Before an impacting droplet can contact the surface, it must drain the air beneath it. Theory and experiments have shown that a nm-thin layer of air mediates the contact of droplets on smooth, solid surfaces, particularly at low impact velocities; however, the effect of the air film on the impact process remains unknown. Using a novel TIR technique, we measure the profile of the liquid-air interface during the droplet impact process, varying liquid viscosity and impact velocity. The dynamics of the liquid-air interface demonstrate a general behavior for all liquid viscosities and all impact velocities, and suggest that the interaction between the air and liquid is more complicated than was previously thought; furthermore, this general behavior could play a role in droplet impact dynamics at high impact velocities, and even affect the splashing of viscous liquid droplets on surfaces.