The luminosities of globular clusters are found to correlate with their half-light radii. The most luminous clusters have radii rh∼3. Mean cluster luminosities are <Mv>=-6.64±0.26 for rh<2.O, <Mv>=-7.44±0.20 for 2.0≤rh <4.O pc, and <Mv>=6.57±0.21 for clusters with rh<4.O pc. An even fainter value <Mv>=5.85±0.36 is found for large clusters with rh≥8.O pc. These results possibly weaken confidence in the conclusion that the peak of the globular cluster luminosity distribution is a universal standard candle. in the outer Galactic halo, globular clusters with red horizontal branches are fainter by about a factor of ten than are clusters with blue and intermediate color horizontal branches. Among clusters with RGC>10 kpc there appears to be a clear dichotomy between normal clusters (which all have [Fe/H<-1.2) and the anomalous relatively metal-rich clusters Pal 1, Pal 12, and Ter 7, which are both unusually faint (Mv>-5) and relatively metal-rich ([Fe/H]> -1.0). This suggests that these relatively metal-rich halo clusters may have had an unusual evolutionary history.