An image sensor includes a pixel array having a plurality of pixels. The transparent emulsions of the present invention comprise an oil phase, containing at least one lipophilic solvent; an aqueous phase; and an emulsifying system containing at least one non-ethoxylated fatty acid ester emulsifier having a hydrophilic-lipophilic balance from about 11 to about 16. The system emits microwaves rearwardly of the vehicle and senses microwave reflected from objects behind the vehicle.