This article [ J. Biomed. Opt. 12, 060504 (2007)] was originally published online on 18 December 2007 with an error on page 2, line 19. The text “…the $455\text{‐}\mathrm{nm}$ detector to that of the $525\text{‐}\mathrm{nm}$ detector…” should read “…the $525\text{‐}\mathrm{nm}$ detector to that of the $455\text{‐}\mathrm{nm}$ detector….”

All online versions of the article were corrected on 29 February 2008.