Fig. 2.

Response of AD10 at OD = 5.3 to a stepped intensity pattern. a Normalised quantities as indicated vs. x after ≈30 min of stepped illumination, and predictions for normalised ρ^s based on two speeds (dotted line) and complete measured $\overline{v}\left(x\right)$ profile (dashed line). Error bars are s.e.m. of the y-averaged values. b Time dependence of normalised ${\rho }^{\mathrm{s}}\overline{v}$ at various x (see legend). The sample was uniformly illuminated before the halves pattern was switched on at $t=0$. In both plots the grey area corresponds to the standard deviation in experimental values for uniform illumination ($t<0$)