When you are in a level and you are searching for spirits, be on the look out for the unmistakable lens flare focus. You will know it when you see it - when you see effects on your screen that looks like a flare of some sort, you will notice that it is shaped like a crosshair. If you look in the center of the flare, you will see a spirit. These lens flares guide you to nearby spirits, so keep an eye out.