First, this beautifully written essay by Hanya Yanagihara for The New Yorker discusses the photographer's ability to disappear in order to document.
"…if love belongs to the poet, and fear to the novelist, then loneliness belongs to the photographer. To be a photographer is to willingly enter the world of the lonely, because it is an artistic exercise in invisibility. …the person with the camera is not hiding but receding. She is willfully removing herself from the slipstream of life; she is making herself into a constant witness, someone who lives to see the lives of others, not to be seen herself."
In a similar light, this piece by Ed Kashi for TIME was incredible to read. It's pretty rare to see someone talk about the challenges of the profession with such vulnerability.
"But most of the time I’m alone perfecting my disappearing act. The result is a deep sense of loneliness and abject uncertainty. I have been exposed to pain, suffering, violence and death, the cumulative effects of which have posited me into voids of nothingness more often than I ever could have imagined, and more often than my wife deserves to have to live with."