The best way is for you to get the help of your local doctor and have them tell you which pictures contain information about the disease and, if possible, have them help take the film on a reading light. The next point is to ask and mark them at your local clinic before you take them yourself. Take the picture with a little skill, with lighting from the back of the film, preferably a reading light, or you can take the picture with the film taped to a bright window and not with a flash. When you take a picture, take a general one first, and then take the part containing the lesion, preferably one in 4 to 6 frames. Simply put, seven words: black and white, macro, no flash.