How to take a photo twice?

This is called multiple exposure. Multiple exposure is a shooting technique, but in order to set off the atmosphere, this technique is often chosen, and two or more exposures with different focal lengths are used to express the content that is difficult to express in a photo. Multiple exposure technology is generally used to take two or more photos. It can be said that 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 are kept still, and multiple exposures to the object at different times or under different lighting conditions can highlight the layering of the object. 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 take two shots by changing the focal length, one is real focus and the other is virtual focus. As shown in figure 2, the two photos are the effects of real focus and virtual focus shooting respectively. 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.

The so-called blocking method is to block half the lens to shoot the subject once, and then block the other half lens to shoot the subject once in different positions, so that the subject can expose a negative at the same time. But when you shoot with a digital camera, you don't have to block the lens, just take two pictures. It should be noted that the position of the lens needs to remain fixed.

Fourthly, the superposition method is used for multiple exposures.

Another method is to set aside a position in some areas of the picture in advance, and multiple exposures in the reserved areas can also form a very expressive effect. During shooting, the position of the camera can be fixed or moved. Here, we use a fixed camera position to take multiple photos of a person in multiple positions and then synthesize them together.

In the era of digital cameras, due to technical reasons and the convenience of digital post-synthesis, the multi-exposure function has been gradually ignored by manufacturers. Even professional digital SLR cameras have no multiple exposure function. Although multiple exposure is rarely used in daily shooting, it is really effective in some special occasions, such as fireworks shooting and night shooting. Digital camera has powerful post-processing advantages that traditional cameras can't match. It is easy to achieve multiple exposures when multiple photos are superimposed and fused in Photoshop, that is, two or more films with the same background are placed in the same picture in a multi-layer way, and then the "Brightening" mode is selected when the layers are fused, so that the effect of multiple exposures can be achieved.

And now the SLR is basically ok.

D90 will definitely do. Even if I use the d90, the D90 also supports high-definition camera shooting ~ I just can't autofocus without camera shooting ~ Personally, I think this function is a bit lame.