As the title states, I was cleaning the mirror and viewfinder inside my camera and might have wrecked it. I have a Cannon Rebel XTi . I removed the lens and cleaned the first mirror you see, then cleaned the mirror that it above that, that I am told it the "viewfinder". I cleaned this with a lint-free cloth and isopropal alcohol. The problem now is that when I look thru the view finder to take a picture, I have a residue that looks like a stain. I have since cleaned it with "Cannon" brand lens cleaner and lens tissue but the "residue" will not go away. I camera is still taking quality pictures, but this is not right and is annoying.