Backlighting is extensively used as a diagnostic tool in experiments relative to Inertial Confinement Fusion. Thus, beam and target nonuniformities effects on hydrodynamic instabilities growth and imprinting, shock propagation in solid materials and foil acceleration are studied in planar geometry. Spherical or cylindrical implosions measurements are relative to hydrodynamic instabilities, feedthrough and fuel-pusher mixing, in-flight aspect ratio, implosion velocity, symmetry and peak compression densities. With the laser mega-joule very high laser power and energy will be reached that will give access to new density and temperature domains. Correlatively, diagnostics survivability has to be considered taking the large X-ray, neutron and debris emissions into account. The X-ray induced shocks or neutron induced radioactivity will constitute limitations to measurements inside the target chamber. The experimental program on its route towards ignition and gain will anyway still require backlighters to optimize the targets parameters (the microballoon wall thickness, the ablator nature) and allow the adjustment of not well known quantities as opacities and equations of state.