How to adjust the aperture of SLR camera

How to adjust the aperture of a SLR camera, let's talk about the relevant knowledge.

1. What is an aperture?

The size of the aperture will affect the amount of light entering and the depth of field. The smaller the f value of the aperture, the larger the aperture. Under the same ISO and shutter conditions, the larger the aperture, the brighter the picture will be. The relationship between aperture and depth of field: F2.8 large aperture is easy to cause shallow depth of field with blurred background; With the small aperture of F 16, the subject and background will be clearer.

Take notes:

The aperture will be represented by "f/xxx", such as f/8;

Small number = large aperture. For example, f/ 1.4 is a large aperture and f/22 is a small aperture. Don't make mistakes.

Therefore, it is generally recommended to buy a lens with a "large aperture", which not only makes it easier to take shallow depth-of-field photos with blurred background, but also improves the success rate of shooting stable images indoors and in dark scenes.

2. What is a shutter?

Shutter speed represents the length of exposure time. Usually, in the case of sufficient light, the shorter the exposure time, and in the case of insufficient light, the longer the exposure time. Usually, a tripod is needed to stabilize the camera for a long time exposure, so that the image will not produce shake afterimage.

Door B controls the opening time of the blinds by itself. When the shutter button is pressed, the shutter will open until the shutter button is released (using shutter B with cable release can avoid camera shaking when the shutter button is pressed).

Take notes:

High-speed shutter has less light, while slow shutter has more light.

High-speed shutters often see 1/xxx seconds, such as 1/250s,1/4000s;

Generally, the fastest camera can be set to 1/4000s or 1/8000s, and the slowest camera is usually 30s.

Shutters over 30 seconds can be replaced by B/ bulb shutters.

3. What is sensitivity?

The higher the sensitivity value, the more light is received. Under the same aperture and shutter conditions, the picture will be brighter with the increase of sensitivity. The noise (graininess) of the opposite picture will also increase.

Take notes:

The higher the ISO, the more light can be absorbed in the dark environment, and the photos become brighter.

The higher the ISO, the more obvious the noise and the worse the photo quality.

Formula: The bigger the aperture, the brighter it is; The slower the shutter, the brighter it is; The higher the sensitivity, the brighter.

So how should I set it up in actual shooting?

Brother Wen suggested that the first step is to choose the shooting mode. If you choose automatic shooting mode, then these three parameters don't have to worry. However, we should know that all the masters shoot with the M manual gear, so let's take the manual gear as an example.

Parameter setting steps:

1. First select the shooting mode-M manual gear;

2. Sensitivity setting: according to the shooting environment and whether the light is sufficient, such as day or night, if the light is insufficient at night, the sensitivity value should be set to a larger value, such as1600,3200; If it is daytime and the light is sufficient, the sensitivity can be set to 100-300, and the lowest setting is selected to ensure the photo quality.

3. Aperture setting: In a well-lit environment, you can set a smaller aperture, but it is not the smallest, and you can adjust it between f/8- 1 1. Generally, f/8 is the golden aperture value chosen by many photographers; If the light is dim, you can adjust the aperture and debug it in f/2.8-4. If you want to shoot a blurred background with a shallow depth of field, such as a portrait, you can enlarge the aperture and debug it in f/2.8-4. ; If shooting scenery, it is suggested to narrow the aperture and adjust it between f/8- 1 1.