What is the formula for aperture, shutter speed and sensitivity?

The larger the aperture, the brighter it is, the slower the shutter, the brighter it is, and the higher the sensitivity, the brighter it is. The stronger the ambient light, the brighter it will be, and the greater the power of the flash, the brighter it will be. The closer the flash is, the brighter it is.

The aperture is represented by F. The smaller the number that follows, the larger the aperture (inverse ratio). Large apertures (such as f/1.4, f/1.8, f/2.8, etc.) allow for a large amount of light, making photos brighter in dark places. They can also be used with fast shutter speeds to "freeze" fast-moving objects (such as birds, airplanes, etc.) ,athlete).

With a small aperture and a slow shutter, you can shoot water, star trails, car tracks, etc., as well as light.

For shutter speed, the larger the denominator, the clearer the image. The movement trajectories of the small points in the denominator will connect into a line.

Sensitivity is represented by ISO. The smaller the number that follows, the lower the sensitivity, and vice versa (proportional). Pictures taken with low sensitivity are clear, while pictures taken with high sensitivity have a lot of noise.

Exposure value table

Extended information:

1. ISO sensitivity setting skills

1. Generally, there is sufficient light during the day ISO is 100 to 200.

2. Under dark conditions (such as rainy days), adjust the ISO to 300-400, relatively dark to 800, and the light is very dark (after the sun goes down), adjust to more than 1000 to shoot night scenes (such as Night celebrations and concerts) are adjusted to above 1,600.

Note: The higher the ISO is, the more noise will be in the photos taken, so the higher the ISO, the better. It is only used when the light is insufficient, and the ISO value should be lowered as much as possible.

2. Shutter speed setting skills

Shutter priority mode: Shutter priority TV for Canon and Pentax, S for Nikon.

Generally, it is the reciprocal of the focal length, and is set according to whether the scene is moving or not, and the speed.

1. Under normal circumstances, the normal shutter speed is between 1/60th of a second and 1/80th of a second.

2. When shooting pedestrians, moving objects on cloudy days or sunset, the shutter speed is 1/125 second.

3. To shoot high-speed moving objects or scenes, the shutter speed is 360/1 second~600/1 second, such as the scene of beating a basketball.

4. It takes 1/1000 of a second to photograph falling water droplets.

5. Use a slow shutter speed to take photos of satin-like flowing water or night scenes of car lights and rivers.

6. Use a fast shutter to freeze motion.

7. If the outdoor light conditions are good, the shutter speed can be faster, but if the light is dark, the shutter speed should be slower.

Note: The shutter speed is generally not commonly used. If you want to set it as the default shutter, then use A or automatic mode! Only these two gears are the default shutter speeds. Shutter speeds can be set in S and M settings.

3. Aperture setting skills

Turn the mode dial to A, AV or M (aperture priority or full manual)

Aperture priority (A , AV): The photographer first selects the aperture required for shooting, and then the camera determines the required shutter speed based on the lighting conditions on site.

The larger the aperture, the greater the amount of light that enters, the more obvious the background blur effect, and the more prominent the subject being photographed; the smaller the aperture, the smaller the amount of light that enters, and the greater the depth of field before and after the focus.

Generally speaking, macro photography often uses a larger aperture to achieve the purpose and effect of blurring the cluttered background.

In order to obtain clear and detailed images in front and back when shooting landscapes, a smaller aperture is often used for shooting. A large aperture is suitable for macro photography, while a small aperture is suitable for landscape photography.

Reference materials: Baidu Encyclopedia - Sensitivity

Baidu Encyclopedia - Aperture

Baidu Encyclopedia - Shutter