Use of low accelerating voltages (e.g. 1-2 kV) can provide particular advantages over more conventional (10-30 kV) potentials for HR imaging. The lower energy of the electrons means that the electron path in the sample is reduced, as is secondary electron escape or breakthrough from sharp edges. These factors (for instance) allow more faithful surface representation of materials or nanostructures made from light elements, such as carbon nanotubes. Fine surface features can be more accurately delineated, and the dynamic range of the video signal is lowered, potentially reducing problematic, strong image contrast. Finally, low-kV SEM can sometimes allow imaging of insulating samples without first coating the samples with conductive (e.g. metal) coatings that can deleteriously modify surface morphology.