Extended Data Fig. 10: Extended depth of focus vs projection method.

a Schematic representation of an imaging volume of height Z, imaged with an extended depth of focus (EDF) PSF. The EDF PSF is n-fold extended in the axial direction. b Imaging the same volume while rapidly sweeping a diffraction limited PSF and a light-sheet through the same volume. Since the PSF in (a) is n-fold stretched compared to the diffraction limited PSF in b, the Strehl ratio (that is the peak intensity of the PSF) is at least n-fold reduced compared to b. For a, the whole sample is illuminated during the exposure time. In b, any part of the sample is illuminated 1/n-th of the exposure time. Assuming linear fluorescence response to excitation light-intensity, the lower Strehl ratio of the EDF PSF is compensated by the longer effective exposure time of any part of the sample.