The focal length of a lens referred to the distance from the main point of the lens to the focal point. This was an important performance indicator of the lens. According to the length of the focal length of the lens, the lens could be divided into telephoto lens, standard lens, wide-angle lens, and other types. Generally speaking, a long focal length lens had a relatively long focal length, a narrow field of view, a small viewing range, and a small number of scenes. However, each scene occupied a large area in the picture, and it could zoom in on distant scenes so that the distant object would have a larger image on the imaging medium. For example, a long focal length lens was suitable for shooting long-distance pictures, such as shooting a clear moon crater when shooting the moon. A short focal length lens had a shorter focal length, a wider field of view, and a wider viewing range. There were more scenes in the picture, but each scene occupied a small area in the picture. For example, a wide-angle lens could shoot a wide scene at a close distance. The angle of view of a standard lens is about 50 degrees, which is close to the angle of view that a single eye can see without turning the head and eyes. Its imaging effect is basically the same as what we usually see. The focal length of the standard lens of different types of cameras is different. For example, the focal length of the standard lens of a 35mm camera is 40mm, 50mm or 55mm. Read more exciting novels for free
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>
The focal length of the framing lens was related to the focal length of the lens of the framing camera (such as the APS-C frame camera). When comparing a full-frame camera with a cropped camera, the equivalent focal length effect would occur due to the different sensor size. For example, a full-frame 50mm focal length lens was equivalent to a 75mm or 80mm focal length lens when applied to a cropped camera (Nikon/Canon cropped camera equivalent coefficient was 1.5/1.6). This meant that when the lens was used on a cropped camera, the angle of view corresponding to the actual focal length of the lens was equivalent to the effect of a focal length on a full-frame camera. This concept helped to consider the impact of the focal length of the lens on the angle of view and depth of field of the shot according to the camera frame. Different focal lengths had different uses in shooting. For example, the perspective of the 50mm focal length lens was close to the human eye effect, and the 35mm focal length lens had a wider angle of view. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
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>
The 6mm focal length lens had a good balance between field of view and clarity. It not only provided a relatively wide field of view, but also ensured the clarity and details of the picture. The resolution requirement was also relatively moderate. It did not need a high resolution to obtain a satisfactory image quality. He performed particularly well in scenes such as home surveillance and small conference room recording. However, it might still be insufficient in certain situations. In terms of exposure parameters, there were many combinations such as aperture f/5.6, exposure time 1/400, exposure compensation 0EV, etc.(This is only an example combination. There are many different combinations of parameters in practical applications to meet different shooting needs). At the same time, in application scenarios such as monitoring equipment, different 6mm focal length lenses may also be accompanied by other features, such as the horizontal rotation angle of the pan/tilt function of 355°, the vertical rotation angle of 90°, and the visual range of 360°. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The focal length was a measure of the concentration or dispersion of light in an optical system. The distance between the focal point and the center point of the mirror was the focal length, and the unit was "mm." If there was only one number on the lens, it was a fixed-focus lens. If there were two numbers, it was a zoom lens. Lenses with different focal lengths had different characteristics and functions: 1. ** Super wide-angle lens (focal length less than 24mm)**: - [Special characteristic: Large viewing angle] - [Function: It is suitable for shooting large scenes such as scenery and architecture. It can accommodate more elements in the picture, but the proportion of each element in the picture is small. At the same time, it is easy to produce distortion effects. It is difficult to control the effect in close-up shots.] 2. ** 24mm/28mm wide-angle lens **: - [Special characteristic: A wide viewing angle.] - [Function: Commonly used for shooting scenery, architecture, and other large scenes. It can also include many objects, but it may include unnecessary elements during composition, causing the picture to be messy.] 3. ** 35mm-85mm standard lens **: - [Special characteristic: The shooting effect is close to what the human eye can see. It looks natural.] - [Function: It is widely used in portrait shooting, with 35mm, 50mm, and 85mm being common focal lengths.] 4. ** 85mm lens (fixed-focus lens is outstanding in portrait photography)**: - [Special characteristics: Shooting angle of 28 degrees. With a large aperture, the background can be simplified, the character can be highlighted, and the background blurring effect is good. The distance from the whole body to the close-up is about 1.5 meters to 5 meters. The image quality is good, but the angle of view is fixed.] - [Effect: Excellent performance in portrait photography, regarded by many professional photographers as the king of focal length.] 5. ** Telephoto lens above 200mm **: - [Special characteristics: Narrow angle of view, can zoom in on distant objects, can perform a reduction process on the image to eliminate messy elements, has a strong sense of background compression, can make the main body and the background closer in perception, and the longer the focal length, the less obvious the face distortion effect. When shooting a portrait, the facial features will be slightly flattened.] - [Usage: Commonly used for shooting birds, sports events, and other long-distance subjects.] <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The focal length was a key characteristic of a photographic lens. The two were closely related and had many effects on the shooting: * * 1. Relationship between lens type and focal length ** 1. * * Wide-angle lens ** - A lens with a focal length of less than 35mm was a wide-angle lens. This type of lens had a wide angle of view and was suitable for shooting scenery, buildings, and other scenes that required a large angle of view. For example, when taking pictures of vast natural scenery or magnificent buildings, the wide-angle lens could bring more scenes into the picture. 2. * * Standard Shot ** - A lens with a focal length of about 50mm was considered a standard lens. Its angle of view was close to what the human eye could see, and it was often used for portraits and everyday photography. When using a standard lens to shoot a portrait, the proportions and space of the person were more natural. 3. * * Telephoto lens ** - Lenses with a focal length of more than 70mm were considered telephoto lenses and were suitable for long-distance shooting, such as wild animal photography and sports photography. A telephoto lens could make a distant subject look bigger in the picture, as if it was closing the distance between the photographer and the subject. * * 2. The effect of focal length on the lens shooting effect ** 1. * * Perspective * - The shorter the focal length, the wider the angle of view of the lens, allowing it to capture a wider scene. For example, when using a lens with a smaller focal length to shoot a city street, it could cover more street buildings and people. On the contrary, the longer the focal length, the narrower the field of view, which could make distant objects look closer. For example, when a telephoto lens was used to shoot wild animals, it could highlight the main body of the animal while blurring the background. 2. * * In terms of depth of field ** - A lens with a shorter focal length usually has a deeper depth of field, which means that a larger area of the picture will remain clear. This was very useful in landscape photography, such as using a wide-angle lens to shoot a large sea of flowers, from the flowers nearby to the mountains in the distance. The long focal length lens would produce a shallow depth of field, blurring the background and helping to highlight the subject. In portrait photography, the long focal length lens could clearly highlight the main character and blur out the messy background. 3. * * X-ray Transfiguration ** - Wide-angle lenses (short focal length) were prone to perspective distortion, making the object in the picture look farther or flatter than it actually was. For example, when shooting a person at close range with a wide-angle lens, the proportion of the facial features of the person may be out of balance, and the parts close to the lens (such as the nose and mouth) may appear larger than normal. The long focal length lens could better maintain the proportional relationship between the objects and reduce distortion. It was more suitable for shooting scenes that needed to accurately represent the shape of people or objects. * * 3. The relationship between the focal length indicator and the lens type ** - If the focal length label on the lens had two numbers, it meant that the lens was a zoom lens, and its focal length covered the focal length between the two numbers. For example, the 17 - 40mm logo meant that this was a zoom lens, and the focal length varied between 17mm and 40mm. If the focal length indicator on the lens only had one number, it meant that the lens was a fixed-focus lens. For example, a lens with a focal length of 50mm was a fixed-focus lens. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
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>
There were many options for the focal length of the auto show lens. The following were some common ones: 1. ** Telefocal length- 70 - 200**: - The imaging quality was extremely high. At the auto show, when some of the stops did not allow the audience to go on stage, the advantage of the telephoto lens was revealed. This focal length covered a long area, allowing him to attack and defend. He would not miss the opportunity to shoot because of the lack of focal length. He looked professional on the outside, and the models would usually take the initiative to pose when they saw him. 2. ** Fixed focus lens-85mm **: known as the "portrait weapon", with f1.4 and f1.8 focal lengths to choose from. If the budget was sufficient, one could choose an F1.4 model. If the budget was less, one could choose an F1.8 model, which was enough for shooting models. 3. ** Fixed focal lens-50mm **: This focal length fixed-focal lens has a long history. In the last century, it was mass-produced because of its simple design, easy manufacturing, and guaranteed image quality. There were large aperture versions such as f1.4 and f1.8, which were convenient to use when the light was not good. It could provide a range of vision equivalent to that of the human eye. The characters on the screen were stable and square without obvious distortion, but the images might lack impact. 4. ** Fixed focus lens-35mm **: This is also an option for auto show shooting. 5. **14 - 24mm **: For example, Nikon's 14 - 24mm F2.8 lens. The 14mm lens could be used to shoot multiple models and the overall stage effect. For example, the overall effect of shooting the stage + model + car at the auto show was very good. However, the distortion of the 14mm lens was obvious. When shooting a single model, it was necessary to pay attention to placing the upper body (head) of the model in the middle of the picture (the smallest distortion), and the legs were placed at the edge. The overall stretching effect was better, and it was best to cooperate with the beautiful booth to shoot a single model. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
There were many types of Nikon 50-focal lenses. For example, the Nikon 50mm 1.4D was a single-lens reflex lens produced in China with a gross weight of 320.00g. The AF-S 50mm f/1.4G standard fixed-focus lens weighed about 280g. The lens structure was 7 groups of 8 pieces, the minimum f/stop was 16, and the closest focusing distance (macro setting) was 0.45m. The Nikon Z 50mm F1.8S had a reference price of 3699 yuan. It had high sharpness at full aperture, and good control of dispersion and phase difference. The Nikkor Z 50mm f/1.2S was the autofocus lens with the largest aperture among Nikon's Z-mount lenses. The lens body was larger, the filter diameter was 82mm, the size was about 89.5x150mm, and the weight was about 1090g. The structure adopted 15 sets of 17 lenses. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The focal length of the lens is the distance from the main point of the lens to the focal point. It has the following characteristics and functions: - ** Image size **: The length of the focal length of the lens determines the size of the image of the object on the imaging medium (film or CCTV, etc.), which is equivalent to the scale of the object and the image. When shooting the same subject at 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. - ** Field of view **: The length of the focal length will affect the field of view. Different focal lengths correspond to different fields of view. - ** Depth-of-field **: The length of the focal length has an impact on the depth of field. Depth-of-field refers to the distance between the front and back of the object that can be obtained from the front of the camera lens or other imagers. - ** Picture perspective **: The length of the focal length of the lens will affect the perspective of the picture, thus affecting the visual effect and spatial sense of the picture. The focal length of a camera lens varied greatly according to its use. Some were as short as a few millimeters, some were as long as ten millimeters, and some were as long as a few meters. The focal length of the lens was divided into the image focal length and the object focal length. The image focal length was the distance from the main surface of the image to the focal point of the image, and the object focal length was the distance from the main surface of the object to the focal point of the object. The focal length of the camera lens usually referred to the image focal length. The focal length was the division of the focal length of the lens. Different focal lengths included super wide angle, wide angle, standard, medium focal length, medium telephoto, telephoto, super telephoto, etc. Different focal lengths also had different performances in terms of imaging. For example, if a wide-angle lens (21mm-40mm focal length) was used to shoot close-up portraits, objects closer to the lens would be magnified, which might cause the mouth, nose, and arms closer to the lens to be magnified and deformed. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>