  In this work we present detailed photometric results of the trapezium like
galactic nearby OB clusters NGC 1502 and NGC 2169 carried out at the University
Observatory Jena. We determined absolute $BVRI$ magnitudes of the mostly
resolved components using Landolt standard stars. This multi colour photometry
enables us to estimate spectral type and absorption as well as the masses of
the components, which were not available for most of the cluster members in the
literature so far, using models of stellar evolution. Furthermore, we
investigated the optical spectrum of the components ADS 2984A and SZ Cam of the
sextuple system in NGC 1502. Our spectra clearly confirm the multiplicity of
these components, which is the first investigation of this kind at the
University Observatory Jena.
