Nat. Methods 11, 338–346 (2014); published online 9 February 2014; corrected after print 28 August 2014

In the version of this article initially published, the Drosophila transgenic strains were incorrectly reported as generated using Chrimson (Fig. 3, Supplementary Figs. 14–16 and Supplementary Videos 2–6). Owing to a miscommunication, the Drosophila strains were actually generated with CsChrimson, a CsChR-Chrimson chimera replacing the Chrimson N terminus with the CsChR N terminus. CsChrimson has the same spectral and kinetic properties as Chrimson; these data have been added to the paper in the form of an addendum, and incorrectly listed strains have been fixed in the main text and supplementary materials. The error has been corrected in the HTML and PDF versions of the article.