The completeness estimate of a 6-band multicolor survey covering two UK Schmidt fields is revised using a detailed model for Lyman line effect and continuum absorption and considering the effects of quasar variability. Variability was found to be a significant factor and may demand more sophisticated treatment. Space densities were computed over a redshift range of 2.2 to 4.5.
Results indicate a limit to the decline in space density.
An analysis of the luminosity function over the 2.2 to 4.5 range is presented, based on revised detection probabilities.