  To investigate the interplay between microscopic dynamics and macroscopic
rheology in soft matter, we couple a stress-controlled-rheometer equipped with
a Couette cell to a light scattering setup in the imaging geometry, which
allows us to measure both the deformation field and the microscopic dynamics.
To validate our setup, we test two model systems. For an elastic solid sample,
we recover the expected deformation field within 1 micron. For a pure viscous
fluid seeded with tracer particles, we measure the velocity profile and the
dynamics of the tracers, both during shear and at rest. The velocity profile is
acquired over a gap of 5 mm with a temporal and spatial resolution of 1 s and
100 microns, respectively. At rest, the tracer dynamics have the expected
diffusive behavior. Under shear, the microscopic dynamics corrected for the
average drift due to solid rotation scale with the local shear rate,
demonstrating that our setup captures correctly the relative motion of the
tracers due to the affine deformation.
