As part of the five year plan to reappraise the work carried out on the Ashtead Roman Villa site, we have recently undertaken a project to maximise the information we can obtain from the artefacts using digital photography. All artefacts have a story to tell and it is important to extract as much information as we can from our photographic images.

Equipment

We have been used a Canon EOS 30D camera with an EF-S 18-55mm lens. It is “tethered” to a Dell Inspiron laptop using Canon dedicated software to capture “Raw” images which are easier to manipulate before saving as JPEGs.
An object stand is used with a vertical column fitted and an adjustable horizontal arm to hold the camera. Two lighting arms were used fitted with Tungsten bulbs. This enables longer exposures and thereby a corresponding reduction in aperture to produce a greater depth of focus than would be available from a hand-held camera.

Tungsten lighting has proved to be the most effective light source for photographing the artefacts. Its direction and intensity can be carefully controlled and the effect can be seen before the photograph is taken, which is not the case with a flash. Where necessary the light can be diffused to produce a softer tone.

The “tethering” software permits adjustment of camera settings (i.e. exposure and aperture), firing the camera and viewing the resulting image on screen. Unsatisfactory images can be rejected and replaced in a matter of seconds and one knows that the retained images are of the quality desired.

Why use digital?

For our purposes digital was the most obvious choice for several reasons. We are undertaking photographic recording of a large assemblage of artefacts, therefore speed is a factor. We work as a team; one placing, lighting and picturing the artefacts, the other processing the image immediately on the laptop. The technology is user friendly and allows manipulation of the image to achieve exceptional results. Furthermore, modern archiving practice encourages use of digital images although this can be expensive and should be used selectively.

Although the longevity of present-day storage media is an unknown quantity, it is well known that photographic prints also deteriorate over time.

Manipulation of images

All forms of lighting create a colour cast – in the case of Tungsten light this is a warm yellow; flash light imparts a pale blue cast. The software enables these casts to be removed thereby producing a faithful representation. The brightness of the image, colour balance and density can also be adjusted, if necessary and as required, without the need for a replacement exposure.

Future work

Continuing work on the site archive will include a visit to the British Museum to photograph their artefacts from Ashtead and also to photographically record the small finds housed in Guildford Museum.