There are about 15,000 cans of film in our vaults - ranging from full prints of professionally made films that were released commercially to advertising footage and people's home movies.

Part of the purpose of an archive like this is to say: yes, Ireland does have a history of film - it didn't all begin with My Left Foot. There have been films produced here since virtually the earliest days of cinema.

Nonetheless, the fact that there were relatively few professional fiction films made here until recent times means that we are also free to concentrate on other sorts of film: educational films made by the government over the years, for example, or footage shot by amateur enthusiasts. In Britain, for example, amateur "home movies" tend to be held only in regional archives; here, we consider it all to be of "national interest".

Often people who are donating a collection of old movies will say: "Some of it is of historical interest" - they usually mean there are images of a taoiseach or a government minister. They have to be convinced that the material they think is of little interest may be the most important as a social document.

Film-making in the past was a fairly expensive hobby. We've found that the clergy, parish priests, were a significant film-making group. First, they could afford the equipment and, second, they seem to have recognised the value of making some record of their communities and events there. Just a few weeks ago we got film shot by a priest in the Gardiner Street and Summerhill area of inner-city Dublin in the 1930s - and you could see that, yes, kids were going to school barefoot in winter, for example.

We have a huge backlog of material that's been donated that still needs to be catalogued - that means we look at it and make extensive notes about its condition and specific contents. We prioritise those small, amateur, private donations, the "home movies", so we are sure to have a chance to sit down with the donor and go through it with them, finding out what he or she knows about the content.

With professional collections it can take up to two years from acquisition to cataloguing. The backlog can grow suddenly and unexpectedly: a casual contact with an advertising agency, for example, can result in a truckload of film arriving the next day. We're now getting more selective about what we'll actually take. We also keep posters and stills like the ones used on this page.

Nowadays there is a master's degree in film archiving at the University of East Anglia, but I came into this archive 11 years ago (when it was at a different location) on an employment scheme. A couple of years later I did a sort of apprenticeship in the National Film and TV Archive in London, but we're learning all the time from the experiences of other archives internationally - and from their mistakes.

There's constant discussion internationally among archivists about diseases that affect films - like "vinegar syndrome", an acetic-acid attack on the film. I can confidently say that, with new vaults opening shortly, we're achieving the proper levels of temperature and humidity that will inhibit further deterioration of any film we hold here.

My typical day's work involves a lot of dealing with the public. These are often students, who perhaps want to see the work of a particular filmmaker or, say, films about Northern Ireland. I can use our computer database to produce a list of films that might be relevant, then sit down and advise them about films they might like to see. Then we can organise for them to view the film here.

The most demanding, most complicated dealings I have are with TV programme-makers. The benefits, though, are great: not only is the archive credited in whatever programme is produced, but we insist that, even if the programme-maker wants to use just a short clip of a film, they should pay for the transfer of the whole film to video. Also, we'll search the copyright on the film if they want to use it; in fact, the possibility of getting a payment from programme-makers is something that donors are reminded of - it makes donating that much more attractive. A couple of years ago - coming up to the centenary year of cinema - I was very busy helping international film festivals put together programmes on Irish cinema. We'd provide prints and information on where prints can be found, and help clear films for exhibition purposes. That trend seems to have more or less passed - and that work, at least, has eased off.

In an interview with Harry Browne