Mixed heliostat field combining, in the same field, heliostats of different sizes and/or with different types of facets, all of them having at least one facet and being canted or not, and either having spherical, cylindrical, flat or quasi-flat (spherical with a high curvature radius) facets, such that the solar field is optimised in order to minimise shadows and blockages between heliostats, as a result of correct positioning of the heliostats in the field.