Originally Posted by nycme
I feel so awful. I wonder if using a light during the daytime would make a difference in situations like this.
If the sun was behind him then I think a light would actually produce the opposite effect of reducing his silhouette thus making him even more difficult to see. The effect was demonstrated during WW2 in an experimental project called Yehudi which focused on mounting lights on the the body and wings of divebombers to give them extra time when diving out of the sun to hit subs who were at the time able to submerge quicker than the attackers could mount an effective attack. The lights would help to mask their visual presence and thus reduce the detection range/time for the sub crew to react. Similar experiments were conducted decades later during the 1960s in a project called Compass Ghost to try and reduce the silhouette of the large F4 Phantom by strategically placing lights on it. The study found that they could reduce the detection range by as much as 30%. At one time, during the Have Blue project which was the project that led to the development of the F117 Nighthawk stealth fighter, an active lighting scheme was also planned. Everytime people talk about DRLs and using lights to increase their visibility, I have to point out that what you're trying to achieve is contrast and silhouette enhancement. Casting light may not always achieve this goal.