2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/205623We extend next-to-leading logarithmic threshold and joint resummation for prompt photon production to include leading collinear effects. The impact of these effects is assessed for both fixed-target and collider kinematics. We find them in general to be small, but noticeable.14 pages, 12 figures, added comment on fragmentation contribution and one more reference. Version to appear in Phys. Rev. DHigh Energy Physics - Phenomenologytext