If realism is so important to you, and you're dealing with comics, shouldn't the functionality of capes be the last thing on your list of priorities?

In my dream, the world had suffered a terrible disaster. A black haze shut out the sun, and the darkness was alive with the moans and screams of wounded people. Suddenly, a small light glowed. A candle flickered into life, symbol of hope for millions. A single tiny candle, shining in the ugly dark. I laughed, and blew it out. - Joker