  We present the first high spatial resolution monitoring of the dust forming
nova V1280 Sco performed with the Very Large Telescope Interferometer (VLTI).
Spectra and visibilities were obtained from the onset of the dust formation 23
days after discovery till day 145, using the instruments AMBER and MIDI. These
interferometric observations are complemented by near-infrared data from the
1.2m Mt. Abu Infrared Observatory, India. The observations are first
interpreted with simple models but more complex models, involving a second
shell, are necessary to explain the data obtained from t=110d after outburst.
This behavior is in accordance with the light curve of V1280 Sco which exhibits
a secondary peak around t=106d, followed by a new steep decline, suggesting a
new dust forming event. Spherical dust shell models generated with the DUSTY
code are also used to investigate the parameters of the main dust shell. Using
uniform disk and Gaussian models, these observations allow us to determine an
apparent linear expansion rate for the dust shell of 0.35 +/- 0.03 mas/day and
the approximate time of ejection of the matter in which dust formed as
t_ejec=10.5+/-7d, i.e. close to the maximum brightness. This information,
combined with the expansion velocity of 500+/-100km/s, implies a distance
estimate of 1.6+/-0.4kpc. The dust mass generated was typically 2-8 10^-9 solar
mass per day. Considering that the dust forming event lasted at least 200-250d,
the mass of the ejected material is likely to have exceeded 10^-4 solar mass.
