The light-scattering characteristics of smectic A liquid crystals are investigated. In the case of an electrooptic effect, the scattering texture is produced through either the field effect or the current effect. It is found that the textures formed due to this effect give rise to diffusive scattering patterns resulting from multiple scattering in the structure. In the case of a thermooptic effect, the scattering texture is obtained through the phase transition from a nematic to a smectic A phase. The textures formed as a result of the thermooptic effect exhibit higher diffraction peaks correlating to the shape of the domains. The scattering characteristics are found to depend on the process which forms the textures.