Digital video is becoming more and more popular as a means of recording both archaeology and events related to archaeological investigation such as surveys, procedures and interviews. Whereas, as noted by Internet Archaeology in 1997 in a EVA Conference paper, few archaeologists previously had access to the technology to create digital video, the situation today has moved along so rapidly that the ability to record digital video has not only become cheaper and easier but the technology itself is also now a common feature of other devices such as still image cameras and mobile phones. A rapid advance can also be seen in terms of the ease and availability of video editing and dissemination applications, particularly in terms of web-based dissemination on popular sites such as YouTube and Facebook. As a result, digital video is now often a common component of an archaeological project whether as a planned 'output' or not.
How is it used?
Digital video is often used in the field as a tool to accompany, document and supplement other data collection techniques. In particular, digital video is often a common component of survey projects particularly amongst maritime archaeologists where sites are less easily accessible than those on dry land. In addition, digital video can also form a simple output from projects employing a wide variety of data collection and analysis techniques such as 3D modelling or virtual reality in which a video 'fly-through' is produced as an easy way to engage with modelled data.
I terms of creating data, captured digital video is often recorded directly onto DV tape or DVD but, as stated previously, can also be captured via other devices such as still camera and mobile phones or derived from other sources of data such as 3D models. As will be discussed in the following section, the method in which the video is created can often determine the file type, size and quality of the video. In some cases, such as DV tape and DVD-based cameras, a specific file is often not actually created and further processing on a computer is required in order to generate one. Other devices, such as still cameras, may also be highly restrictive in terms of the file types that they produce.
Reasons for archiving
The case for archiving digital video created from archaeology projects depends largely on the original intended purpose and must be weighed against the issues discussed below. A case for preserving digital video can be made where it contains unique original data (i.e. not recorded in another format such as photographs) or provides valuable support and documentation to other datasets. In the case of the Wessex Wrecks on the Seabed project, digital video in a maritime context provided an important record of what was seen by the diver or ROV at particular points on the underwater site, especially when associated with a track log (see sections in the VENUS Guide on Navigational and Positional data). Though not many future users would wish to view full un-edited footage of the dive, it is seen to be important to preserve this information. Digital video could be utilised as a tool to assess the condition of a wreck site and monitor damage over time. In short it pulls together components of a project just as the traditional paper site diary and more recent video diaries do. Such videos also become a source for historiography.
In the case of 3D modelling and interactive 3D environments, video created either of users within the environment or of simply a fly-through of the environment/model itself can also provide valuable documentation which is not easily stored in other formats. In addition, video fly-throughs themselves can provide a simple means to disseminate large scale 3D datasets and for users to quickly evaluate their contents.
A common issue with digital video is that the data itself in a 'raw' high quality format can be very large e.g. the Wrecks on the Seabed project produced around 40 hours of digital video. If 'cleaner' edited versions of video footage are produced, e.g. showing some of the highlights of a dive, then it is important that informed decisions are made on what versions should be preserved and in what quality format. Such decisions should also be weighed against the purpose of the file e.g. is it the sole documentation or merely supportive of other datasets? In addition, DV tape has an increasingly short lifespan and should ideally be migrated to disc based storage. DVDs also have a finite lifespan with hard drives (internal or external) providing the securest medium for storage.