16:10 is not natively supported, as yet. Only 16:9 is supported natively currently. 16:10 support should be coming in one of the early updates however. Until then, you'll have to live with the Black Bars. It's one of my gripes with the game currently, but it isn't going to stop me enjoying the game. In fact, probably, when 16:10 native support is implemented, I'll probably be so used to playing with the bars that it'll feel strange when I switch.