What exposure must a novice photographer learn?

Lead: If a photo can't even be seen and recognized, it is impossible to further discuss beauty and value. "Exposure" is used to explain whether a photo can be seen or not, and it is also the basic technology of taking pictures.

What is "exposure"?

Simply put, exposure means that the film/photosensitive element in the camera receives external light and then forms a picture.

If the camera receives insufficient light and the photo is too dark, we call it "underexposure". If there is too much light and the photo is too bright, it is called "overexposure", and if the image can be properly presented in the photo, it is called "correct exposure".

There are three different exposure conditions:

Exposure settings on the camera

Underexposed, too dark

Ok, the exposure is correct.

Overexposed, too bright!

Cognitive exposure triangle

The exposure setting directly determines the brightness of the photo. This setting is determined by three conditions: aperture size, shutter speed and sensitivity (ISO), which are collectively called "exposure triangle", and these three settings will affect the depth of field, dynamic blur and noise besides the amount of light entering.

hole

Controls the amount of light entering the lens.

The larger the aperture, the more light enters.

shutter

Control exposure time

The longer the shutter is open, the more light will enter.

ISO sensitivity

Controls the sensitivity of the camera to light.

The higher the ISO, the more sensitive the camera is to light.

In other chapters, we will tell you in detail how the above three exposure settings affect a photo and what kind of shooting effect can be created. ? www.fsbus.com

Cognitive histogram

After learning what is the correct exposure, you will judge for yourself on the LCD screen of the camera after taking pictures, right? But sometimes, for example, when shooting in the sun, you may not be able to see clearly whether the photos on the LCD are bright or dark. The human eye is always unreliable. When you go home and look at the photos, it's too late to find them too dark. At this time, you can use the objective histogram to analyze them.

Histogram is a common tool for analyzing photo exposure. In the preview mode of digital photos, there is usually a page that shows you the histogram.

In the histogram, the camera will arrange each pixel of a photo from light to dark, with pure black on the far left and pure white on the far right, so the histogram is to show how much each gray level in the photo accounts for.

The rocks in the above picture are dark, so the histogram distribution should be to the left under correct exposure.

On the contrary, because the cherry blossoms in the above picture are light, the main distribution should be to the right.

As can be seen from the above two examples, histogram is actually a tool to reflect the light and dark distribution of photos, so people should judge whether the light and dark distribution is appropriate according to the content of the picture, and then adjust the camera settings.

Understand the exposure meter.

Modern cameras usually have a built-in exposure meter. When the symbol points to 0, this is the camera's suggested exposure value. If it is on the+side, it is lighter than suggested. Over there, it's darker than expected. The camera's suggestions will change according to different metering modes, which will be explained in other chapters later.

In addition, the camera's advice does not mean proper exposure, and we still need to adjust the camera according to personal requirements as mentioned above.

The so-called "correct exposure" is to keep the most information in the picture, but whether it is beautiful or not is two different things. It is more important to use the tools at hand to shoot the desired effect.