  We analyse the structural and dynamical properties of a sample of 324 nearby
elliptical and dwarf elliptical galaxies observed during an extensive NIR
survey in H-band (1.65 micron). The Fundamental Plane (FP) is determined and a
significant tilt is assessed. The origins of such a tilt are investigated by
means of a spherically symmetric, isotropic pressure supported dynamical model
relying on the observed surface brightness profiles. The systematic variation
of the shape coefficient converting the measured central velocity dispersion $
sigma_0$ into the virial rms velocity $ sigma_{rms}$ is found to be the main
cause of the tilt, due to aperture effects. Moreover the ratio between the
dynamical mass $M_{dyn}$ and the total H-band luminosity $L_H$ turns out to be
roughly constant along the luminosity sequence of ellipticals: H-band
luminosity is therefore a reliable and cheap estimator of the dynamical mass of
the Es.
