I know I'm joining this thread slightly late, and I realise that many of the points in the following post have been made by previous members. In addition to demonstrating that the digital / film question is not as black and white (sorry!) as digital = shiny, modern and good, film = outdated, old-fashioned and bad, the original post raises a number of other issues.
Trowelhead said that the use of film cameras was specified in a WSI. However, WSIs are prepared by the contractor on behalf of their client, and submitted to the Council's archaeologist and planning department for agreement. Provided that the programme of works set out in the WSI, including the recording methodology, is appropriate to the requirements of the project, the Council's archaeologist would have no reason to ask for changes. Trowelhead's profile indicates that he's a consultant, and as such, it may be that the proposal to use film cameras has come from the contractor appointed by Trowelhead's own company, and the Council either hasn't yet seen the WSI, as it's been submitted to Trowelhead's consultancy first, or has had no reason to ask for amendments as the proposal to use a combination of digital and film cameras would adequately meet the recording requirements of the project. I've got no details of the specific project to which Trowelhead is referring, but there's certainly nothing in our standard conditions for fieldwork that specifies the use of either film or digital.
We generally specify our standing building survey conditions in relation to the 2006 English Heritage standards, as noted above by Dr Peter (though I know that the East Lothian standard for recording buildings, as promoted above by David, is a mighty fine document). We would generally ask for, for example, a level 2 survey of a specific building in accordance with these standards. In that situation, however, the requirement to use film as well as / in preference to digital cameras would come from the English Heritage document, rather than specifically from the SMR. This raises the issue of where site archive photographs are held. In Scotland at least, site archives (both physical and digital) are generally deposited with the RCAHMS rather than the local SMR / HER. The local authority archaeologist(s) will generally receive a copy of any final site report for archiving, and will integrate the results of the fieldwork into the SMR in order to inform future planning decisions. However, they will not generally hold the bulk of the raw site archive data generated as a result of the fieldwork. On that basis, it seems reasonable that organizations that are responsible for the long-term storage and maintenance of this archive material, such as RCAHMS, RCAHMW and English Heritage / NMRE, should have some say in the format that they'd consider most appropriate for data submission. The SMR / HER may never actually receive the complete site archive, but would nevertheless want to ensure that it is of an acceptable standard and format for submission to these data repositories. The most straightforward way of achieving this would seem to be to request that contractors meet the deposition standards set by the organisation that will hold the data in the long term. I don't think it's particularly unreasonable to reproduce a requirement to take film record shots in addition to digital if the people who'll have to look after the archive in the longer term consider it necessary, and I also don't think it's a particularly onerous requirement to contractors. However, I do think that there are valid reasons why there's still a place for film photography.
While I do think that the long term stability and accessibility of data is a valid concern, I'm not sure that it's necessarily as big a problem as it may have been previously. While external storage media may not prove to be sufficiently durable over longer periods, I think that most digital site archive material will now generally be aggregated onto servers at a national or regional repository, rather than existing solely on the portable media on which it was submitted. That being the case, it would tend to be migrated along with other data as these servers are replaced or upgraded. However, as Anna said, this type of 'active' management would tend to come with a cost for the repository. While there may be issues over accessing obsolete file formats, I would imagine that translators for the formats widely used today would be easily available, certainly for the foreseeable future, and even if they weren't, the option would remain to retrieve the image from the raw data.
Although I don't think that the issue of file format obsolescence is necessarily an insurmountable one, therefore, I do think there may be an issue raised by the current level of digital camera technology, particularly in terms of variations between the equipment used by contractors, as previously noted by Dr Peter. I've heard it suggested that to match the resolution achievable using a combination of good quality film and camera, you'd need a digital camera with a resolution of at least 16MP. Most contractors I know use cameras in the 5 to 8MP range, with most around the lower end of this scale, which is obviously fine for general working shots and day-to-day use. However, this must surely represent some degree of compromise in the quality of the archive record, particularly towards the lower end of the MP range, as there is a potential for details to be lost due to a lack of achievable resolution. It can be incredibly annoying to zoom in to some architectural detail or feature on a digital aerial photograph, only for the relevant section to get lost as the image pixellates. Given that these survey shots may represent the last or only visual record of a structure or site, surely it's not unreasonable to take precautions to ensure that images exist of sufficient quality to serve as an adequate record? The use of film cameras does at least ensure a certain base level of quality, given the wide variation in the resolution of digital cameras in use among archaeological contracting companies. The only way of achieving a similar base level in a purely digital environment would be to specify that all contractors must use, as a minimum, say 10MP digital cameras. I don't think it would go down well with all the contractors who are currently using 6, 7 or 8MP cameras if we told them to chuck them out and buy a higher spec, so until digital camera technology reaches the point where the use of such high resolutions are the norm rather than the exception, and some of the cameras currently in use by contractors reach the end of their natural lifespan, it seems to make sense to ensure that there's also a good quality film photo to guarantee a certain base level of record. The routine use of such high resolution digital cameras will also carry an overhead in terms of the storage requirements of organisations such as RCAHMS. High resolution digital photographs routinely run to several megabytes, and site archives can run to several thousand images. This again highlights the need for the organisation that will hold the archive in the long term to be involved in specifying appropriate standards for data deposition.
I realise that this has been a fairly long post, so if anyone's still reading, I'd like to sign off by suggesting to all contractors that if you have an issue with specifications set by a curator, try contacting them directly to discuss the matter. I hope that we're not seen as so unapproachable that people wouldn't feel able to make suggestions of ways they think things could be done better (though obviously, this represents my own personal opinion only, and should not be taken as representative of the opinions of curators as a whole
)
Martin O'Hare
SMR Officer, West of Scotland Archaeology Service
