What should I consider when choosing an aperture?

In daily shooting, aperture priority (Av file) is undoubtedly the most commonly used shooting mode.

In this mode, we must manually set an aperture value, and then adjust other shooting parameters for exposure control. Then the question is coming, how to choose the aperture value?

What are the different picture effects of large aperture, small aperture and medium aperture? What are the precautions when using these aperture values?

Different aperture values bring different effects and are suitable for different themes.

Don't worry, I'll explain it to you slowly ~

Advantages and applications of large aperture.

With a large aperture below f/4, the depth of field is very shallow, and the clear range outside the focal plane is very small, so it is easy to shoot the effect that the subject is blurred and the background is clear, effectively separating the subject from the background.

As shown below, under large aperture, other flowers near the main body are blurred, effectively highlighting the main body.

The common application of large aperture in daily life is beauty portrait and still life.

The most troublesome thing about taking portraits is the choice of background. The background is too messy, there are too many eye-catching still lives, which is a headache, and as long as the aperture is turned up, these problems will be solved.

Everything will become colorful pieces, and only the subject's face will be clear. ......

It looks beautiful, but it seems to lack some unforgettable connotations. This kind of photo with mushy background, beautiful subject and beautiful appearance is called sugar water photo.

It's a good thing to shoot sugar water, but it's not a good thing to just shoot sugar water or just be satisfied with shooting sugar water? This is your enemy to improve your photography skills!

In addition to portraits, still life photography, including merchandise display, plants, flowers and even food photography, can use large aperture to achieve the effect of highlighting the main body.

In street shooting and tourism photography, because the background is often messy, use a large aperture? King James? The main body of your picture is also very common, even the only way.

The shallow depth of field caused by the large aperture only makes the subject clear and blurs other scenery, so the audience can easily see which is the subject and what theme you want to express.

As shown below, the big aperture clearly tells the audience:? I shot the couple in the lower right corner, not the tourists and the giant Ferris wheel? .

In short, the biggest function of large aperture is to highlight the subject, blur the background and create a sense of hierarchy.

The reader said,? Is the aperture good? What are the disadvantages? ?

There are sun and moon in the sky, yin and yang in the ground, everything has good and bad sides, and the big aperture is no exception. Next, I will talk about some common problems of large aperture in practical application.

2. The problem of large aperture

The shallow depth of field made of large aperture will bring a serious problem, that is? Sometimes the scenery is too deep.

What do you mean? The scenery is too deep? ? A picture explains everything!

As shown below, the depth of field is too shallow, so that half of the face is blurred? If the photo was taken by this girl's boyfriend, it is estimated that it will be cleaned up!

This example is a bit extreme. Few people are so careless that half their faces are burned and they don't know it. But even if the whole subject is in a clear range, another problem still exists.

That is, the aperture is too large, which will reduce the sharpness of the subject, that is, the clarity and detail expression are insufficient.

It may be a little hard to understand just using words, but it's still the same. For example.

The stone lion on the left of the picture below is obviously the main body of the picture, and the whole picture is in a clear range. There seems to be no big problem:

But! Yes! Although it seems that the whole subject is quite clear, in fact, the clarity of each part is still different.

In the red circle below, the face of the stone lion is the focus and the clearest;

The blue circle in the picture below, the curled part of the lion with a certain distance from the face plane, looks very clear, but if you zoom in and look carefully, you will find many details missing.

This is a significant problem in large aperture shooting: the subject is not sharp enough to take care of all the details of the subject.

Of course, some people think that this is not a problem, but a kind of welfare that is worth using. For example, this talented guy uses a big aperture to dilute the acne on his girlfriend's face.