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>
Surveillance camera with a lens
The surveillance camera was just a single video capture device. The resolution and resolution of the lens were higher than that of the computer's video head, but it could not catch up with professional digital cameras or DVs. In reality, cameras and lenses were mostly purchased separately. The user can calculate the focal length of the lens according to the size of the target object and the distance between the camera and the object to determine the required lens. The lens required by each user depends on the actual situation. It cannot be assumed that the camera (head) already has a lens and does not need to be equipped with another lens. The focal length of the lens determined the field of view of the camera. For example, a wide-angle lens was suitable for shooting in a large space and could capture more content. A telephoto lens was suitable for long-distance shooting and could see details in the distance. Indoors, they usually chose short focal lenses, such as 2.8mm or 3.6mm lenses, while outdoors, they chose lenses based on distance. Moreover, different focal length lenses had different imaging effects. Long focal length lenses could see more details of distant objects, but the field of view became smaller and the viewing range became narrower. Wide-angle lenses had a wide viewing range, but it might be difficult to distinguish some details. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Renting a camera lens
There were many ways to rent camera lenses in Dalian. There were some camera equipment rental companies that offered Canon, Nikon, and other brands of cameras and lenses for rent. For example, there were companies that rented Canon 5d3, 5d2, 6d, and other models as well as red circle lenses. The variety was relatively complete and the price was favorable. In addition, some professional photography studios also provided camera lens rental services. These studios had a wide variety of equipment, including single-lens reflex cameras, professional lenses, etc. They would also customize shooting plans for their customers. The scope of services covered Dalian areas. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Professional lens camera
Interchangeable lens cameras were professional in the field of photography. The following are some of the situations regarding professional cameras: The biggest advantage of an interchangable lens camera (including single-lens reflex, mirrorless, rangefinder, etc.) was that it could be used to achieve various shooting needs by changing different lenses. The rich expansibility reflected its professionalism. For example, the Senyang RS af changeable lens set, its national version has been on sale in Jingdong, providing the option of sony e-mount and supporting autofocus, priced at 2899 yuan, it can be manually changed by changing the fixed-focus lens group to switch the focal length, users can freely choose from 21mm F3.5, 28mm f3.5, 32mm F2.8 three modules. Canon's professional cameras, such as the Canon Eos C500, were high-definition cameras, interchangeable lens cameras, and professional positioning cameras. Canon was suitable for Canon's EP lens (including the ES-S lens), Canon's EP Cinema lens (the EP mount), and so on. There were also Djiang's M43 cameras with changeable lenses, such as Djiang's X5 shock-absorbing pan-tilt camera. It was equipped with related accessories such as the 12f2 aperture fixed shaft head and shock-absorbing arm. It had certain characteristics in operation, such as the default manual operation after the rubber wheel was installed. The manual glue turned on the focus assist, and it could focus while moving. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What is a camera lens?
The camera lens was an important part of the camera and had many functions and characteristics. In terms of focal length, there were lenses with different focal length ranges, such as fisheye lenses (7.5 - 13mm), ultra-wide-angle lenses (17 - 24mm), wide-angle lenses (28 - 35mm), standard lenses (45 - 58mm, generally 50mm), medium-long focal length lenses (80 - 135mm), long focal length lenses (200mm, 300mm, 500mm), ultra-long focal length lenses (1000mm and above), etc. According to whether it could be zoomed, it could be divided into fixed-focus lens and zoom lens. The zoom lens could change the focal distance and freely adjust the focal length within a large range, but the image quality was worse than the fixed-focus lens under the same technical level. The aperture of the lens referred to the largest relative aperture, which was the largest aperture. There were large apertures (such as F1.0, F1.2, etc.), medium apertures (such as F3.5, F4.5, etc.), and small apertures (below F8). Different types of lenses had different characteristics in terms of angle of view, depth of field, image quality, shooting range, etc. For example, wide-angle lens had a large depth of field and angle of view, which was conducive to shooting a wide scene in a narrow environment, but the image distortion difference was large. Telephoto lens had a small depth of field and angle of view, which could capture a large image of the scene from a long distance with a small image distortion difference. The compression of perspective relationship shortened the depth of the picture, which was conducive to capturing the image of the combination of virtual and real. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>