Interferometric micrograph of oil aerosol droplets on a glass slide. The micrograph allows to measure the droplet height by counting the number of interference fringes. Each black fringe corressponds to height step of 1/2 wavelength, in this case ~350 nm. The image was acquired using a Nikon 50x DI Mirau-type interferometric objective mounted on Zeiss Axiophot microscope. Incident light used for illumination was filtered using a 650 nm long-pass filter. Scale bar = 10 micrometers. Image by Stanislav Vitha, MIC.