Photography is a medium that condenses an event into an instant. Choosing which instant to capture has a great deal to do with the message that the image will convey. In the psychology of photography, anticipation usually has more power than result. Take a batter at the plate as an example. If you snap the picture just before the ball reaches the batter, you preserve all the outcomes of the event. The batter may strike out, hit a home run, or something in between. All of those possibilities remain in the final image. Capturing the ball just as it passes the batter excludes everything but a strike.
Even though you take the picture with a certain image in mind, it’s the imagination of the viewer that you are trying to touch. Taking pictures is about putting your vision of the event on record, but it’s in the viewer’s imagination that the image takes on significance. The best pictures leave several interpretations open, so the viewer can take something from it without feeling forced or cajoled. It’s not important that the viewer see what you saw, just that something in the picture touches a memory or feeling in the viewer. A picture of a kiss has more power if there is a tiny bit of space between their lips, not when they are locked together. It also preserves the anticipation in your subjects to take the picture just before. If you watch two people kiss, their body language changes in subtle ways after their lips meet. There is a tension in their stance as they approach each other that becomes relaxed after their lips meet. It’s not something that you could consciously pick out of a still image, but it’s something that we all recognize subconsciously from our past experiences. Tension is a driving force in photography. It’s the distance between imagination and result that drives the image and makes it important to the viewer.
All photographic rules are relative, though, and meant to be broken. Presenting a result to the viewer can sometimes be just as powerful as an anticipatory picture in some cases. In that case, the subject, not the artistic composition, provides the meaning of the picture. If the subject is compelling enough, you don’t even have to get the settings right to get a good picture. Most journalistic pictures are result driven, showing the aftermath of an event rather than conveying anticipation. Those pictures rely on the internal image of “before” that the viewer has in their mind when you present them with the “after”.
The hardest part of photography is in the mind of the photographer. The image in your mind that you’re trying to capture isn’t necessarily the image that the viewer will take away after viewing it. As a photographer, you have to accept that, and not try to impose your vision on the viewer. That means leaving as many possibilities in your images as possible, so that each viewer can take something from it. It’s easy to understand the artistic impulse to portray a powerful image with no equivocation and no room for interpretation. It’s your vision, after all. The power of an image is in the sharing, though, so it’s usually best to leave some wiggle room for the viewer.