IPhone5s takes pictures. When you take ppt from a distance, it's all white. You can't see anything clearly, but others can read clearly.

When taking a photo, there will be an icon with a-/+symbol on the phone. Click on it and move the slider in the negative direction to darken the picture, so that you can clearly see the details in the picture.

This is called exposure compensation in photography, and the law can be summarized as "white plus black MINUS", that is, increasing exposure when shooting high-brightness pictures and reducing exposure when shooting dark pictures. The principle is as follows: 1. When the whole picture is bright (white), the camera will automatically reduce the brightness of the picture because of overexposure, resulting in underexposure, and the white will become light gray; 2. When the whole picture is dark (black), the camera will think that it is underexposed, so it will automatically increase the brightness of the picture, resulting in overexposure, and the black part will become gray and the bright part will become all white. This is the case when shooting PPT in the distance. It should be that the surrounding environment is dark.