 great black and white photographs are a rich range of tones. When you look at the work of Ansel Adams you can see this in action that it's not just contrasty punchy images or images that are smooth tones. They have a variety to them that they use these ideas when they are needed. To know at the end where you want to be is so important with black and white photography because the steps that you take when you have the camera in your hand are setting you up for success here in the dark room and it's your job to think about black and white photography, to visualize the image, how the scene will look in black and white. If you don't know what the end product is going to look like then it makes the beginning so much harder. You can't just go around snapping whatever you want in the off chance that it's going to look kind of cool black and white.