I'm not an expert in photography, but as a record producer, songwriter and music arranger, "previsualization" does exist. Not always, but not never either.
When I'm developing a melody, sometimes I previsualize what other instruments will be there;
When I'm playing the piano part of a song, sometimes I HAVE TO previsualize what the orchestra will be playing so we are supporting each other instead of stepping on each other's toes.
Etc..
Yet sometimes an idea just popped up and I just wrote it down, and if I got a guitar or a piano beside me I'll just develop it right there right then. Even under this kind of situation, I can still previsualize what it will become, with my experience of music producing, and memories of well-written or well-arranged songs by the others. But I can still choose to NOT previsualize and let the Muse guide me.
The precious thing about previsualization, IMHO, is that if you're very well self-trained with it, and are able to do it in a flash, it really helps a lot when you need it. Then again, it doesn't mean that we have to use it all the time.
And the most important of all, when you do, and you make it in the end, it's the most exciting thing in the world.
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I like this article. Helping me or not, the author made it very clear that this was HIS opinion and not everyone has to follow it. I don't like articles that seem to be shouting "if you don't agree with me you must be an idiot", but this one is not one of them. Therefore I don't see anything bad about it.
My 0.02.