Figure 12: Picture at 950 nm (filter) showing the settling interface zone of the STEP0. It appears clearly that the aura is more transparent than the supernatant. (Notes: Camera Nikon D70; objective: 40-40 mm f/2.8-2.8; focal length 40 mm; pause time: 1/320; the violet color of the initial photo was changed to black and white artificially (software); tube diameter: 1 cm).