We study the metal-rich bulge globular cluster Terzan 5 by means of VI colour-magnitude diagrams, with images obtained under exceptional seeing conditions (0.34"-0.50"). Differential reddening is important across the cluster. We derive a reddening of E(B-V)=2.49 and a distance from the Sun d_{sun}_=5.6kpc, closer than previous estimates. Based on the red giant branch curvature, we derive a metallicity somewhat higher than that of NGC 6553, probably solar.