The true power of ethnography is in its exploration of the social, team, political and organizational influences that guide the opinions and decisions made by humans.
It is rooted in the principle that individual views and decisions are guided by culture as much as they are, well, by anything else. This is an intuitive posture, and it is very applicable to the design of UX.
It's a place where you continue to collect data until you get to the point where you stop listening to new things.
People: Include a shot in the head of the people observed
Place: Capture the general environment in which the observation is made.
Activities: Take pictures of what people are doing during the observation.
Ambient: Capture close-up shots of nonverbal cues and emotions
Things: Take pictures of things and objects that they use, show or show.