Although there were a few bumps in getting pbrt to work, those were quickly fixed. I used cygwin and Microsoft Visual Studio 2003, using a plug-in to view the exr files in Adobe Photoshop. Mimicking the shadows was time-consuming, and I looked a lot at positioning, including lights that I saw against the backdrop, and shadow softness to evaluate where and what type of light should be used. Although the first one or two faces were relatively easy to understand in terms of coordinate systems, on the third and fourth I started looking more in depth into the general rules of the axes, orientation, and such. I rendered images more quickly by breaking down the lights one at a time and by rendering in lower resolution with fewer samples per pixel, as recommended.