Page 245 - Green - Maritime Archaeology: A Technical Handbook. 2nd ed

224 Maritime Archaeology: A Technical Handbook, Second Edition
tanks are required to take the longer film, otherwise the processing is conventional.
Finally, the introduction of digital cameras is rapidly changing most of this technology and one wonders if black and white film will be available in a few years time. Clearly, the same principles apply to digital cameras and the relationship between speed and aperture still exists, although it is purely for the photographer. The automatic exposure systems can be set or programmed to be biased toward speed (the usual situation under water) or aperture. The ability of the digital camera to deal with extremely low light levels is phenomenal, and provided one can mount or clamp the camera in a fixed position some surprisingly good results can be obtained.
D. MISCELLANEOUS
Finally, a diver has to resolve the problem of how to carry all the bits and pieces that have to be taken under water. At times, a diver can look a bit like a Christmas tree. It is worth considering mounting the camera and exposure meter on a bar. The bar holds the camera and the exposure meter and provides a handle so that everything becomes an integral unit, all con- trols can be checked at a glance, and system can be picked up or put down as one. Interestingly, it does not make the unloading of film any more dif- ficult with the Nikonos system because the camera base is bolted to the bar, but the body can still be removed from the top.
In most field situations where conventional photographic information will be required, the construction of a field darkroom will be essential. This may be just a simple tent which is light-proofed with black plastic, a blacked-out room, or a place used only at night. The basic necessities will be a small, portable field enlarger and some simple darkroom fittings includ- ing: safe light, developing trays, timer, contact printer, framer, or measuring jugs. All of which can be made to fit into a small suitcase for easy trans- portation. The advantages of having on-the-spot results are immense. Prints can be made within a few minutes and used directly in discussion on aspects of survey or excavation and the results are available for producing plans and surveys as the work proceeds. In addition, the photographic film can be processed to ensure that the proper coverage is being made and that the cameras are functioning properly. Even if a darkroom is not available, the processing can be done using daylight loading tanks (Agfa Rondinax), which are also economical on chemicals. Again digital photography is largely replacing these requirements and all one needs is a laptop computer. In some cases it is not even essential to have a printer.