We report on ellipsometric measurements on freely suspended liquid-crystal films of two compounds possessing smectic-A and ferroelectric smectic-C phases. One of the compounds shows in addition an antiferroelectric smectic-C-A phase. The comparison of the surface-induced order near the smectic-A to smectic-C transition indicates that the latter compound shows a considerably reduced coupling of the molecular tilt in neighbouring layers possessing the same tilt directions.