  Using imaging data from the SDSS survey, we present the g' and r' radial
stellar light distribution of a complete sample of ~90 face-on to intermediate
inclined, nearby, late-type (Sb-Sdm) spiral galaxies. The surface brightness
profiles are reliable (1sigma uncertainty less than 0.2 mag) down to
mu=~27magsqarcsec. Only ~10% of all galaxies have a normal/standard purely
exponential disk down to our noise limit.
  The surface brightness distribution of the rest of the galaxies is better
described as a broken exponential. About 60% of the galaxies have a break in
the exponential profile between ~1.5-4.5 times the scalelength followed by a
downbending, steeper outer region. Another ~30% shows also a clear break
between ~4.0-6.0 times the scalelength but followed by an upbending, shallower
outer region. A few galaxies have even a more complex surface brightness
distribution.
  The shape of the profiles correlates with Hubble type. Downbending breaks are
more frequent in later Hubble types while the fraction of upbending breaks
rises towards earlier types. No clear relation is found between the
environment, as characterised by the number of neighbours, and the shape of the
profiles of the galaxies.
