But you frame a picture for the best composition at the time you shoot it. You don't need to previsualize anything. It's right there before you in the viewfinder. I seem to get the feeling that this is being hyped as to something mystical. Sort of like the black arts of a secret society.
For example, you aim the camera and there's a telephone pole sticking out of your subject's head. Well, I don't have to previsualize anything. It's right there and wrong. So I move over so the pole shifts. What am I previsualizing? Then I wait for the sun to start setting so the picture and the subject warms up, again in my viewfinder. What am I previsualizing there? IF you don't see and get it at the time of the shot, you don't;t get it. Well, unless you do a lot of photoshopping like cloning skies or darkroom magic which is a separate discussion.
I don't pre-visualize, unless I am in a Minor White* frame of mind.
I have a couple of friends who greatly frustrate me, because their photographs never leave their phones or, in one case, their cameras. In that latter case, when they filled up the memory on their compact digital camera, they bought another camera!
But anyone who presents their photographs to others in a manner other than on the little screen on the phone or the back of the camera, usually at some step of the process thinks about how the photograph of the scene (not the scene itself) will look - that is what visualization is.
When you look through the viewfinder of your camera and note the telephone pole behind your subject, it doesn't bother you in real life, because you have enough three dimensional information to be able to easily differentiate between foreground and background. If you were using a stereo camera, you might elect to do nothing, because much of that three dimensional information is retained in a stereo pair of photographs. But because you know that a single two dimensional photograph looks funny with a telephone pole coming out of the subjects head - because you can visualize how poor that will make the photograph look - you adjust your position, and eliminate the problem.
When Ansel Adams and Minor White and others started all of the famous discussion about visualization (*Minor White preferred pre-visualization) they were responding to a couple of factors.
One of those factors related to the struggle to have photography accepted as an art form - something much more than snapshots. Just like a painter who visualizes a result before any paint is applied to a canvas, they were showing that photographers do the same.
The other factor related to the more technical aspects of the Zone System - the applied sensitometry, the placement of exposure values and the use of development controls to match the negative to the contrast of the paper. Those techniques were (and for some still are) useful when trying to make what one one visualizes come true (on a print).
Some photographers prefer photographs that are quite natural and life-like and apparently un-manipulated. I expect Alan fits within that group. Others prefer photographs that are very different than "natural". But both types of photographers form a picture in their mind of what the final result will look like at various stages in the process. Adams
et al advocated that the process of visualization should happen at or before the time of exposure.
