  An established technique for the measurement of ultra-high-energy-cosmic-rays
is the detection of the fluorescence light induced in the atmosphere of the
Earth, by means of telescopes equipped with photomultiplier tubes. Silicon
photomultipliers (SiPMs) promise an increase in the photon detection efficiency
which outperforms conventional photomultiplier tubes. In combination with their
compact package, a moderate bias voltage of several ten volt and single photon
resolution, the use of SiPMs can improve the energy and spatial resolution of
air fluorescence measurements, and lead to a gain in information on the primary
particle. Though, drawbacks like a high dark-noise-rate and a strong
temperature dependency have to be managed. FAMOUS is a refracting telescope
prototype instrumented with 64 SiPMs of which the main optical element is a
Fresnel lens of 549.7 mm diameter and 502.1 mm focal length. The sensitive area
of the SiPMs is increased by a special light collection system consisting of
Winston cones. The total field of view of the telescope is approximately 12
$^\circ$. The frontend electronics automatically compensates for the
temperature dependency of the SiPMs and will provide trigger information for
the readout. Already for this prototype, the Geant4 detector simulation
indicates full detection efficiency of extensive air showers of
$E=10^{18}\,\text{eV}$ up to a distance of 6 km. We present the first working
version of FAMOUS with a focal plane prototype providing seven active pixels.
