A great photo happens when

A great photo happens when a photographer sees a situation unfolding in front of them that evokes an emotion that the photographer feels deep down, in the middle of their chest. And in a split second, they then make a conscious choice of exposure, lens, depth of field, lighting, body language, composition, etc., and release the shutter. The film is then processed, scanned, laid out on a page, printed on a press, driven across town to the newspaper carrier who throws it on some guy's porch, who then opens the newspaper and looks down at that photo… and if that guy gets the same feeling deep down in the middle of his chest that the photographer did when they viewed the situation in the first place, they have made a great photo.