One of the biggest problems with photographs, is that we, as investigators, take most at night, low-light and flash-usage conditions.  Photographs taken in these conditions lend themselves to be "grainy" or pixelated.  When someone looks at these types of photos, it is very easy to see something in the picture that simply doesn't exist.  This is due to something called "pareidolia" - when your brain works to make sense of nonsense which is a natural function of our brain.  The brain tends to "choose" to see something that makes sense to it.  Some also call this "matrixing".  This is what's happening when people see familiar faces in their burnt toast or in condensation on a window, etc.  See the photo below?  We all know this is not some sort of apparition, but I'll bet you also see the face of a man made from the leaves' shadows.  This is another reason you won't see a lot of photographs as possible data from us.