Ordinary camera lens
Generally speaking, photography lenses could be divided into the following categories: * * 1. Standard zoom lens ** 1. * * Focus range and common models ** - The focal length usually started from 24mm or 28mm, and covered the medium telephoto range of 70mm to 120mm. The common ones were 24 - 105mm, 24 - 70mm, 28 - 70mm, and so on. 2. * * Eligible Groups and Strengths ** - It was a good choice for beginners because most cameras came with standard zoom lenses. It could shoot a wide range of subjects, such as portraits, scenery, culture, and cities. It was easy to use and could meet most shooting needs. Even experienced photographers often used it. * * 2. Telephoto zoom lens ** 1. * * Focus definition and applicable scene ** - Generally speaking, a lens with a focal length of more than 200mm was called a telephoto lens. If you were shooting portraits, flowers, plants, street culture, and other topics, 70 - 200mm f/2.8 and 70 - 200mm f/4 were good choices. If you like shooting birds, lotus flowers, long-distance scenery, and other topics, you need a focal length of more than 300mm, such as 70 - 300, 100 - 400, and so on. 2. * * The camera advantage ** - It had a long focal length and could be shot without disturbing the subject. It could also bring a good blurring effect. It was suitable for street culture, bird hunting, and shooting flowers and plants. * * 3. Fixed focus lens ** 1. * * Commonly seen focal length and advantages ** - Common focal lengths were 28mm, 35mm, 50mm, 85mm, and so on. The fixed-focus lens had good imaging quality and a large aperture. It was very friendly to portraits. 2. * * Disadvantages and suggestions ** - It couldn't be zoomed, and the photographer needed to move to adjust the image. This tested the photographer's skill. If you are interested in fixed-focus lenses, you can try buying cheaper fixed-focus lenses, such as Canon's 50mm f/1.8, Nikon's 24mm f/1.8, 35mm f/1.8, 50mm f/1.8, etc. * * 4. The characteristics of lenses with different focal lengths (135-cm camera lens as an example)** 1. * * Fisheye lens (7.5 - 13mm)** - The camera had a large angle of view and a large depth of field. It could shoot a wide scene in a narrow environment. It could make the depth of the scene have a strong ratio of near to far. The image had a strong sense of perspective, but the image distortion was large, especially at the edge of the image. When shooting at close range, one had to pay attention to distortion. 2. * * Super wide-angle lens (17 - 24mm)** - A large depth of field was good for showing the subject with a large depth. A large angle of view could shoot a wider scene with a long depth of field. However, there was also the problem of large image distortion. 3. * * Wide-angle lens (28 - 35mm)** - It had a certain depth of field and a relatively large angle of view. It was suitable for shooting scenes that required a sense of space. 4. * * Standard lens (45 - 58mm, generally 50mm)** - Its focal length was close to the diagonal of the film frame used, and its angle of view was close to that of the human eye (about 50 degrees). The image quality was relatively high, and it was widely used in various photography. 5. * * Medium and long focal length lens (80 - 135mm)** - It has a good performance in portrait photography and can use perspective to produce special effects. 6. * * Long focal length lens (200mm, 300mm, 500mm)** - The small depth of field was conducive to capturing the image of the combination of virtual and real; the small angle of view could capture a large image of the scene from a long distance, and when shooting objects that were not easy to approach, it could be shot from a distance without interference; the perspective relationship was greatly compressed, and the image distortion was small, which performed well in portrait photography. 7. * * Ultra-long focal length lens (1000mm and above)** - It was suitable for shooting extremely distant objects. * * 5. Aperture of the lens ** - The aperture of the lens referred to the largest relative aperture, which was the largest aperture. It could be divided into large apertures (F1.0, F1.2, F1.4, F1.7, F1.8, F2.0, F2.8), medium apertures (F3.5, F4.5, F5.6), and small apertures (below F8). * * 6. Comparing the image quality of a zoom lens and a fixed-focus lens ** - Under the premise of the same quality and technical level, the image quality of a zoom lens was always worse than a fixed-focus lens. Read more exciting novels for free
The difference between a digital camera and an ordinary changeable lens
There were many differences between digital cameras, which included ordinary cameras with changeable lenses. ** 1. In terms of camera lens ** 1. ** Commonality of changing lenses ** - Most ordinary digital cameras couldn't change the lens. The lens was fixed to the body of the camera. - Digital cameras with changeable lenses (some special types) could change lenses to adapt to different shooting needs, such as different focal lengths and aperture requirements. 2. ** Relationship between autofocus system and lens ** - If the digital camera with an changeable lens uses the contrast focusing method (the focusing method of some digital cameras with changeable lenses), the focusing speed and accuracy may be affected, especially when the size of the sensor is large, it is easy to cause the bellows phenomenon (that is, the focus is moved back and forth to determine the focus position). - DSLR digital cameras (a typical type of digital camera with an interchangeable lens) mainly relied on phase difference AF-focusing, and there was a fundamental difference in autofocus performance from some digital cameras with an interchangeable lens. ** 2. Light-sensitive material ** 1. ** Photosensitive Material size ** - Ordinary digital cameras used a relatively small area of the CCD. - Most digital single-lens reflex cameras (also a type of camera that could change lenses) used two-thirds of the full-frame as a light-sensitive material. A few high-end products could achieve full-frame (the same size as 35mm film), and the area of the light-sensitive material was several times larger than that of ordinary digital cameras. 2. ** Image related performance ** - Due to the small size of the light-sensitive material, the noise control of ordinary digital cameras was poor. - Due to the large area of the light-sensitive material, DSLR cameras generally had very little noise. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What is the lens of the camera lens?
Based on context alone The lens of the camera lens was made up of many different types of lenses. This included a concave lens, which had a thick middle and thin edge structure. It had a converging effect on light, which helped to focus the light on the imaging plane, making the image clear. There were also concave lenses, which were thin in the middle and thick at the edges. They had a diffusing effect on light and were often used to correct aberrations. In addition, there were also aspheric lenses. These lenses were not the traditional spherical shape. They could better correct aberrations, improve image quality, and reduce image distortion and blurring. They were widely used in modern camera lenses. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
camera lens
A lens was an optical component composed of two concentric spherical surfaces surrounding a transparent medium (such as glass). It was an important component of a camera lens. It was composed of different focal lengths, lenses, and segments. Its main function was to form images, gather light, and obtain a parallel light source. It could bend and refracted light. Different focal lengths of the lens and the use of optical methods could change the perspective effect of the picture. A good lens could make the images and images clearer and more delicate. The lens of a camera could be divided into two categories: a concave lens (thicker in the middle than the edge) and a concave lens (thinner in the middle than the edge). In surveillance cameras, there are many different specifications of lenses, such as lenses with different angles (such as 9 degrees, 15 degrees, 30 degrees, etc.), different diameter, different lamp beads (such as 3030 lamp beads, 3535 lamp beads, etc.), and there are differences in materials, processing technology, and imaging effects. Some were made of optical-grade PC material and manufactured through high-precision aspheric optical processing technology. They had the characteristics of uniform light spots and no dark corners, which could effectively improve the image quality and make the camera better in different scenes to meet more needs. In addition, there was also the emerging technology of superlens technology, which used traditional semiconductor processing technology to build nanostructures on a flat surface to create lenses. This lens was very thin, only a few hundred millimeters thick, about twice the thickness of a human hair. It could also integrate the functions of multiple curved lenses into one device, helping to solve the problem of space constraints. It might bring new development directions for camera lens technology. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The camera lens changed to a projection lens
Some data showed that the telephoto projection could be used to change the camera lens into a projection lens, and a size image could be projected at a distance of 1.5 meters. He could also use a flashlight as the film's back light and a Nikon lens as the projection lens to make a simple projector and project the reverse film on the wall. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The camera lens is expensive
In the field of photography, expensive lenses had their value. Generally speaking, more expensive lenses had higher performance in terms of optical quality, workmanship, and performance. For example, in the field of medium and long focal length lenses, Canon's RF70 - 200mm f/2.8L IS USM was priced at 16999 yuan, and the Sony70 - 200mm F2.8GM OSS II was priced at 18999 yuan. These lenses were expensive, but they could provide better imaging results, excellent focusing performance, and good durability on their respective cameras. However, with the changes in the photography market, the relationship between price and value did not completely follow the traditional principle of "you get what you pay". In the micro-monocle era, although some high-end lenses had improvements such as quieter focusing, better design, and improved electronic functions, compared to similar lenses in the DSLR era, users felt less about the improvement in optical quality, but the price generally rose. Some of the affordable entry-level lenses, such as the 50mm f1.8 lens, were no longer as affordable as before. Branded lenses of this size were even hyped up to three times the release price. 24 - 105mm f4 or similar lenses were nearly twice as expensive in the micro-single era as in the single-lens reflex era. Although the optical quality had improved, there was no particularly huge breakthrough. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The lens and camera interface
The lens and camera interface was a component used to connect the lens and the camera. Suzhou Ouka optical instrument factory specialized in the production and development of a camera interface, this interface can be connected to different brands and models of lenses, so that the camera can be used normally. There are many types of industrial camera cable ports: - **USB port **: It is a commonly used port for digital cameras. It can directly output digital image signals. USB was the full name of Universal serial bus. The interface was 4-pin, including 2 power cables and 2 signal cables. There were different versions of USB. The early USB2.0 interface was convenient and widely used, but the transmission rate was slow (480Mbit/s), the communication distance was short (5m), and the band width was mostly used for image transmission (80%). The transmission required the CPU to participate in management and consumed a lot of resources, and the interface was unstable. USB3.0 added two sets of data lines on the basis of USB2.0, which were backward compatible. The transmission speed was increased to 4.8Gbit/s, and the communication distance was extended to 10m. However, the transmission distance was still relatively short. USB interface cameras were easy to use and had a wide range of ports. They were widely used in microscopes, scientific research experiments, portable equipment, and other industries. At present, USB Type Micro-B ports were the mainstream on industrial interface cameras. In the future, USB Type C ports might be popularized. - ** IMEE1394 (Firewire Interface)**: It is a high-speed serial bus. It supports hot swapping, real-time data transmission, and uses a bus structure. It is widely used in the industrial field. It has good protocol and coding methods, and the transmission speed is stable. The 1394a's maximum transmission speed was 400mps, and the 1394b's maximum transmission speed was 800mps (3.2mps was relatively rare). Its interface was divided into 4-core and 6-core. The 4-core contained two pairs of data cables, and the 6-core had a set of power cables in addition to the data cable. This interface did not require a controller and could be used for peer-to-peer transmission. The 1394a's maximum transmission distance was 4.5 meters, and the 1394b's transmission distance was usually 10 meters (100 meters, 100 Mbit/s, when the data rate was reduced). However, the interface's penetration rate was low and it had been slowly eliminated by the market. - **Camerlink interface **: A digital image signal communication interface protocol introduced by the Aia Association. It is a serial communication protocol that uses the LVVS interface standard. It was developed from the Channel Link technology, adding the transmission control signal and defined the relevant transmission standards. The protocol used the MDR - 26-pin connection or the SAR- 26-pin connection, which had high speed (up to 6400Mbps), strong anti-interference ability, and low power consumption. However, it required a separate CameraLink interface, which was not portable, expensive, and rarely used in practical applications. - ** Gige Giga-bit ether interface **: created and promoted by Aia. It is a camera interface standard developed based on the Giga-bit ether communication protocol. It is suitable for industrial imaging applications. It can transmit uncompressed video signals over the network and can use low-cost cables to transmit images over long distances. In addition, in the field of machine vision, other data transmission ports were also developed: - **CoaXPress (CXP) interface **: launched in 2008, supports high-speed imaging applications, uses 75 Omega coax cable, supports data transmission speed of up to 6.25Gbit/s per channel, and can increase the transmission rate of multiple channels. Each cable can provide up to 13W of power. It requires the "device" and "host" to support the GenICam camera programming interface. However, the cost of installing multi-channel cable components and frame clips on a single-channel coax cable increases rapidly. - **CameraLink interface **: In 2000, it was launched by Aia Association and gradually upgraded.（2.04Gbit/s）、Medium (5.44Gbit/s) and Deca/Extended (6.8Gbit/s). Base uses an ADC- 26 pin, medium/full requires a second cable to double the capacity, Deca/Extended can transmit up to 6.8Gbit/s data, and like the CXP interface, it requires an image acquisition card that is compatible with the CameralLink power supply (PoQL) standard for power supply. It lacks error correction or resend functions. The cable setup was expensive and troublesome. - **GigE Vision standard interface **: It is managed by the Aia Association and allows the use of existing low-cost ether cables, connections, switches, and other components. Copper cables can transmit image data up to 100 meters away, and more data can be transmitted through the switch and optical fiber adapters. It has the potential to create different network topologies. Each camera can be placed on the network independently through an IP address. It can be viewed, controlled, and monitored from any PC on the network. However, the maximum 115mb/s has limitations for certain applications. However, NBUSE-T technology could increase the band width within its framework. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Convex lens of the camera
A concave lens was a lens with a thicker middle and thinner edges. Its main feature was that it could converge light. When parallel rays of light passed through the concave lens, the rays would converge inward, and the focal point would be on the side of the real focal point of the lens. In a camera lens, a concave lens was mainly used to focus the image, reduce the depth of field, and increase the aperture. According to the relationship between the object distance and the focal length, the concave lens could also form different images. For example, when the object distance was greater than twice the focal length, an inverted and reduced real image would be formed on the other side of the lens. This was the imaging principle of cameras and camera lenses. When the object distance was equal to twice the focal length, an inverted and equal real image would be formed on the other side of the lens. When the object distance was between the focal length and twice the focal length, an inverted and magnified real image would be formed. When the object distance was within the focal length, an upright and magnified virtual image would be formed. Moreover, the real image was formed by the convergence of actual light rays. It could be supported by a light screen. The real image and the object were on both sides of the lens, inverted. The virtual image was formed by the reverse extension of the actual light rays. It could not be supported by a light screen, but it could be seen with the eyes. The virtual image and the object were on the same side of the lens, standing upright. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Studio camera lens
In studio photography, different focal lengths had different applications. For Nikon equipment, the 14 - 24mm f/2.8G ED large bulb lens could be used for architectural, landscape, and starry sky photography. It could also be used in studio photography if you needed to shoot large scenes or had special wide-angle effects. The 58mm f/1.4G lens was light and was a portrait killer. It could be used for studio portrait photography. It could take soft out-of-focus, smooth transition, and small contrast portrait photos. In terms of Canon's equipment, the EF35mm F1.4L II USM was described as a universal lens that could be used for studio photography. The RF135mm F1.8L IS USM lens could be used for studio portraits with a controllable index flash. It could be shot well with optical image stabilization. It could also be used for outdoor night scenes with the combination of the EOS R6 Mark II to achieve coordinated image stabilization. The RF85mm F1.2L lens could be used for studio portraits. The photographer would try to shoot with a 1.2 aperture. The two fixed-focus lenses, the RF50mmF1.2L and the RF35mmF1.8, could also be used for studio photography. The 24 - 70mm standard zoom lens, with its F2.8 large aperture, covered both wide-angle and medium-focus focal lengths, was suitable for shooting in a variety of scenes, as well as studio photography. In addition, the size of the studio would also affect the choice of lens. If the studio was large, a medium telephoto lens could be used. If the studio was small, a standard lens or a lens with a smaller focal length might be considered. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Commercial camera lens
In commercial photography, different focal lengths had different uses. For lenses with a focal length of 24 - 70mm, this was the most important lens for commercial photographers. If it was a practical entry-level user, they would generally consider a 24 - 70mm F4 lens, which was practical and cost-effective. Professional photographers would also use this focal length lens because of their work needs. It could cope with most scenes. For example, Canon had different models such as the EF24 - 70mm f/2.8L II USM, EF24 - 70mm f4L IS USM, RF24 - 70mm F2.8L IS USM, and Nikon had AF-S 24 - 70mm F2.8E VR. Different brands and models had different prices and performance (such as weight, feel, image quality, anti-shake, dark angle, distortion, etc.). The 70 - 200mm telephoto lens was mainly used for close-up shots from a distance. In scenes such as conference events, when there was a need for close-up shots and the photographer was a certain distance away from the subject and there was an obstacle in the middle, or to not interfere with the audience's experience, this focal length lens was a good choice. In still life photography, different focal lengths had their own advantages. For example, when using a single-track camera, for close-up and macro shots (such as jewelry, clocks, etc.), the Nikkor AM/ED 210mm f/5.6 lens and the Rodonsde Apo - Ronar 480mm f/8 lens could be used. For general distance shots, the Schneider Symmar-S 300mm lens was more commonly used. If the layout required more extreme perspective, a wide-angle lens as short as 75mm might be used. When using Hasse's 50MP digital back, the 120mm macro lens could produce natural perspective when taking A4-sized photos. Even at close range, the photos were very clear. 210mm and 80mm lenses would also be used. For outdoor shooting, the Nikon D3 was equipped with an older Nikkor 105mmf/4 macro lens (the newer 105mmf/2.8 lens was not recommended because it would produce vertical aberrations), as well as 45mm and 85mm focal length shift-axis lenses. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Choice of camera lens
There were many factors to consider when choosing a camera lens. If it was shooting scenery, from a novice's point of view, although the wide-angle lens had a large scope and could shoot an imposing manner, there were drawbacks such as small changes in the image and difficult to grasp the perspective relationship. In contrast, the telephoto lens might play a greater role in scenery shooting, and the usage rate was higher. It could also take into account topics such as skits and portraits. The choice of fixed-focus and zoom lenses depended on the user's needs and the subject. The fixed-focus lens had better image quality and was suitable for portraits with high image quality requirements, which could produce better blurring effects. The zoom lens was easy to use and was suitable for traveling, street sweeping, and other scenes that required flexible shooting of various subjects. Tianya Mirror was suitable for people who pursued lightness and practicality. It had the characteristics of light weight, wide focal length coverage (from wide-angle to telephoto), and high playability. For example, Tenglong 50 - 400mm, Nikon Z24 - 200mm, Tenglong 50 - 300mm were all good Tianya Mirrors. For portrait photography, the commonly used focal lengths were 35mm, 50mm, 85mm, and 135mm. From a practical point of view, 50mm and 85mm could be chosen first. The 50mm lens could handle both indoor and outdoor shooting. 85mm was the golden focal length for shooting half-body and close-ups. 35mm was suitable for environmental portraits, and 135mm was suitable for close-ups of people. It could separate people from the background very well. In terms of movie lenses, the most important feature was the focus effect. After focusing, the focus would not change during the zooming process. This feature was suitable for live broadcasts and other scenes to avoid out of focus. In addition, lenses with different mounts (such as the EF-mount, the PL mount, the Sony-E mount, etc.) had different prices, performance, and applicable models. It was also necessary to choose a lens based on the actual camera model and other factors. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>