1. Montage theory: Eisenstein
--juxtaposing images by editing--is unique to film (and now video).
During the 1920s, the pioneering Russian film directors and theorists
Sergei Eisenstein and Dziga Vertov demonstrated the technical,
aesthetic, and ideological potentials of montage. The 'new media'
theorist Lev Manovich has pointed out how much these experiments
of the 1920s underlie the aesthetics of contemporary video.
Eisenstein believed that film montage could create ideas or have an
impact beyond the individual images. Two or more images edited
together create a "tertium quid" (third thing) that makes the whole
greater than the sum of its individual parts.
Eisenstein's greatest demonstration of the power of montage comes
in the "Odessa Steps" sequence of his 1925 film Battleship Potemkin.
On the simplest level, montage allows Eisenstein to manipulate the
audience's perception of time by stretching out the crowd's flight
down the steps for seven minutes, several times longer than it would
take in real time:
The rapid progression and alternation of images gives a sensational
event even greater visceral impact:

2. The famous sequence involving a runaway baby carriage shows Eisenstein using
montage to arouse both emotion and ideological consciousness among the film's
viewers:

3. At the conclusion of the Odessa Steps sequence, two sequences of images illustrate
the notion of the 'tertium quid' as well as the ideological potential of montage. In the
first sequence below, the rapid montage of the three cherubs makes the small angel
seem to be throwing a punch. In the second sequence, three shots of stone lions,
shown rapidly in succession, indicate awakening militancy. In Potemkin, both
montages represent a call to the people to rise up against oppression.