Fossil Balaenopterid Whale from the Miocene of Orange County, Southern California.

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Fossil Balaenopterid Whale Emerges from the Miocene Capistrano Formation in Laguna Niguel, Orange County, Southern California. Captured through photogrammetry and mesh constructed using Agisoft Photoscan Professional Edition. Digitized by Steve Clawson and Gabriel Santos. Many thanks to Ralph C. Clark Regional Park for access to the skeleton. Print Settings Printer Brand: Up! Printer: Up Mini Rafts: Yes Supports: Yes Resolution: 200 µm Infill: Loose Honeycomb How I Designed This Photographs of the specimen were taken within the Clark Regional Park collections with a Nikon D3000 SLR camera, maintaining an 18-mm focal length. Single lens reflex cameras are ideal for photogrammetry due to their ability to efficiently compensate between changing lighting conditions over the course of an afternoon (Coe et al., 2010). Windows in the facility were covered with black garbage bags to minimize such lighting effects. Three rounds of center-facing photography were necessary to produce a photogrammetric map of the specimen: 90° (vertical), 45° (intermediate), and 0° (horizontal), performed in a circular pattern around the specimen. Capture reference points were demarcated using standardized United States Bureau of Land Management (BLM) scale bars. Vertical shots were taken using a boom monopod to tightly mount the camera 50 inches above the lowermost point of the specimen. Due to a geometric relationship between sensor height and lens focal length, many photographs were taken at 90° orientations, producing shot dimensions in this case of ~1.7 m x 1 m (Fig. 1) (Birch et al., 2006). This required moving the monopod every 50 cm N/S, and every 35 cm E/W. Shots at 5° were taken using a tripod to mount the camera 50 inches above the specimen. While 2/3 overlap is still necessary for these photographs, the larger dimensions of each shot (2 m x 1.5 m) translated to taking fewer photographs, requiring the tripod to be moved every 90 cm N/S and 75 cm E/W. Horizontal shots required the camera to be placed by hand close to the surface of the specimen. The dimensions of each shot therefore vary, though camera positions were ~50 cm apart for each shot. The resulting photographs were imported in succession into Agisoft Photoscan Professional Edition, Version 0.9.0, an image-based 3D modeling/photogrammetric software package that works with a number of formats (e.g., JPEG, TIFF).