This contribution stresses the importance of video microscopy for the deter
mination of the structure and dynamics of colloidal dispersions. As soon as
the spacial resolution of optical microscopy is high enough, this method c
an be adapted to determine the pair potential U(r) and the diffusion coeffi
cients D of colloidal dispersions. (C) 1998 Elsevier Science B.V. All right
s reserved.