Harun Farocki's documentary Images of the World and the Inscription of War is available in English on YouTube in 8 parts. (Click here for part 1). Two highlights:

The idea of obtaining measurement through photography came to [the inventor of the technique] after he was suspended between life and death. That means, it is dangerous to hold out physically on the spot... safer to take a picture.
...
Arduous and dangerous to hold out physically on the spot. Safer to take a picture and evaluate it later protected from the elements at one's desk.

***

[On the examination of aerial photographs of concentration camps in the 1960s and 1970s:]
The snow on the roofs of the neighboring barracks is already melting, which means that they are still inhabited. The evaluators verify, that means they establish the verity, of the existence of the camp down to the last detail, and they do this with relish for their role as specialists.

Although the film is about many things, it is basically about the Holocaust. In this regard and in others, it is the same color as W. G. Sebald's book The Rings of Saturn, which, although it never mentions the Holocaust directly, is basically "about" the Holocaust in the sense of "around".

In China, the placating of the elements has always been intimately connected with the ceremonial rites which surrounded the ruler on the dragon throne and which governed everything from affairs of state down to daily ablutions, rituals that also served to legitimize and immortalize the immense profane power that was focused in the person of the emperor. At any moment of the day or night, the members of the imperial household, which numbered more than six thousand and consisted exclusively of eunuchs and women, would be circling, on precisely defined orbits, the sole male inhabitant of the Forbidden City that lay concealed behind purple-coloured walls. In the latter half of the nineteenth century, the ritualization of imperial power was at its most elaborate: at the same time, that power itself was by now almost completely hollowed out. While all court appointments, rigidly controlled as they were by an immutable hierarchy, continued to be made according to rules that had been perfected down to the last detail, the empire in its entirety was on the brink of collapse, owing to mounting pressure from enemies both within and without.

I read this book some months ago, but I didn't realize that it was about the Holocaust at all until I heard a radio interview with the author in which he explains it. Originally I was unimpressed, since I don't like puzzles that can't be figured out and I don't like art that can't stand alone. With time, though, I've come to the conclusion that the Holocaust serves in both these cases as a horizon against which concepts can be set. It's not necessary to understand the horizon in order to use it as a new way of linking concepts, a new way of thinking. The point, rather, is that historical events create interpretive possibilities, possible routes to the truth, that did not exist before. And the method is an innocent one because the truth always stands alone.

Brief clips of many of Harun Farocki's other excellent documentaries (most of them are not feature length) can be found on YouTube and here.