A device and a method for acquiring a microscopic image of a sample structure are described. An optic for imaging the sample structure and a reference structure is provided, as well as a drift sensing unit for sensing a drift of the sample structure relative to the optic on the basis of the imaged reference structure. The optic comprises a first sharpness plane for imaging the sample structure and at the same time a second sharpness plane, modifiable in location relative to the first sharpness plane, for imaging the reference structure.