Shadow measurement techniques require a good illumination source to obtain high quality images. The use of very short pulses of light enable particle motion to be frozen, thus ensuring good image contrast. Lasers offer the shortest pulses but require the use of special optics to enhance light distribution. The ShadowStrobe is an illumination unit to be used with a laser. The optics allow the size of the illuminated area to be adjusted to match the camera’s field of view and thus benefit from the full light energy.