Techniques involving an effect of gravity on gestures are described. The support stand has a first support member and a second support member. One embodiment includes inductive and resistive loads to equalize the gain over the frequency of interest to reduce data-deterministic jitter. The first and second regions can be defined by a single mask, and accordingly can be considered to be self-aligned relative to one another. Multi-junction solar cells have a metal backing layer that secularly reflects the illumination back into an appropriately positioned and aligned camera, selected to be sensitive to infrared wavelengths at which the solar cell materials are relatively transparent.