We present a critical assessment of commonly used pre-main-sequence isochrones by comparing their predictions to a set of well-calibrated colour–magnitude diagrams of the Pleiades in the wavelength range 0.4–2.5μm. Our analysis shows that for temperatures less than 4000 K, the models systematically overestimate the flux by a factor of 2 at 0.5μm, though this decreases with wavelength, becoming ...
