Just thought I would bring this up again in light of recent pics of nocturnal birds being flashed at night.The following is about the most favorable article I can find but even it says eyesight very reduced for 10-15 minutes where full function takes 1 hr.Using the excuse that their hearing can compensate just does not wash with me.Why even take the chance this bird can be harmed by predators or hurt itself.I would think it needs at night it's full senses at all times.I personally would find it scary to have reduced eyesight for any period of time just for the sake of a picture.
Flash as main light in dim light conditions can produce a temporary reduction in vision but not permanent damage.
In total darkness, use of flash may cause a temporary reduction in vision for 5-20 minutes. It takes one hour of dark conditioning to achieve maximum electrical responses from rod cells in the retina. The regeneration of rod function even after "bleaching" by a bright light is not linear with time. Animals and birds probably have 50% return of function in the first five minutes, and 75% in another five minutes. The rods are rapidly moving from zero function to full sensitivity during that time, with the greatest return of function per time unit occurring in the first 10-15 minutes.
Because of the initial impairment of vision from flash in total darkness, repeated flash of birds or animals in this situation is not advocated. Ethical nature photographers avoid altering their subject’s behavior. The judicious use of flash in completely dark situations causing a brief vision alteration must be offset by the educational value of the photograph made. Technically excellent pictures of owls and other animals in their natural environment made at night with flash may, in the end, benefit the species as a result of increased public awareness. In select situations, the use of flash may be justified. Many nocturnal species rely upon other senses in combination with vision during dim or dark conditions; for example, the auditory capabilities of owls at night are probably far more important for hunting as compared with the visual sense.
Thanks Ted Ardley
Isn't this part of the article i posted above a while back that no one bothered to comment on?