Hertzsprung-Russell diagram of the DIANA sample (orange markers) and all stars in the original single zone grid (blue) and the adjusted grid (green). The grey lines are the evolutionary tracks from (Siess et al. 2000) for different masses, and the coloured dashed lines are isochrones. The histograms show the distribution of values for luminosity and temperature for the sample and the grid in the same colours as used in the main plot. The sample's histogram is scaled to make a comparison easier.