A new imaging mode, the error signal mode, is introduced to atomic force microscopy. In this mode, the error signal is displayed while imaging in the height mode. The feedback loop serves as a high-pass filter that filters out the low spatial frequency components of the surface, leaving only the high spatial frequency components of the surface to contribute to the error signal and to be displayed. At a scan rate of typically 10 lines per second, images taken in this mode show very fine detail. Since the applied force stays nearly constant, the error signal mode is especially suitable for imaging soft biological samples with a high level of detail without damaging the surface.