The difference between cell phone resolution and camera focal length
The phone's resolution was an important indicator to measure the clarity of a photo. It represented the number of basic components of a photo. For example, the width of the iPhone 6 was 3264, the height was 2448, and the total resolution was about 7,892,000 (the manufacturer generally promoted it to be 8 million). In theory, the higher the resolution, the clearer the image. However, too high a resolution would cause the unit size of the image to become smaller, and the interference between the images would become larger, causing more noise. The focal length of a camera was divided into sections of the focal length of the lens. It was generally divided into super wide angle, wide angle, standard, medium focal length, medium telephoto, telephoto, super telephoto, and so on. Lenses with different focal lengths had different focal lengths and angles of view. For example, a super wide-angle lens was below 20mm, a wide-angle lens was 21mm-40mm, and a standard lens was 41mm-60mm. Lenses with different focal lengths were suitable for different shooting scenes and shooting needs. In summary, the phone's resolution was mainly related to the clarity of the photo, while the camera's focal length was mainly related to the focal length range and angle of view of the lens. The two were different concepts that affected the shooting effect of the phone or camera from different aspects. Read more exciting novels for free
What's the focal length of a typical cell phone camera?
In the field of smart phones, the focal length of the main camera was usually 25mm-28mm, and the focal length of the ultra-wide-angle camera was about 16mm. Generally speaking, a lens with a focal length between 24mm and 35mm was a wide-angle lens. In the field of smart phones, the main camera was often called a " wide-angle main camera." The focal length of 50mm was about twice that of a wide-angle main lens. It was an equivalent 2X telephoto lens and had a better effect in portrait photography. Moreover, the focal length of a traditional telephoto lens could only reach about 90mm, which was equivalent to a telephoto lens of about 3X. In addition, different focal lengths had a certain equivalent relationship with the focal length of the DSLR. For example, 0.5x focal length was equivalent to the 13mm focal length of the DSLR, and 1x focal length was equivalent to the 26mm focal length of the DSLR. The lens of a single-camera phone was usually a wide-angle lens with an equivalent focal length of about 22mm-30mm. <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>
The difference in the focal length of the surveillance camera
For surveillance cameras, there were many differences in focal length: 1. ** Image size **: The focal length affects the image size of the captured image. 2. ** Field of view **: - The larger the focal length, the smaller the field of view. With the lens as the apex, the angle formed by the two edges of the largest range of the object image through the lens would be smaller. The range of the viewing angle would be smaller, but the relative details would be clearer. - The smaller the focal length, the larger the field of view, and the larger the range of view, but the lower the degree of recognition. 3. ** Depth-of-field **: Depth-of-field refers to the distance between the front and back of the object being photographed when the camera lens can obtain a clear image. The depth of field was different at different focal lengths. 4. ** Surveillance Distance **: - The larger the focal length, the farther the surveillance camera could shoot. It was suitable for monitoring distant targets or large areas, such as outdoor rectangular areas. - The smaller the focal length, the closer the surveillance shooting distance. It was suitable for monitoring closer targets or areas with a small range and a large viewing angle, such as indoor square areas such as family living rooms and small shops. <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>
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>
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>
The difference between a cell phone camera and a DSLR
There were differences between cell phone cameras and DSLR cameras in the following aspects: ###1. Operation Mode and Specialization 1. ** Ease of operation ** - Mobile phones had evolved from fully automatic photography to adding professional manual mode, but the overall operation was easier than DSLR. The phone was easy to use and was very convenient for the general public to record daily life scenes. They did not need too much photography knowledge to take qualified photos. - The operation of a single-lens reflex camera was more complicated and required a certain level of photography knowledge. For example, a single-lens reflex camera could accurately set the shutter, aperture, sensitivity, and other parameters according to the shooting needs to meet different shooting creativity and environmental requirements. For professional photographers or photography enthusiasts, it could better control the shooting effect, but for beginners, the learning cost was high. 2. ** Manipulation ** - Even though the shutter speed, aperture, and so on could be adjusted in the professional mode, the maneuverability was still inferior to that of a DSLR in some special situations. For example, in some scenes where the shutter speed was extremely high, the DSLR camera could adjust the shutter speed more accurately. - The lens of the single-lens reflex camera could be changed, and different lenses were suitable for different shooting scenes (such as wide-angle lens for shooting large scenes, telephoto lens for shooting long-range or close-up, etc.), which greatly increased the flexibility and professionalism of the single-lens reflex camera in different scenes. The phone lens was relatively fixed. Although there was a multi-camera configuration, there was still a gap between the imaging and the real optical lens. ###2. Image Effect 1. ** Image Quality ** - DSLR cameras had a larger color range than cell phones. Even though there were many smart phones that could provide high-quality images, the settings of the DSLR camera could be adjusted freely to ensure that the images were better. - Mobile phones were limited by their hardware, and their imaging was limited. For example, the size of the sensor was small, mostly between 1/2.3 and 1/1.5, while the size of the sensor of the DSLR camera was larger, which allowed the DSLR to capture light better in low light environments, reduce noise, and obtain clearer and more detailed images. 2. ** Void Effect ** - Although mobile phones now had the concept of depth of field to produce the effect of background blurring, the effect of the blurring of the background was either not good or not natural enough. It relied heavily on the calculation of the mobile phone chip. The DSLR camera could produce a natural depth of field effect through the optical lens. Whether it was the blurring of the background or the blurring of the background, it could better meet the needs of close-up shots such as portraits and flowers. 3. ** Zooming ability ** - Most mobile phones had digital zooming, which was a loss of zooming. Zooming when shooting long-range shots would cause the quality of the image to decrease. Although some mobile phones achieved a non-destructive zooming, the magnification was limited. - The lens of the DSLR camera was an optical lens. Its biggest selling point was its non-destructive zooming. Even if it was shooting a distant view such as a crater on the surface of the moon, as long as the focal length of the lens was enough, it could be clearly recorded. 4. ** Depth of field compression effect ** - Some phones could achieve better depth of field compression, but some phones couldn't, which was related to the phone's sensor and lens. When shooting with the optical telephoto lens of a single-lens reflex camera, it was easy to obtain the depth of field compression effect, making the subject in the photo feel closer. 5. ** Shutter performance ** - Mobile phones used electronic shutters, and there was an obvious lag after the high-speed shutter was pressed, which was not conducive to capturing photos and made it easy to miss important pictures. Moreover, the continuous shooting speed of a mobile phone was slower than that of a single-lens reflex camera. - DSLR cameras used a mechanical shutter, and they could shoot immediately when the shutter was pressed. As long as the shutter speed was fast enough, they could quickly capture moving objects without smearing. ###3. Device Characteristics 1. ** Universal and Portable ** - There were many smart phones, more than the world's population. It was very common for everyone to have one. Moreover, the mobile phone was light and portable. It could be placed in the shirt pocket. When it was carried, it was almost impossible to see that it was carrying a device. There was no need to bring additional accessories when traveling. - DSLR cameras were still the main shooting equipment for professional photographers. Although many amateur photographers owned them, they were not as common as mobile phones. Moreover, the DSLR camera was cumbersome and had a large number of accessories (such as extra batteries, lenses, flashlights, tripods, etc.). Not only was it inconvenient to carry it when traveling, but there was also the risk of losing the accessories. 2. ** Ease of sharing information ** - It was very easy for mobile phones to share photos and videos taken through social media platforms. They could be transmitted directly. - Although DSLR cameras had connection options such as Wi-Fi, Bluetooth, and Bluetooth to share information, they also needed a compatible mobile application to share images and photos on social media, or they had to be connected to a laptop, tablet, or PC to share. Earlier DSLR cameras could only be connected through a data cable, and the high quality of the photos was also a test of the transmission speed. 3. ** Picture editing convenience ** - The phone came with an image editing function, and you could also download a large number of high-quality image editing applications from the Internet for free, such as Snapseed, Instagram, SloPro, CloudSplash Felix, etc., which could make a variety of creative editing of images. - DSLR cameras either used the built-in editing function or transferred the images to a laptop or PC and used professional photo editing software (such as Photoshop) for editing. It was not as convenient and fast as a mobile phone. 4. ** Cost ** - Although high-quality smart phones were more expensive, they were much cheaper than high-quality single-lens reflex cameras. Other than the body, the lens of the DSLR camera was expensive. After purchasing it, one usually needed to choose multiple lenses. They also needed to spend a lot of money on cleaning the camera and other services to protect it from weather changes. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The focal length of a direct-focus camera
In direct-focus photography, when the eyepieces of the telescope were removed, leaving only the main mirror, the lens of the DSLR was also removed to expose the LCD sensor, and then the telescope was directly connected to the DSLR (may require an M42 ring). At this time, the focal length of the telescope's main mirror was the focal length of the lens. For example, when using the MK20240 for direct-focus photography, the focal length was 2400mm, so the focal length of the lens was 2400mm. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What's the focal length of the camera?
There were many values to choose from for the focal length of the camera. The common ones were 2.8mm, 3.6mm, 4mm, 6mm, 8mm, 16mm, 32mm, and so on. Cameras with different focal lengths had different monitoring ranges, angles, and distance characteristics. Generally speaking, the smaller the focal length, the larger the monitoring angle, the closer it would be. For example, the 2.8MM lens could reach 100 degrees, but the distance was about 5 meters. The larger the focal length, the farther the monitoring angle would be. For example, the 12mm lens could reach 26 degrees, and the distance could reach about 35 meters. In addition, when selecting the focal length, it can also be determined by the calculation formula f = h×D × H (where f is the focal length, h is the horizontal size of the sensor, D is the object distance, and H is the object width) according to the parameters such as the object distance, object width, and the sensor width. It can also be selected by estimation according to the use scene. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>