How are the two exposures mentioned in photography done?

This was done in both exposures. Exposure is a shooting technique, which uses two or more exposures with different focal lengths to express the content that is difficult to express in a photo. Multiple exposure technology is generally used to take two or more photos. The multiple exposure function is the product of the film camera era. In traditional film SLR cameras, multiple exposure is a very important function and a unique photography technology. The principle of multiple exposure technology is to shoot multiple images on one film, so that an object can appear in the picture many times, and it can shoot magical effects out of nothing. This is its unique charm and attracts many people to use this technology.

First, simple multiple exposures

In the process of taking pictures, the camera and the object repeatedly exposed by changing the focal length remain motionless.

Take multiple exposure shots of the subject at different times or under different lighting conditions.

This can highlight the layering of the subject.

This is one of the most basic multiple exposure techniques, which is more suitable for shooting night scenes.

Second, change the focal length of multiple exposures.

For the shooting of flowers or still life, you can shoot two by changing the focal length.

One lens is in real focus and the other lens is in virtual focus.

In the process of real focus shooting, you can expose more, and in virtual focus shooting, you can expose less.

Thirdly, multiple exposures by occlusion method.

First, cover half the lens to shoot the subject once, then cover the other half lens to shoot the subject once at different positions, so that the subject can be exposed on the same negative through multiple exposures.

But when shooting with a digital camera, you don't have to block the lens, just take two pictures, and you need to keep the position of the lens still.

Fourthly, the superposition method is used for multiple exposures.

Preset positions in some areas of the picture and multiple exposures in reserved areas can also form a very expressive effect.

The position of the camera can be fixed or moved during shooting.

The method of fixing the camera position takes multiple photos of a person in multiple positions and then combines them together.