I'll throw in a second opinion here. I owned the 85 f/1.8 for a brief time, but ended up selling it on ebay. It was a great lens, very sharp. So why did I sell it? It didn't fit my shooting style. I wanted to use the lens indoors and utilize it's wide aperture, but it was simply too long on my 1.6x crop sensor. After the sale I bought the 17-55 f/2.8 IS and came to appreciate the wonderful versatility of a zoom. I later purchased a 70-200 f/2.8 L IS for use outdoors and at weddings. Again, the versatility of the zoom was key.


Only recently have I purchased another prime lens--the 50 f/1.4. Is it a better lens than the 85 f/1.8? Nope. But it fits my needs better. A couple of years ago I wanted a lens that I could take indoor photojournalistic-type portraits. The shorter focal length makes it much more useful to me than the 85mm lens.


The 85 f/1.8 may be a perfect nature lens, but most of the time people want even longer focal lengths for that purpose. It's a great portrait lens, but you need substantial distance for any full-length body shots. Just make sure you know exactly how you want to use the lens so that you make the right choice the first time (unlike me).


As I said, the 85 f/1.8 is a fantastic lens (especially for the money), but it didn't fit me as well as the 50 f/1.4.