I have always said that the most useful photographic tool for a landscape photographer is a pair of legs. Well before we start composing a photograph, we need to decide where we are going to stand. Camera position is of paramount importance since it defines the perspective.
According to the Merriam-Webster dictionary, one of the definitions of perspective is "the interrelation in which a subject or its parts are mentally viewed". We photographers could modify that definition into "the interrelation in which the different elements we see in the frame appear in the final photograph ". Once the camera position is chosen, perspective is univocally defined and there is no way back, no matter how much we crop or reframe our photograph later on.
However, this important concept and its essential implications are often not retained in the mind of many photographers. I have seen innumerable photographers arrive at a certain location, step down from the car, set up the tripod at eye level, place the camera on top and then spend their time zooming, changing from horizontal to vertical, spinning the camera around the ball head and finally taking the photograph without ever moving from the position they landed on.
It is important that the photographer adopts an active approach in photography. Even if the location, subject and focal length are defined, a certain landscape will never be unique, but infinite. In fact, at every single step we make the landscape is transformed completely. As we move horizontally, tree trunks in the forest seem to move sideways, changing their disposition, some trees hiding, others converging and some others reappearing... As we climb onto a rock, or crouch, the vertical perspective changes, maybe allowing us to see a great expanse of lavender fields or on the contrary collapsing the ground into a thin band in our photograph. Not only that, as we get closer or farther from subjects, we can change the relative size of the different elements in our image.
This last aspect is frequently forgotten or even misunderstood. I have often heard it said that fixed focal length lenses force you to move, that wide angle lenses exaggerate perspective or that long lenses flatten it out. Focal length has nothing to do with perspective. When we use our legs and get closer to any subject, its size in the frame increases proportionally to the reduction of our distance to it. Let us suppose we have in our frame a tree at 20 metres and a mountain at 2 kilometres. If we advance by 10 metres, we will have reduced the distance to the tree by a half, and thereby doubled the size of it in the photograph. However, the distance to the mountain will have been reduced from 2 kilometres to 1.990 kilometres, barely changing its apparent size in the photograph. By using our legs, we can make the relative sizes of the different elements adopt the exact proportion we want for our composition.
By changing the focal length, however, we only crop in or out of a frame into that unique perspective given by a fixed camera position. A wide angle will show a wider angle and a telephoto will only show a small frame within the frame. However, the relative position and relative size of each of the elements that compose the landscape will never change. Wide angle lenses exaggerate the perspective not due to the focal length, but only because while using them we normally get closer to a foreground, exaggerating its size in respect to the rest of the image.
We landscape photographers should play an active role in finding "our" landscape. Setting the tripod close to our car where we happen to pull up is equivalent to throwing a stone blindfolded and then taking the photograph from the place the stone landed. If the camera position is not chosen carefully and deliberately, the chances of creating a truly effective photograph are almost zero.