Fig. 4. Summary of contrast-response relation under several conditions showing that the contrast ramp method estimates contrast sensitivity similarly to the contrast step method, but much more quickly. Data analyzed as in Fig. 3C. All parameters as listed, spatial frequency= 0.1 cycles deg.^-1. (A-E) Data from two HSNE cells from several retinal locations. (F) HSN cell from Fig. 3 viewing laterally positioned grating. All data from male flies. Values are means ± instantaneous s.d. from a minimum of 3 trials. Az, azimuth; El, elevation.