Reflection electron microscopy (REM) allows a very accurate determinat
ion of crystallographic directions on a surface. The lack of resolutio
n in REM due to foreshortening is compensated by enhanced sensitivity
for measuring angular differences of these directions. This is shown b
y sequences of atomic steps on Pt(100). The lattice of reconstruction
on (100) and (111) surfaces of gold could directly be imaged with a se
paration of approximately 4.0 nm and 6.7 nm, respectively.