The combination of words for today, contrast and master, took my head straight to a chess board.  There is the obvious contrast between the black and white of the board and also the pieces.  There is also the contrast that comes when one masters the game and defeats an opponent.

Master also makes me think of artists and the many different ways that they use the notion of contrast in making art - light and dark, hard and soft, warm and cold, and so on.

Do you consider yourself a master of something?  A game?  An art form?  A sport?  A hobby?  If so, photograph it today.  

Maybe you want to be a master of thinking outside the box by putting your personal twist on what contrast means.  Whatever you choose to do, have fun!