We recommend downloading the entire image set in TIFF format by following one of the links below. To decompress the files, use "unzip" on Unix or Linux, Winzip on a PC, or a recent version of StuffIt Expander on a Mac.
Download color TIFF images
Download gray-scale TIFF images
Photographs were captured in uncompressed, 8-bit-per-channel format by Mark Talusan and Rebecca Loh using a Nikon D1 digital camera. These are not high dynamic range images, nor are they linearized (i.e., pixel values are a nonlinear function of radiance). We placed each of 10 spheres (Christmas ornaments, some painted) in the same 7 physical locations, and photographed each from a fixed camera. In each location, the camera was positioned at a 45 degree angle from the horizontal with respect to the sphere. The distance from the camera to the spheres was much larger than the diameter of the spheres, so the camera projection is approximately orthographic. The TIFF images have been downsampled by a factor of two in each direction, and the jpegs displayed on the previous page by a factor of four in each direction.
The "desklamp" illumination was the only one created specifically for the photographs. That is, we intentionally positioned a desk lamp above the spheres to obtain a single bright light source.
The "red" spheres (the last in each row on the previous page) were omitted from the analysis of the paper referenced above, because when viewed in gray scale they have optical reflectance properties very similar to the chrome spheres.
View color images
View gray scale images