Reflex photographs

Sequential photographs can be used to monitor pupil size over an extended time. If the pupil is illuminated with infrared fight and infrared-sensitive film is used, recordings can be made in total darkness. Although this method was used in seminal studies of the pupillary light reflex and other dynamic applications,6 7 it is seldom used today because of the high cost of film, processing time, and limited temporal resolution. 

To determine the best photographic method for die study of prehistoric textiles, experimentation with different light sources was necessary. A single lens reflex (SLR) film camera (Canon AE1) with an option for manual adjustments, and different macro and zoom lenses and filters were used for all photography. All pictures were taken with the samples placed on flocking paper (Edmund Scientific), which creates an optically inert background and therefore does not interfere with the optical properties of the textile to be examined. Details of the forensic photography methods are described in Baldia and Jakes (64, 65). 

Since the photographs will form a unique reference set for all sampling sites, it is important to ensure a good result. This means using a good camera. A reflex camera with a zoom lens (e.g. 35-85 mm) and macro facility is recommeded, and an electronic flash. 

Table 23 Photographic documentation using single-lens reflex cameras...

The energy spectra discussed below were obtained with a Packard Tricarb Spectrometer 3380, in combination with a Packard multi-channel analyser Spektrazoon 930. The spectra displayed on the screen of the multi-channel analyzer were photographed with a reflex Ccunera. 

Figure 29 CAM AG photodocumentation system consisting of Rcprostar II and Polaroid Land multipurpose reflex camera or optionally standard 35 mm camera (Photograph courtesy of CAMAG).

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