When you really understand what is happening, you can exploit to the full all the means photography provides to express your artistic vision. Visualization is not really a question of technique. It is a method used to picture the finished photograph before it is taken, and is useful for everybody, regardless of whether they are using the zone system or not. Exposure control is key, partly because it is important to learn how your own photographic equipment works, and partly because you want to choose a shutter speed and aperture that will provide a negative with as much detail as possible. It is with exposure that we control the reproduction of shadows.
Contrast is controlled by development and the contrast grade of the paper used for printing.
It is the contrast control that determines how white the picture's light areas will become in the finished photograph. You should learn to use a suitable development time that will give you the contrast you are looking for. Difficult terms Visualization, exposure, and contrast control are terms that are simple to understand. However, we will save these for later and concentrate first on a few basic requirements. It is a common mistake to think that you only take one exposure each time you press the shutter button.