What's the difference between changing the aperture by photography and changing the aperture?

In the previous manual lens, the aperture was changed by manually rotating the aperture ring. For example, photography needs an aperture of F8, but at this time, the light may be bad, and the viewfinder may not see clearly under such a small aperture of F8, so adjust the aperture to the maximum when focusing on the composition, and then adjust it to F8 after focusing on the composition. Now the digital camera doesn't have to be the same as before. Now the automatic lens automatically focuses and composes automatically. This is the process of aperture change during photography.

Reply to your supplement:

1: If conditions permit, increasing the brightness of light source is the best scheme.

2. Increasing the aperture will affect two points: 1 more light; 2. The depth of field becomes shallow, and the background is easily blurred (incomplete, and the degree of blur depends on the focal length and background distance).

3. Slowing down the shutter will affect two points. 1 large amount of light. 2. If the hand-held jitter factor is ignored, the shutter speed is basically the same when the subject is still, but if the subject moves more or less, the shutter speed is higher than the shutter speed, such as shooting water. If the shutter speed is fast, you will see some small water droplets like water droplets. If it is slow, you will see it as smooth and fuzzy as milk. In addition, the slow shutter has a great influence on the hand grip, because the hand will shake. )

4 sensitivity, because the higher the sensitivity, the more prone to noise in photos, so in principle, the lower the sensitivity, the better, and only raise it when there is no way.

Summary:

1 the light source is easy to understand, so I won't say it.

Sensitivity is easy to understand, that is, the lower the better.

Residual shutter and aperture

In terms of entering light, the shutter and aperture have the same influence on entering light, but the difference is that the aperture will affect the depth of field and the shutter will affect the effect of moving objects, so the camera will have two modes: shutter priority and aperture priority, depending on whether you need depth of field or motion effect.