Digitisation
The National Monuments Record of Wales has an active digitisation programme, producing digital versions of selected hard-copy records from its archive holdings, which are made directly available to the public online via the Coflein system. We have created a professionally equipped digitisation suite, utilising the following scanning equipment and peripherals:
Batch negative and photographic prints or small drawings scanner – Lanovia Quattro
Large-format drawings, plans and outsize prints scanner – ColourTrac 4280
Scanning equipment operated through – Apple Powermac G5
Scanning equipment fully calibrated with monitors using – Pantone ColorVision Spyder
The digitisation room is up lit and painted in a recommended shade of matt grey (Dulux Ice Storm 3 12626), in order to minimise interference from reflected light.
All image files are produced and preserved in uncompressed .TIFF format, and the colour IIC profile used is RGB.
Although the individual digitisation parameters used in scanning archive originals vary depending on the nature of the original, the information it contains and the possible required output, there are basic standards for digitising National Monuments Record of Wales archive images. These constitute the minimum desirable standard, but in many circumstances higher parameters are applied, depending on the detail of the original and the desired final output.
All images are scanned to at least 300dpi.
The size of output of any original is dependant on the amount of information held in the image, its quality and potential for reproduction. For instance, 645mm and 6x6cm negatives or transparencies are frequently aerial views which may require enlargement for research purposes. If no enlargement is required, or is not desirable due to lack of quality or detail in an image, an output size of 14x9 inches may be adequate. Similarly, 6x7cm and 5x4 inches film images may be suitable for exhibition purposes, due to their expected high quality, and could warrant a larger output size. The following is a guide to minimum desirable output sizes for several standard negative and transparency formats.
Black & white negatives or transparencies, scanned at 300dpi 8bit (greyscale):
35mm to an output size of 14x9 inches. File size approx.10MB.
64.5mm (21/2 inch) to an output size of 15x11 inches. File size approx. 12MB.
6x6cm (21/4 inch) to an output size of 15x15 inches. File size approx. 14MB.
6x7cm to an output size of 17x14 inches. File size approx. 15MB.
5x4 inches to an output size of 20x16 inches. File size approx. 25MB.
Colour negatives or transparencies scanned at 300dpi 24bit (RGB):
35mm to an output size of 14x9 inches. File size approx. 35MB.
64.5mm (21/2 inches) to an output size of 15x11 inches. File size approx. 40MB.
6x6cm (21/4 inches) to an output size of 15x15 inches. File size approx. 50MB.
6x7cm to an output size of 17x14 inches. File size approx. 60MB.
5x4 inches to an output size of 20x16 inches. File size approx. 80MB.
Photographic Prints
Where no negative or transparency is available, prints are scanned at a minimum of 100 per cent of the original size. Where the quality and detail allows, prints may be enlarged to capture the maximum information.
Drawings
As drawing sizes, level of detail, tone and shading vary considerably, written guide standards for drawings are difficult to employ. The parameters for production of digitised drawings are set on an individual basis by our experienced Digitisation Officer, who takes into account both the nature of the original and the likely outputs.
Cataloguing and Storage
The specific technical metadata relevant to digital records are recorded in a Digital Instance data table within our computerised archive record catalogue. Each entry on this may relate either to a catalogue entry for a hard-copy original or an entry for a 'born digital' item. The standard of technical metadata recorded in this table is informed by several guides to good practice and standards. For further information on technical metadata, the Archaeological Data Service provides a comprehensive guide.
Our digital archive files are stored on a remote archive hard drive, hosted by the Royal Commission on the Ancient and Historical Monuments of Scotland, in Edinburgh, who also store off-site back-ups.