Eisenstein On Montage:
In Eisenstein’s essay he describes five methods of montage. These different forms of montage build upon each other. So that the higher forms of montage include the simpler forms, or the lower levels of montage. The lower forms of montage are limited as to the complexity of meaning, however as the montage rises in complexity, so will the meaning that is being communicated. They begin as primal emotions and rise to intellectual levels. 
Then he goes on to explain his theory of the different formal types of montage.
Described as absolute lengths of the pieces. Tension is obtained by the effect of mechanical acceleration by shortening the pieces while preserving the original proportions of the formula. This technique produces a quantitative effect that can be reduced to a mathematical formula.
This technique incorporates not only the metric composition but equally within the content of the frame is also considered. In this description Eisenstein states, “Formal tension by acceleration is obtained by shortening the pieces… but also by violating the plan.” Example: Potemkin The Odessa Steps The rhythmic drum of the soldiers’ feet… violates all metric demands. 
This montage represents a stage beyond rhythmic montage. He continues, “It is not only movement within the frame, but movement perceived in a wider sense. This montage is based on the emotional sound of the piece.”
In the “fog sequence” during Potemkin, this montage was based exclusively on the emotional sound of the piece. However both tonal and rhythmic dominants are operating.
The chief indicator of assembly of the pieces was according to their basic element, light-vibrations (the varying degrees of haze and luminosity).  Moreover this example furnishes a demonstration of consonance in combining movement as change and movement as light-vibration.