Larry Gottheim's 1970 short film Fog Line is just beautiful to watch. 11 minutes of fog imperceptibly but inexorably dissipating in a rural landscape.
It reminds me a bit of Tacita Dean's Banewl, a 63-minute fixed shot of a Cornish cow pasture during a 1999 solar eclipse--only without all the action.
In 2005, the NY Film Festival hada mini-retrospective screening of Gottheim's work, including Fog Line.