How to adjust the manual exposure of the camera

This article is a column chapter of photography encyclopedia, and friends who like it can click to subscribe. Thank you for your attention.

Manual exposure mode is the most accurate exposure mode. For beginners, this mode is more difficult than aperture priority and shutter priority. This paper interprets manual exposure and understands manual exposure (M-block) from another angle.

Manual exposure mode

Manual exposure

-The photographer decides the shutter, aperture and sensitivity.

-After changing the angle, the exposure remains unchanged.

-Depth of field, shutter effect and noise determine parameters.

In the last article, we learned that in aperture priority mode and shutter priority mode, the camera will automatically calculate the exposure parameters needed for the scene only by setting the aperture size or shutter speed respectively. In manual exposure mode, the aperture, shutter and sensitivity are all adjusted manually (except automatic sensitivity).

M-block and exposure compensation

Before understanding the manual mode, recall the knowledge of exposure compensation function.

The exposure compensation function can change the light and shade effect of the image in automatic mode and semi-automatic mode, and its principle is to change one of the parameters of the shutter or aperture. However, in manual mode, the exposure compensation function fails, and the only useful one is the exposure compensation table, which does not directly affect the exposure results, but can be used as a reference for the exposure table in manual exposure mode. Understand the camera: What is "exposure compensation"? What does it do and what effect does it have on the photos?

When the exposure is insufficient, the arrow or white point below the exposure meter will move to a negative number (-);

When overexposed, the arrow or white point below the exposure meter will shift to the positive (+) direction;

When the exposure is normal, the arrow below the exposure meter will appear in the position of 0. Normal metering does not mean normal exposure, and sometimes it needs to be left or one side to ensure rich details of highlights and dark parts of the picture.

Beginners practice with fixed sensitivity.

For beginners, manual exposure will encounter many problems at first, so it is recommended to use fixed sensitivity. Depending on the shooting situation, overexposure will reduce the sensitivity, otherwise underexposure will increase the sensitivity. In order to ensure the details of the picture, the parameters between ISO 400 and ISO 800 can be used in the early stage, and can be relaxed to 800- 1600 at night.

The advantage of this is that you can learn to manually adjust the three parameters step by step, and there is a familiar process.

Manual exposure (m)

Let's first review the influence of the three elements of exposure on the photo effect.

Aperture: the larger the aperture, the more light enters and the shorter the depth of field; The smaller the aperture, the less light entering and the longer the depth of field.

Shutter: The faster the speed, the less light enters, freezing the subject; The slower the speed, the more light enters, and the dynamic blur.

ISO: low value, fine imaging; The numerical value is high, and the image has particles, but it can brighten the picture.

These three parameters directly affect the exposure effect, but the more critical "safety shutter" should also be considered.

Column chapter: knowing the camera: what is the shutter? What is a safety shutter? Look at the shutter effect.

Aperture priority only needs to control the depth of field of the aperture and leave the rest to the camera; Shutter priority only needs to control the dynamic and static effects of shutter speed. If the safety shutter is not considered in these two modes, it is easy to blur the image without hand-held anti-shake.

The difficulty of M-block lies in parameter combination. Different combinations have different effects, but they are all based on aperture priority and shutter priority, more like the combination of aperture priority and shutter priority.

When using M file, we should consider the change of depth of field, dynamic and static effect and safety shutter.

Assumption: Take a photo of a flower with a shallow depth of field and normal exposure in an environment with sufficient light and small light ratio.

The hardware device is a full-frame camera with a 50mm fixed-focus lens. The exposure parameters are11250, ISO3200 and F 1.8.

If this picture is exposed normally, it is not a high-quality picture in terms of parameters, and the noise in the picture is obvious.

The reason for this is the following：

In a well-lit environment, shooting static flowers at the shutter speed of11250 is theoretically allowed, but the speed is too fast. According to the concept of safety shutter, you can shoot a static subject at any shutter speed between1/60-11250, that is,

The aperture is F 1.8, which highlights the main body and reduces the influence of messy background. This parameter can be reduced or increased appropriately.