A device, a method and a system for optically determining particle properties, in particular size and reflectivity. The device includes at least one light source assembly having at least one light source, a polarizer assembly, at least one sample holder—which can be illuminated by the least one light source assembly—for accommodating particle preparations to be investigated, at least one analyzer assembly, and at least one imaging device with at least one color-resolving matrix image sensor. The device is designed to guide light reflected by a particle preparation and having a color-coded polarization to the at least one matrix image sensor.