We present here a new experimental tool for the direct observation of magne
tic vortices in type-II superconductors. The magneto-optical imaging techni
que has been improved to enable single vortex observation at low flux densi
ties. The main advantage of the new method is its high temporal resolution
combined with the applicability to any superconducting sample with a flat s
urface. We give a short description of the experimental set-up and show exa
mples of results obtained for a NbSe2 single crystal at 4.0 K.