I sometimes get the feeling that people have this strange idea that by being assigned the film genre of “documentary” a film is automatically without subjectivity on behalf of the director, which in truth rarely happens.
Consider the film WINGED MIGRATION, which many hold as a shining example of a beautifully shot documentary about wildlife. How can one insert politics and remove objectivity when one’s shooting birds in their natural habitat one might ask. But objectivity is thrown out the window and politics are shoved, if subtly, onto a manipulated audience.
Winged Migration is full of staged scenes presented as “captured from nature”. Most of the birds used in the film were raised from hatchlings by animal trainers alongside the crew of the film in order to allow them to imprint on them so that they could be filmed from the ultralights and other vehicles as they flew.
The duck that escaped from a net early in the film thanks to a child with a nife, only to carry a piece of the net throughout the film. What you’re not told is the scene with the child was staged, and the net was removed at the end of each day’s filming and tied back on at the beginning of each new day in order to create a “moving symbol of man’s world and it’s affect on animal life”.
There’s also a scene in which a rusting truck surrounded by litter is seen in the middle of the pristine desert. You’re not told that the truck in question was actually hauled into that desert by the filmakers in order to create the “mood” of that scene.
Finally, consider how Europe is portrayed in the movie, with most scenes involving ugly, polluting factories being everywhere, and a completely staged scene in which a bird sinking in oil … except that the bird in question was put there by the filmmakers and “rescued” as soon as the filming stopped.
It’s all subjective, because you can use all the tricks one does in normal movie making to portray the same person, place or thing in a different light depending on how you do it.