How to understand the exposure curve and skillfully use exposure or flash compensation

Lead: "Your photos are overexposed! Is it difficult to correctly judge whether the photo exposure is appropriate every time you take a photo? How to choose the application of exposure compensation and flash compensation in camera? Listen to how the photographer Shenlong Photography understands the exposure curve and skillfully uses exposure or flash compensation to shoot good works! How to understand the exposure pattern and skillfully analyze the exposure situation with exposure or flash compensation?

These three photos are underexposed, normal and overexposed. From the picture, there is overflow on the right side of underexposed photos, overflow on the left side of overexposed photos, and the normal exposed photos are evenly distributed. From the picture, we can see which one is excessive and which one is insufficient. Moreover, the dark parts of underexposed photos are too dark, and the skin color of the characters is dim; The background of overexposed photos is too bright and the characters have no details; The photos exposed normally have rich details, high color saturation and strong stereoscopic impression. So it's a good habit to look at the graphics at any time when shooting.

▲ Normal exposure

▲ Underexposure

▲ overexposure

Exposure compensation and flash compensation

Exposure compensation

Exposure compensation, also called EV (exposure value) adjustment. With this function, you can adjust the automatic exposure set by the camera up or down by several levels. A value of 0 indicates the exposure recommended by the camera. Selecting+values (such as +0.3 and +0.7) can increase the exposure and make the image brighter; Selecting a value (for example, -0.3, -0.7) can reduce the exposure and darken the image.

When the shooting environment is dark and it is necessary to increase the brightness, and the flash can't work, exposure compensation can be carried out to increase the exposure appropriately. When making exposure compensation, if the photo is too dark, the EV value should be increased. Every time the EV value increases, it is 1.0, which is equivalent to doubling the absorbed light. On the other hand, if the photo is too bright, the EV value should be reduced. Every time the EV value is reduced, it is 1.0, which is equivalent to reducing the light input by half.

▲ Exposure compensation EV-0.7

▲ Exposure compensation EV0. 0

▲ exposure compensation EV+0.7

▲ exposure compensation+1EV

Flash compensation

The purpose of flash compensation is similar to exposure compensation, allowing users to adjust the intensity of flash output through flash. Flash compensation can change the exposure ratio of the surrounding environment and flash. When the camera's flash measurement system can't accurately output the flash according to the shooting environment, resulting in overexposure or underexposure, flash compensation can achieve a good correction effect.

For example, if you want to blur the background and highlight the subject, you must choose a large aperture. In order to fill people's face with light, the flash must be turned on. The minimum shutter synchronization speed of the camera is generally1125 s. In this case, the photos taken may be overexposed. At this time, reducing the flash compensation can solve this problem.

▲ Flash compensation-1

▲ Flash compensation is normal.

▲ Flash compensation+1

▲ Canon 450D flash exposure compensation function.