Given that it's scanning the duty cycle as seen by any part of the eye is very small. If the perceived brightness was a function of power density averaged over time, then it would very obviously have to be able to be much brighter than "full white" to create the full white experience[^].
[^] in reality the perceived brightness is somewhat higher than the mean (i.e. a light source that's twice as bright with twice smaller duty cycle appears brighter). I'm not sure how large an effect that is, and whether it has anything to do with pupil size adjustment.
[^] in reality the perceived brightness is somewhat higher than the mean (i.e. a light source that's twice as bright with twice smaller duty cycle appears brighter). I'm not sure how large an effect that is, and whether it has anything to do with pupil size adjustment.