Page 7 - brynecache2016
P. 7

combination of laser scanning and photogrammetry required a total of 12 hours of field effort, divided
               between two days.
                       Laser scanning utilized a FARO Focus 3D laser scanner with resolution set to ¼, and quality at 4X.
               A total of 18 scans were made of the baskets and rock shelter. These were divided between seven scans
               outside of the cave feature, and 11 within the cave. Three one-meter scales were used outside of the shelter,
               while six 10-cm scales were used within the shelter.
                       Photogrammetry modeling was undertaken using two full frame 36.3 megapixel Nikon  D800
               cameras. Two lenses were utilized:  a Nikon 18-35 mm f/2.8 and a Nikon 28-70 mm f/2.8. Three one-meter
               scales were used outside of the shelter, while six 10-cm scales were used within the shelter.
                       Photographing the cache presented unique difficulties. The high dynamic range of the contrasting
               light conditions, exceptionally low light, confined  spaces, dust, and a high potential for accidental
               movement of the stone platform resulted in a slow and tedious process.
                       The initial effort to model began during midafternoon, due to the orientation of the draw. Midday
               and afternoon lighting presented unforeseen extremes of contrast between illuminated and darkened
               portions of the cache which resulted in loss of details, image distortion, and data loss through blowouts and
               shadows of light. Exacerbating the issues, due to the strong contrasts of light, and uniquely confining nature
               of the cave, the use of auxiliary flash units was unfeasible.
                       The following day, photogrammetry began at dusk to allow artificial lighting of the assemblage.
               Three handheld LED panels were used to light the cache. Photographs were taken with 20-second exposures
               at ISO 100 and at f/22, each image was individually hand painted with LEDs, allowing even lighting over
               the entire cache without blowouts from highlights or blackouts from shadows (Figure 6).
                       In total, 350 images were taken of the cache. These were color corrected, adjusted for contrast and
               brightness, and corrected for lens distortion in Photoshop CS6 prior to  modeling. Modeling was
               accomplished with Agisoft PhotoscanPro. This model is to be merged with the FARO data to create an
               immersive and high fidelity 3D model of the cache in situ that will be accompany the large basket on display
               at the Santa Barbara Museum of Natural History. The model also will be developed into an interactive
               website and forms an exceptionally detailed addition to the site record form—allowing future researchers
               the ability to access an in situ cache.

                       Almost exactly 30 years ago, and very near the present cache shelter, John Johnson of the Santa
               Barbara Museum of Natural History recorded another cache location, known as Año Nuevo Cache (SBA-
               1985). The SBA-1985 cache contained portions of two small, twined water bottles and three long sticks
               (Johnson 1985). The three sticks appeared to partially define the basketry cache and the central basket rested
               on a small slab of sandstone. Although the three sticks did not have any obvious function, they may
               represent cave sticks (Whitby 2012:358).
                       Also in relatively close proximity to the Bryne Cache are three pictograph sites (SBA-1668, -1669,
               and -1984). All three pictograph sites also contain bedrock mortars and/or cupules. The presence of multiple
               cache caves, pictograph sites, and bedrock mortars (BRMs) in the Santa Barbara backcountry suggests that
               there may be a relationship between these three site types, at least in this area (Whitby 2012:359, 433).
               Robinson (2006; 2010; 2011) has demonstrated a link between pictograph sites and BRMs, particularly in
               the San Emigdio region. Cache caves may also be related to the activities taking place at the other site types
               (Whitby 2012:359). Whitby (2012:433) suggests that caching in caves and the use/production of rock art
               may have been integral parts of the food resource gathering/processing/storage regime.
                       Of the three types of caching identified by Whitby (2012:423-434), the present cache cave appears
               to represent Type 3 caching, that is, the cave appears to be related to the caching of equipment used for
               hunting and gathering or food resources such as nuts and seeds (Whitby 2012:429-430). Whitby (2012:430)
               observes that storage of food resources would have been vitally important to indigenous hunter-gatherer

               SCA Proceedings, Volume 30 (2016)                            Bryne, Gandy, Robinson, and Johnson p. 219
   2   3   4   5   6   7   8   9   10   11