It's hard to get access to moving images. Unless they have undergone an expensive preservation process, unique archival copies of films or videotapes may not be viewable without the risk of incurring damage. The cost of making viewing copies or production materials may be beyond the budgets of both institution and researcher. If you wish to view archival moving images, you may need to travel to a number of repositories in order to access physical materials. Finally, complex or uncertain rights situations may render certain material inaccessible or uncopyable.
Rights issues can complicate access.
Once you have identified archival material that you wish to see or reuse in a project, you may find that it isn't available because of copyright or other intellectual property restrictions. In many cases the owner of rights in a moving image document can't easily be identified, and it can also be difficult to determine what rights really need to be cleared in order to reuse the material. For more discussion of the Internet Moving Images Archive and public access to intellectual property, see Rick Prelinger's recent article in Bad Subjects.