looking for a lens to help shoot high school cheerleading

[Jptex]

I have the D7100 and a 16-85mm lens and the 85mm f1.8 lens. I was volunteered (or volun-told by my wife :mrgreen to be the JV high school cheerleader photographer on game nights and events. This will give me access on the field and closer up shots. I was thinking of getting the Sigma 17-50 mm F2.8 since this will be a faster lens for the darker environment. I will keep the 16-85 lens for a walk around lens. Since, I will only be focusing on the cheerleaders I wouldn't need a longer lens. Any suggestions on this lens or a different one?

Thanks
Jason

 

[tirediron]

Since you've been voluntold, I would make sure that your wife is aware that it is absolutely impossible for you to do this properly without at least the 17-50 and the 70-200! The 17-50 is a well regarded lens, and an excellent lens on DX bodies, BUT it is a little shorter than I prefer for portrait work, so if you're doing single-person shots of the cheerleaders, then consider using your 85 prime.

 

[Jptex]

That was my thought. I was looking at this lens so I can get the wider angle and catch the whole team. I will be around 10 to 20 feet away at any giving time. So I should be okay at 50 mm max. If not I will take a step back and use my 85 prime.