Oddly, I have never explored this question in depth until I recently read an interview with Robert Polidori in
American Photo. (Outstanding publication by the way - go subscribe if you can)
Partly, it's because of the way I model the photographic process in my own mind. What the brain perceives and what the camera records are two very different things. It's the reason why holiday snapshots are often accompanied by the "this doesn't do it justice" commentary. It's why we spend hours in post-pro when a 1 degree shift to the right in real-time would have solved the problem in a heartbeat.
I've always felt that photographers should work out why a particular scene is so special "live" and then do our best to recreate this with the images we create. We succeed when our image conveys at least some of the zeitgeist and gestalt that we felt when surveying the scene in person. So to answer the original question I would implicitly have said or perhaps assumed that the image should strive to be as good as the real thing but not better.
Robert Polidori's words have forced me to examine that instinctive assumption and ultimately to subvert it. Robert's answer to this question is that the photo should be better than the thing itself. Otherwise why bother taking the photograph? This is a supreme challenge. It forces us to go beyond the real and improve it in a way that matters. It goes without saying that this is no easy challenge. It may even be impossible.
I can't help but think of U2's "Even better than the real thing" riff as I reflect on this though. In fact this song title was written to reflect the emerging need for instant gratification in the 90's. Does this mean that what I could call "elevated" photography has the same effect and is contributing to a lack of focus? Will it diminish that live experience?
Perhaps, but on the other-hand, a glorious, exaggerated rendering of a subject can only serve to honour it. It's why we were attracted to take the photograph in the first place.
This manual pan I took of the Milky Way in the Atacama desert is nothing like what you can see with the naked eye. The long exposure reveals an inner beauty which is unavailable to our native view and perhaps at one level even improves it. However seeing this in person still captivates the soul in a more powerful way than this image can every communicate. In truth, real-time perception is a fleeting, chameleon like thing. There will always be another view, another distribution of light that evokes a fresh, undiscovered emotion. So even if we succeed in "improving" reality we will always return to savour or photograph it - it's allure will remain un-diminished and as powerful as ever.
In a sense Robert's words have thrown down an incredible challenge - improve on this, if you can or even dare.
The thing is though - even if we fall short, the act of trying to envision and implement a response to this challenge can only lead us to a new and better body of work.