How to make the scenery as bright as possible in rainy and foggy days?

The best way is not to shoot, hehe, don't scold me.

One remedy is to buy a special filter, which I have only read in books and can improve the image quality in foggy conditions.

Demisting filter

Shooting in foggy days has another problem besides "Blue Square". That is, the distant image is "blurred". Similarly, filters can also help us solve this problem. Please look at the following two photos. Figure 7.5 was taken on a foggy summer day, and Figure 7.6 was also taken at the same time, but a Tiffen demister was used. As we can see, the details of the photo in Figure 7.6 are clearer. But you should know that demisters can't help us penetrate fog, even dense fog or mist. As shown in the figure, it can only help in moderate fog conditions.