The best shooting distance of the lensThe best shooting distance of the lens was affected by many factors, and it was difficult to give a fixed value.
In terms of focal length, lenses with different focal lengths had different characteristics. For example, in portrait photography, the distance from the whole body to the close-up shot with an 85mm focal length was about 1.5 to 5 meters. The 35mm-85mm focal length commonly used for portraits was not only close to the human eye, but also the shooting distance.
The closest focusing distance of different lenses refers to the straight-line distance from the focal plane of the object to the focal plane of the image. The closest focusing distance of different lenses is different. Generally, the longer the focal length of the lens, the longer the closest focusing distance; the shorter the focal length of the lens, the shorter the closest focusing distance. However, this rule does not apply to macro lenses. The closest focusing distance is usually marked on the lens. There was no maximum focusing distance. The " infinity " on the lens indicated infinite focusing.
When the focal length of the lens did not change, the shooting distance determined the size of the scene. It could be divided into long-range, panoramic, mid-range, close-up, and close-up. Close-up shooting was close, the subject was large, and the scope of the scene was small; long-distance shooting was far, the subject was small, and the scope of the scene was large.
In surveillance cameras, the focal distance of a 2.1mm lens was 3 meters, and the focal distance of a 25mm lens was 80 meters. The larger the lens, the farther it looked, but the smaller the angle. Its effective range changed according to the size of the lens, generally within 100 meters, and its range was also variable when the lens was variable. The magnifying factor of the lens was approximately equal to the ratio of focal length to object distance. As the focal length increased, the magnifying factor increased, allowing the close-up view to be zoomed out and the details in the distant view to be clearer.
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Reaction distance, brake distanceReaction distance refers to the distance the vehicle traveled within the driver's reaction time, including the brake reaction time (from the discovery of the stimulus to the movement of the foot to the brake pedal), the brake action time (from the start of the brake pedal to the maximum braking force), and the continuous braking time (from the maximum braking force to the car stopping).
Braking distance referred to the distance traveled by a vehicle from the beginning of braking to the complete standstill of the vehicle when the vehicle was moving at a certain speed. It was the distance traveled by the vehicle from the moment the driver stepped on the brake pedal to the moment the vehicle came to a complete stop at a certain initial speed. It included reaction distance and braking distance. The smaller the braking distance, the better the braking performance of the car.
The length of the reaction distance depended on the driving speed and reaction time. The higher the driving speed or the longer the reaction time, the longer the reaction distance. The reaction time was directly related to the driver's sensitivity and technical proficiency. Usually, the reaction time was 0.75 to 1 second. For example, when the driving speed was 30 km/h and the reaction time was 1 second, the reaction distance was 8.33 meters.
The length of the braking distance was related to the driving speed, the braking force, and the friction coefficient. The higher the driving speed, the longer the braking distance. The driving speed was proportional to the square of the braking distance. The calculation method (commonly used internationally) was: Braking distance = vehicle speed/10 * 3+ vehicle speed/10 * vehicle speed/10, but there would be differences if the tires were different (such as summer tires and winter tires) or the road conditions were different.
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Safety distance, braking distance, reaction distance, subject oneIn subject one, stopping sight distance included reaction distance, stopping distance, and safety distance. Reaction distance refers to the distance that the car travels from the moment the driver finds an obstacle in front of him and decides to take braking measures to the moment the brakes really start to work. Braking distance refers to the distance from the moment the brakes take effect to the moment the car comes to a complete stop. The safe distance (in the concept of stopping sight distance) was the minimum safe distance that should be maintained between a car and an obstacle after it had completely stopped.
For example, in some scenarios, the safety distance was stipulated: on the highway, when the speed was lower than 100 km/h, a safety distance of more than 50 meters should be maintained from the car in front; when the speed was higher than 100 km/h, a safety distance of more than 100 meters should be maintained from the car in front; when the speed was equal to 100 km/h, the minimum horizontal distance was 1.5 meters, the safety distance was 100 meters, and the dangerous distance was 50 meters. Also, in low visibility weather conditions, when the visibility is less than 200 meters, the speed should not exceed 60 km/h, and the distance between the car in front of the same lane should be at least 100 meters; when the visibility is less than 50 meters, it should leave the highway.
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In the distanceThe cast list in Distance included Liu Ye, Ma Yili, Mei Ting, Bao Jianfeng, Zeng Li, Zheng Qi, and Xue Haowen.
In the DistanceIn the Distance was an urban start-up drama directed by Chen Kunhui and starred by Liu Ye and Ma Yili. The drama mainly told the story of Yao Yuan in the express delivery and Internet start-up waves. Yao Yuan was a low-level courier. After he was intercepted by the law enforcement of the post office, he set up a trap to get to know the daughter of the head of the state-run post office, Lu Xiaoou. He started a series of exchanges with her in exchange for information. The plot also depicted Yao Yuan's perseverance and ups and downs in his life. You need to watch the series for more details.
What is the difference between the braking distance, the reaction distance, and the safety distance?Braking distance refers to the distance traveled by the vehicle when the vehicle is at a certain speed. It is one of the key parameters to measure the braking performance of the vehicle, including the reaction distance and the braking distance.
The reaction distance referred to the distance the vehicle traveled within the driver's reaction time. The reaction time here included the brake reaction time (from the discovery of the stimulus to the movement of the foot to the brake pedal), the brake action time (from the start of the brake pedal to the maximum braking force), and the continuous braking time (from the maximum braking force to the car stopping).
The safe distance refers to the necessary distance between the rear vehicle and the front vehicle to avoid accidental collisions. Its accurate measurement depends on the braking distance, but it also takes into account the driver's reaction time. Different driving speeds, weather conditions, types of vehicles, and road conditions had different requirements for the safe distance.
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What are some of the best long - distance love novels?Well, 'The Time Traveler's Wife' by Audrey Niffenegger is a wonderful long - distance love story. Henry has a genetic disorder that causes him to time - travel involuntarily, which often takes him away from his wife Clare. It's a very unique take on long - distance love as the distance is not just physical but also through time. Also, 'Me Before You' by Jojo Moyes has some aspects of long - distance love. Louisa and Will come from different worlds and Will's decision to end his life in a way separates them in a very difficult way.
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2024-12-06 07:22
What are the elements that make the best long distance stories?Communication is key. In the best long - distance stories, people find ways to communicate effectively, whether it's through letters, emails, or calls. Hope also plays a role. The military couple hoped to be together someday and that hope kept them going. And of course, sacrifice. The person who moves away for work in a long - distance friendship often sacrifices being close to their friend, but they make it work because of the value of their relationship.
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2024-11-30 13:49