Page 308 - Green - Maritime Archaeology: A Technical Handbook. 2nd ed

Chapter 10: Recording 287
on a sheet of glass leveled over the object and use the reflection of one’s eye in the glass to align the features ensuring that the tracing does not suffer from parallax. In this way, an accurate plan of the curved surface can be made. The tracing material has to be clear film, in order to see the reflec- tion, otherwise some other sighting device can be used.
When photographing large objects, a permanent tower is preferable. The subject to be photographed should be shaded from direct sunlight and for convenience of printing the scale should be kept constant. It is absolutely essential that the camera, the object, and the scale are all leveled. A simple method is to have a table on which the object is placed. The camera is set on a tower and leveled relative to the table using a mirror (as described in Chapter 12). The object can then be leveled relative to the table, using packing. A scale is then placed on the table and adjusted to be level with the upper face of the object. A slate with the registration number and other details is then placed on the table and the photograph is taken (Figure 10.8). For details of exposure setting for timber, see Chapter 12.
Another area where special methods of recording are required is with complex objects, particularly concretions, where the material has to be systematically excavated from inside the concretion. The concretion, for example, may be broken into several large pieces and some form of pre- liminary re-assembly may first be necessary. Each fragment can be given a separate registration number, and its position and how it fits together can
Figure 10.8 Recording photograph of part of the stern post of the Batavia. The timbers were placed on a leveled table under a leveled camera. A scale and information board were always included in each photograph. (Courtesy of Patrick Baker, Department of Maritime Archae- ology, Western Australian Maritime Museum.)