Honestly, I see no reason to own this lens. I've used it and it's slow to focus, loud, only 2.8 and the IQ is just okay. There are so many zooms that overlap this, and unless there's a real, quantifiable reason to own a prime, you're wasting your money. Pretty much my rule of thumb is, if you're happy with 2.8, get a zoom, if you want to do better, get a high quality prime. This lens failed on both counts. This is the lens you buy because it's cheap, then it sits in the bottom of your camera bag for 5 years collecting dust.