The appearance of the λ ring changed dramatically when it was observed in forward-scattered light in 1986. In this geometry the ring became the brightest feature of the Uranian ring system, outshining the ε ring. This observation, together with the wavelength dependence of the optical depth, indicates that the λ ring contains significant amount of micrometre-sized dust. The normal optical depth of this dust is 10−4–10−3. Observations in 2007 by the Keck telescope during the ring plane-crossing event confirmed this conclusion, because the λ ring became one of the brightest features in the Uranian ring system.