In this video we use two different techniques to visualise transparent silicone oil droplets. Shadowgraphy is used to visualise the full droplets spreading, in the milimeter scale. On the other hand, laser interference is used to visualize the spreading of the droplets in the micrometer scale.
In the experiments, small amounts of high viscosity (5CST) silicone oils were added to low viscosity silicone oils (0.65cst). The spreading of the droplets exhibit fingering instabilities whose shape depends on the amount of the high viscosity oil added.