When shooting in a studio one of the frequent demands is to create a perfect white background or a perfect black background images. Whilst small variations can be corrected using software such as photoshop this will frequently change the subject as well. Also fine detail such as hair might be lost. It is always best to try to light your subjects as close as possible to the final image and not rely on photoshop. You will however require a flash meter to get the settings right, otherwise there will be a large amount of trial and error.