What are the basic parameters of the surveillance camera?
The basic parameters of the surveillance camera were as follows: 1. ** focal length **: The distance between the lens and the sensor. By changing the focal length, one could change the lens's magnification and the size of the captured image. When the distance between the object and the lens is very far, the lens's amplification factor equals to focal length/object distance. The larger the focal length, the larger the magnification, and the closer the distant view, the smaller the image range, and the clearer the details of the distant view. 2. ** Field of view **: In engineering practice, the horizontal field of view is often used to reflect the shooting range of the image. The larger the focal length f, the smaller the field of view, and the smaller the range of the image formed on the light-sensitive element. Conversely, the smaller the focal length f, the larger the field of view, and the larger the range of the image formed on the light-sensitive element. 3. ** Aperture **: Mounted at the back of the lens. The larger the aperture, the greater the amount of light passing through the lens, and the higher the image clarity; the smaller the aperture, the smaller the amount of light passing through the lens, and the lower the image clarity. It is usually expressed as F (luminous flux), where F = focal length (f)/aperture. In the case of the same focal length f, the smaller the F value, the larger the aperture, the greater the luminous flux reaching the CCD-chip, and the better the lens. Read more exciting novels for free
The parameters of the camera
There were many parameters for the camera lens. The following were some common parameters: 1. ** Focus **: It determines the degree of zooming of the lens. A longer focal length was used for long-distance shooting. For example, a telephoto lens could be used to shoot long-distance topics such as sports competitions, wild animals, aircraft, etc., and it could also enhance the background blurring effect. A shorter focal length was used for wide-angle shooting, such as wide-angle lenses for landscape photography, architectural photography, and crowded indoor spaces. 2. ** Aperture **: For example, the main camera of the Vivo X200 Pro is equipped with a large aperture of f/1.57, which helps to take brighter and clearer photos in dark environments. Its periscope telephoto lens has an aperture of f/2.67, which can ensure the clarity and details of the picture when shooting telephoto. The size of the aperture affected the amount of light entering, depth of field, and so on. 3. ** Pieces **: It is one of the important indicators to measure the quality of the camera. For example, the main camera of the Vivo X200 Pro is expected to use a 50-million-pel large sensor, and the periscope telephoto lens is equipped with a 200-million-pel periscope telephoto lens. 4. ** Photosensor **: For example, the sensor of the HD - 3000 camera is a LCD; the main camera of the Vivo X200 Pro has a 1/1.28-inch sensor, and the periscope telephoto lens has a 1/1.4-inch base. 5. ** View angle **: For example, the helmet camera lens is a 3.7mm pinhole lens with a 90-degree view angle. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Focus the surveillance camera
If it was a general non-integrated surveillance camera, the method of adjusting the focal length was as follows: First, remove the camera, check the small screw like parts at the lens and loosen it, then turn the circle on the lens to adjust the focal length. When adjusting the focal length, it was best to take it off and adjust it while facing the monitor screen. If it was inconvenient to take it off, two people were needed. One person looked at the screen and cooperated with gestures or words, and the other person adjusted it next to the camera to achieve the best effect. It could also be adjusted manually. Some surveillance cameras had two buttons that could be rotated. One was used to adjust the distance and the other was used to adjust the clarity. There was another adjustment method: first loosen the fixing screw of the camera's rear focal length adjustment ring; adjust the zoom lens to the maximum telephoto position, and use the focal length adjustment ring on the lens to set the focal length until the image is the clearest; then adjust the zoom lens to the maximum wide-angle position, and turn the rear focal length adjustment ring until the image is the clearest; when switching from telephoto to wide-angle, repeat the above two steps until the image is in focus; finally, after the setting is complete, tighten the rear focal length adjustment ring. In addition, he added a new experience of adjusting the lens. He loosened the screw that fixed the standard lens, adjusted the magnification, and adjusted the lens to a telephoto state. Then, he zoomed in on the distant object, and then adjusted the focal length to make the close-up image clear. Then, he pulled the lens back to the wide-angle state by zooming out. The image he just shot should be a panoramic view. Don't adjust the focal length of this panoramic view (even if the image is blurry, don't adjust it). Go straight to the next step, which is to adjust the back focal length to adjust the image to the best picture. Finally, tighten the small screw of the lens, and the back focal length adjustment is completed. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The surveillance camera on the highway?
The video surveillance on the highway might have a camera function. For example, the violation camera was generally spherical in shape. Its function was to capture and punish the captured vehicle. Many traffic accidents were caused by parking violation. This kind of camera was installed in the no-parking section, and it was also installed in the parking area of the highway bus. Electronic eyes were used to detect illegal behavior while driving, such as running red lights, changing lanes, etc. Although there was no explicit mention of taking photos, detecting these behaviors usually required taking photos for evidence. Therefore, there were video surveillance cameras on the highway. <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>
Basic parameters of DSLR
The following are the basic settings for common DSLR scenes: ** 1. Portrait Shooting ** 1. ** Still Portrait ** - Shooting mode: Aperture priority mode (LV) can be selected, and the aperture is set to a large aperture, such as F2.8 or larger. - Focus: Focus on the person's eyes. - [Light sensitivity: Daytime light sensitivity can be set between 100 - 400.] - [Focus: Use a focal length of 50mm or above.] - [Shooting distance: Depends on full-body, half-body, and headshot.] 2. ** Portrait in motion ** - [Shooting mode: Shutter priority mode (TV), shutter speed set to 1/250s.] ** 2. Scenery Shooting ** 1. ** Ordinary scenery ** - Shooting mode: You can use P or Aperture priority mode, and the aperture is set to F5.6 or smaller. - [Shot: It is recommended to use a wide-angle lens to accommodate more scenery.] - [Light sensitivity: For example, the clear day's light sensitivity can be set to 100, and the cloudy day's light sensitivity can be set to around 400.] - "Picture composition: avoid placing the most attractive scenery in the middle of the picture. You can use the three-point composition, frame composition, symmetrical composition, diagonal composition, white space composition, etc. 2. ** Special parameters (M file) Shooting on a sunny day ** - It had a shutter speed of about 1/200, and a cloudy day with a shutter speed of 400. ** 3. Flower Shooting ** - [Shooting mode: Aperture priority mode (LV)] - "Lenses: You can choose a large aperture lens or a 100-micro lens. The aperture should be large to highlight the main body and make the depth of field shallow, making the picture softer. - [Composing: You can use the central composition or the nine-square composition to place the main body in the center of the picture.] ** 4. Pet Shooting ** 1. ** Method 1 ** - [Shooting mode: P-grade automatic, continuous shooting function activated.] 2. ** Method 2 ** - [Shooting mode: Shutter priority mode (TV). Shutter set at 1/200s or higher.] ** 5. Night Scene Shooting ** - [Shooting mode: Aperture priority mode. Use a small aperture, such as F10 or smaller.] - [Light sensitivity: Normally set to 100.] - Shutter speed: Can be set to 1/30s. - Metering mode: Set it to the evaluation mode (Matrix Metering mode) and reduce the exposure compensation as appropriate. - [Ancestors: With the help of a tripod, you can use the shutter release to shoot.] ** 6. Silhouette Shooting ** - [Shooting Mode: P-file] - Metering: Use spot photography to measure the brightness of the light. Then, add or subtract the exposure according to the actual needs. Place the focus on the bright spot to measure the brightness. The dark part will become a black silhouette. ** 7. Shooting of still small things like flowers, birds, and insects ** - Shooting mode: Aperture priority mode (LV), the aperture is best to be f5.6 or larger. - [Focus: 50mm and above.] - [Shooting distance: Try to shoot within 1 meter, to blur the background.] ** 8. Portrait Shooting at Night ** - [Shooting mode: Aperture priority mode, f8 aperture.] - Light sensitivity: 100 - 400. - "Anciliaries: Use a tripod, set up automatic or custom white balance, and use slow sync flash (the flash flashes once when the shutter is pressed, and flashes again before the end of the exposure. You can't leave when you're shooting). ** 9. Shooting of moving objects ** 1. ** Method 1 ** - When the light is good, use Aperture priority mode (UA). A small aperture below f8 can get a large depth of field; a shallow depth of field can be obtained above f8, and continuous shutter can be selected. 2. ** Method 2 ** - If you want a dynamic effect, use the shutter priority mode (TV), set the shutter to about 1/30, focus, press the shutter, and at the same time, the lens will follow the target at an appropriate speed. In addition, you also need to pay attention to the photo size, format, and image quality settings. In special scenes, you may need to customize the white balance, set the shooting style, choose the appropriate focus mode, and the basic settings such as sensitivity (you can also directly set the sensitivity to the STAR position and let the camera adjust according to the scene) and exposure mode (M, aperture priority, shutter priority). <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
External parameters of the camera
The external parameters of the camera were parameters in the world coordinate system, mainly referring to the rotation and translation matrix between the camera systems, such as the position and rotation direction of the camera. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What are the camera parameters?
The camera's parameters were divided into two parts: 1. * * Internal reference: - focal length (fx, fy, generally equal): It is related to the optical characteristics of the camera lens and affects the zooming in or out of the image. - Coordinates of the principal point (x0, y0, relative to the imaging plane): In the ideal case, the optical axis of the lens passes through the middle of the image, but in reality, there is an error due to the installation accuracy. This is used to describe this error. - Axis tilt (s, 0 in the ideal case): A variable that reflects the difference between the camera's x-direction and y-direction size reduction ratio. It can convert the length measured by the number of pixels into the length measured by other units in three-dimensional space. It can also indicate the difference between the x-direction and y-direction scale transformation. - Distortion parameters (including the distortion of the radius and the direction of the cut): This is used to describe the distortion effect produced when the lens maps a three-dimensional space straight line onto the image. Under ideal circumstances, the lens should map the straight line into a straight line, but there is actually a deviation. 2. * * External reference **: - Rotation Matrix: It is used to describe the direction of the coordinate axis of the world coordinate system relative to the camera coordinate axis. It is used to determine how the world coordinate point will rotate and fall on the camera coordinate point. - Translational Matrix: It described the position of the origin of space in the camera coordinate system, which was the relevant parameters of the world coordinate point after translation to the camera coordinate point. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
camera sensitivity parameters
The parameters related to the camera's sensitivity were the light sensitivity and the minimum illumination. In terms of light sensitivity (USB), the lower the USB, the clearer the photo would be, and the less noise there would be. In the video recording mode, the setting of the sensitivity was related to the camera mode, and the fourth setting was the shutter speed in the camera mode. When the video was being recorded, it became the automatic limit of the sensitivity for time-lapse photography. For example, it could be lowered to 6400 to reduce the value. The minimum illumination is an important indicator to measure the sensitivity of the CCD-based camera. It represents the corresponding environmental illumination when the environmental illumination is reduced to a certain level, so that the video signal level output by the CCD-based camera is reduced to a certain value. For example, when the environmental illumination is reduced to 0.04lx, the output video signal of the CCD-camera is reduced to 50% of the maximum magnitude, then the minimum illumination of the CCD-camera is 0.04x (F1.2), and the minimum illumination of the CCD-camera is related to the maximum relative aperture of the lens used. When providing the minimum illumination of the camera, the relative aperture of the lens during the test should be indicated. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Nightclub camera parameters
To take photos in a dark environment like a nightclub, the camera parameters were set as follows: - Aperture: If you want to ensure the depth of field (clear front and back), the aperture can be set to a small aperture, such as F8 - F13. However, in some special cases, if a large aperture is needed to increase the amount of light, a relatively large aperture value such as f/4.5 (Ref. 3) may be used, or a large aperture lens such as f/1.8 (Ref. 6) may be used to adapt to dark environments. - ** Light sensitivity (USB)**: If the camera has good noise control, such as the Nikon Z6 II (Ref. 6), you can also get a clear picture in dark and night environments with high sensitivity. You can increase the USB. However, in general, the higher the USB, the more noise it may produce. If a tripod or stabilizing device is allowed, try to use a low USB (such as 100 USB) to ensure the quality of the photo (reference 1). However, if you can't use a tripod and you want to avoid blurring the photo, you can increase the IQ appropriately, even if it will cause some noise (Ref. 1). For example, the information in the third document stated that the value of the spell was 3200. - ** Shutter Speed **: If the camera is fixed (such as using a tripod), you can use a longer shutter speed to get enough exposure, such as 20 seconds (Ref. 1). However, if it was hand-held, the shutter speed needed to be determined according to the anti-shake performance of the camera and the movement of the subject to avoid blurring the photo. A faster shutter speed such as 1/200 second (Ref. 3) might be used. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Sunset camera parameters
Here are some of the camera settings for shooting sunsets: ** 1. Exposing Mode ** 1. ** Aperture priority mode (Av or A)** - The aperture can be set between F8 - F16. In this mode, the camera automatically adjusted the shutter speed according to the set aperture, allowing better control of the depth of field and clear images of both near and far scenes. 2. ** Manual mode ** - Setting the parameters manually could allow them to respond to different scenarios more flexibly. ** 2. Light sensitivity (USB)** - Normally, it was set to between 100 - 400. If you wanted a more detailed picture with less noise, you could set it to 100 or lower. A low IQ would ensure the quality of the image in a well-lit sunset scene. ** 3. Metering Mode ** 1. ** Spot Metering ** - He changed the focus mode to center single-point focus and the light measurement mode to spot measurement. Then, he aimed at the clouds around the setting sun. Be careful not to focus on the building or the sun, or the image will be too bright or too dark. 2. ** Focus Average Metering ** - You can also set the measurement mode to focus on average measurement, which takes into account the key areas of the picture and the overall lighting situation. ** 4. Shutter Speed ** - If you use manual mode, the shutter speed can be set to 1/30 second or longer (depending on the shooting needs). ** 5. White Balance ** - You can choose the daylight white balance (or choose the appropriate color temperature value yourself, such as adjusting to the fluorescent light cool white can create a purple-pink romantic atmosphere, making the shooting scene more like the sunset atmosphere). ** 6. Shot ** - According to the shooting needs, you can choose 18 - 24mm or 100 - 400mm lenses. ** 7. Other Equipment and Points for Attention ** 1. ** Tripod ** - It's best to have a tripod to hold the camera, especially when using a slower shutter speed or taking long shots (such as time-lapse photography) to avoid blurring the picture due to camera shake. 2. **ND fade filter (option)** - If there was a ND filter, it could better balance the exposure difference between the sky and the ground. If not, try shooting the scene twice to mix the exposure. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>