The study of high redshift galaxies provides important clues about the initial phases of galaxy formation and assembly. Focusing in the optical, colour-colour diagrams are used to define Lyman break galaxies at z > 2.5 (LBGs; e.g. Steidel+96, McLure+06, Bouwens+15), and narrow-band imaging to define Lyα emitters (LAEs; e.g. Ouchi+08). Using ALHAMBRA data, Viironen+15 demonstrate that PDF techniques yield reliable number counts of 2 < z < 5 galaxies without performing neither a colour-colour pre-selection nor a completeness/contamination correction from simulations. The PROFUSE techniques will be applied to derive the UV luminosity function, φ(z,M_UV).

PHASE: Development phase.