We’ve been in the backcountry for a few days, but now we’re camping near the N7 highway with a cellphone tower in sight. We’ve gotten our routines running, and have managed to process two populations on the best days. Today our luck was worse – our work at the first Lithops marmorata site in the morning was cut short by rain, and in the afternoon a thunderstorm developed right when we were imaging another population.

Below are a couple of pics of our photographic arsenal. At each location we aim to measure 10-20 individual Lithops plants and the soil on which they grow. To get a detailed view of the spectral properties of the plants, we use a Surface Optics SOC710-VP hyperspectral imager. The hyperspec camera records reflectances at 128 wavelenght bands between c. 400 and 1000 nm. Note that there is actually a Lithops plant right below the camera in this photo.

The same individual plants are also photographed using a Nikon D7100 DSLR camera that has been modified so that it records both visible and ultraviolet (UV) light. In this case, we take two images, one using a UV-blocking filter (so that we get standard visible-light RGB images) and one using a filter that blocks visible light (so that we get a UV picture using two of the sensors). The filters are changed between the shots using a slider rig that is a variant of Jolyon Troscianko’s model (see www.jolyon.co.uk). The slider and the two filters are visible in front of the lens in the photo below.