By way of introduction
Ethnomethodology is a not a methodology. It is the study of members' methods. Or, less bluntly, the investigation of practical reasoning through the relationship between human practices and accounts of those practices (and, more confusingly, that the practices are, at source, already accounts).
Actor-network theory is not a theory it is a methodology (according to Bruno Latour (and who better to make such a remark)).
(Oskar Lindwall & Jonas Ivarsson at Video of Video workshop FRIAS, 2010)
By way of a sense of how I work with video
For a decade or so now I have been learning how to shoot video and how to watch it afterwards. There are no great mysteries to either part. I am not particularly good at the first part. No better than any other amateur film-maker. Over the years I have learnt a trick or two with foam and when (and when not) to attach semi fish-eye lenses.
Most social scientists are in a hurry with video footage. One of the ambitions of e-social science, for instance, is to have software that would 'image-crunch' hundreds of hours of video records into digestible summary statistics of the contents of those images. What I have learnt from conversation analysis is, not so much the array of conversational features it has identified, as the patience and care with which its practitioners examine recordings of social action. They will spend two hours examining three seconds of video footage, often three seconds that are almost perversely ordinary and uneventful. From extending the contemplation that literary critics would devote to Shakespeare to how praise is offered by one friend to another over a cup of coffee during their morning break, I have come to appreciate the wonder and ignored skill of our everyday accomplishments.
Each week two, three or as many as ten of us at SEDIT try to spend at least two hours watching a video clip and making notes on what's happening in it and how that thing is being accomplished by those present with whatever resources they have at hand. We look at clips of: colleagues complaining about other colleagues in cars, children playing in nursery, high rise concierges finding keys for maintenance crews, martial arts instruction, ufo-sightings and more.
There is no necessary link between video and ethnomethodology, it just happens that a lot of members of that community use it, finding it germane for studying human practices.
As an empirical material, or rather assembly of materials (or rather practices of material assembly and analysis), video is also, fun. If you want to learn more then visit my online module.