Absolute magnitudes for late-type dwarf stars for Sloan photometry
  We present a new formula for absolute magnitude determination for late-type dwarf stars as a function of (g-r) and (r-i) for Sloan photometry. The absolute magnitudes estimated by this approach are brighter than those estimated by colour-magnitude diagrams, and they reduce the luminosity function rather close to the luminosity function of Hipparcos. 
S. Bilir, S. Karaali, S. Tuncel