view. The smaller the focal length, the closer the view, and the larger the field of view. The focal length of mainstream surveillance cameras was generally 2.8mm, 3.6mm/4mm, 6mm, 8mm, 12mm, 16mm, etc. Some even had a zooming function. Cameras with different focal lengths are suitable for different monitoring ranges. For example, for situations where the monitoring range is small and the viewing angle is large, such as a family living room, small shops, etc., you can choose a surveillance camera with a smaller focal length.(For example, a 3.6mm or 4mm focal length camera can have a viewing angle of 75°-90 °, an effective monitoring distance of more than 5 meters, and can cover 40 - 80 degrees of space); for a larger monitoring range (such as a space of 10m * 10m), you need to choose a surveillance camera with a larger focal length. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Phone camera focal length
The focal length of a cell phone camera could be categorized into many categories and uses: - ** Ultra-wide-angle lens **: A lens with a focal length between 6mm and 16mm is called a "fisheye lens". It is an extreme ultra-wide-angle lens. The angle of view is more than 180 degrees, and some can reach 230 degrees. It is more entertaining. The "ultra-wide-angle camera" in the smartphone had a focal length of about 16mm, which was usually 0.6 times the focal length of the main camera. The ultra-wide-angle camera mode in the camera APP was also known as "0.6X zoom." It was suitable for shooting tall buildings and scenery. After optimization, it could be used as a "super macro lens." - ** Wide-angle lens **: A lens with a focal length between 24mm and 35mm is a "wide-angle lens". It has a smaller focal length and a wider angle of view. It can record a wide space and is called a "master lens". The focal length of the main camera in the field of smart phones was usually 25mm-28mm, also known as the "wide-angle main camera." The 1X focal length (main focal length) had good image quality, suitable for shooting portraits, buildings, scenery, documentary and many other scenes. - ** Portrait lens (standard lens)**: A lens with a focal length between 35mm and 70mm is considered a "standard lens". Among them, the 50mm focal length has the best effect. When shooting portraits, the distortion is small and the background blurring effect is good. It can highlight the main body of the character. In the field of smart phones, the 50mm focal length is about twice that of the wide-angle main lens. It can be called a portrait lens or an equivalent 2X telephoto lens. - ** Telephoto lens **: Generally speaking, a focal length of 70mm or above is a "telephoto lens", but the standard for smart phones is lower. A focal length greater than 50mm is considered a telephoto lens. The focal length of the telephoto lens of a traditional mobile phone could reach up to about 90mm (equivalent to a 3X telephoto lens). Different phone models had different focal lengths. Single-camera phone lenses were mostly wide-angle lenses with an equivalent focal length of about 22mm-30mm; multi-camera phones often used wide-angle lenses as the main camera, combined with ultra-wide-angle or telephoto lenses. For example, the 0.5x focal length was equivalent to the 13mm focal length of the single-lens reflex, which was suitable for shooting large scenes; the 1x focal length was equivalent to the 26mm focal length of the single-lens reflex, which was suitable for portraits and cultural documentary shooting. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
camera focal length factor
For digital cameras, because the area of their CCDs or sensors was smaller than that of traditional 135 cameras (35mm full-frame), when using the same lens, the imaging area was smaller than that of a film camera, resulting in fewer scenes falling on the imaging element than traditional 135 cameras. This gave rise to the concept of focal length coefficient. The focal length coefficient was calculated as the ratio of the length of the film to the length of the corresponding side of the CCD. For example, if the film is calculated as 24mm, the corresponding side length of the CCD-side is 12mm, and the coefficient is 2. When using lenses on different frame cameras, the focal length needed to be converted by a factor. For example, the Canon APS-C camera needed to be multiplied by a factor of 1.6. For example, a 100mm fixed-focus head hung on the APS-C body would have an equivalent focal length of 160mm, while the Canon APS-C classic head's actual focal length of 18 - 135mm would be 28 - 216mm. The focal length coefficient made it so that when the lens was used on different frame cameras, although the angle of view had an equivalent change, the depth of field and perspective effect were still the same as the original lens. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
90 focal length lens group photo
When taking group photos, a 90mm focal length lens was a more suitable choice. The standard lens had many advantages when taking group photos, such as the smallest distortion and the closest to the human eye's visual perception. When using a 120 medium format 6×7 camera to take a group photo of more than 500 people, using a 90mm lens could achieve better results. However, when using this focal length lens to take a group photo, one also had to consider other factors such as shooting distance, aperture, shooting time, queue position, etc., in order to take the ideal group photo. For example, it is recommended to choose soft natural light when shooting, such as 9 - 10 a.m. or 4 - 5 p.m.(It needs to be adjusted according to the season and regional differences). It is best to use a cloudy morning, and the direction of the light is best to be in the light. In terms of queue position, when there are more people, they can be arranged in a square array (for example, 50 - 100 people can be arranged in 4 - 5 rows). The height of the front and back rows should be reasonably arranged by chairs, stools, steps, etc. to avoid blocking. It is recommended to use a small aperture such as F11 or F16 (different cameras may have different aperture ranges). <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>