I'm sure there are plenty of these types of threads and maybe even some with the specific question I'm asking, but here goes:
I'm just understanding the importance of full-frame and crop sensors. I currently have a T2i and my lens collection includes the kit lens, a nifty fifty, and a 70-200 f/4L. My question is: Is it pointless for me to get the 85mm f/1.8? I am very heavily into portraiture and I've read it's amongst the best lenses for that, but what confuses me is that I've read on this forum statements like "you already have that length covered" or something of that sort.
Fill me in all mighty forum members! A good explanation will decide my next purchase so feel free to suggest something I should need as a portrait photographer!