Documentaries are self propaganda.
"Documentaries portray the truth!"
If you still think this, I suggest stopping at the end of this sentence and beginning this blog again from post one.
Documentaries, as you know, are continually and instantaneously communicating a multitude of ideas outside of the depicted subject.
Ideas related to form, structure, hierarchies, associations, biases, etc.
But one of the most important things the documentary will be communicating to the audience is a story about you: the filmmaker.
No matter how you make the film, the film is in some way about you.
Here's my take on this: If this is going to be the case ANYWAY, then why not, for the time being, construct the subconscious depiction of yourself as one that's enviable and favorable?
What do I mean?
Well, the idea is to create rapport between your on-screen (or off-screen) personality and the audience.
By thinking upon and manufacturing this process, you will be able to create a cult of personality around your image as a filmmaker.
To not do this is to have a half a movie.
So for example: "The Wolfpack" by Crystal Moselle lacks her direct input into the depicted narrative, but it also lacks any focused indirect characterization of herself.
There is an aspect to the film surrounding the mystery of how she got access to the subjects. But this point isn't explored very far, and isn't enough to sustain the duration of the movie.
Outside of the initial shock of the story, the drama peters to a flatline.
I suggest, with more direct input from the director during the production, or the stronger insertion of her voice narrating the events, or retelling them, would have increased the entertainment value of the movie - and worked for her personal brand in the long run.
In a Frederick Wiseman film, for example, although he is purposefully left out of the narrative entirely, there's always a sense, scene-for-scene, of his presence: how he must've gotten access to where the camera is, how bold he is for getting so close to the subject, the joy and utter craftsmanship of the rare coincidence captured on film (and the superhuman patience it must have required to get it), etc.
It's as if Wiseman only completes a movie when a certain percentage of highly-charged verite sequences have been captured - sequences which would cause the audience to identify with (and question) the man behind the camera - thus slowly building a cult of personality.
He may not have done this purposefully, either. But that is the net result.
And, in my opinion, it's one of the contributing factors to Mr. Wiseman's success.
In a film by Nick Broomfield, he directly involves his actions on camera, highlighting his method and wit.
This has helped him create not only memorable movies, but a positive personal brand out of a medium which would've built him a brand anyway.
Yet there's still an air of verite, that feeling of what you see is what you get... just filtered through Nick's perspective.
Then there's filmmakers like Werner Herzog, with whom you never know if what you see is what really happened.
His documentaries are like poetic humbugs.
And yet there's the constant identification with his character (his characteristic accented voice, his reaches of logic and bold metaphysical conclusions, his geographical adventures): this aspect alone may be the reason why Herzog became so popular.
The point is that documentaries also tell the story about you making the documentary.
This is true whether you're on camera or not.
Give this thought, and consider how you could use this to your advantage.
Every slight edge matters.