Excerpt: I bought this lens to be shared by my both my wife and me. She shoots a D5000 with a primary interest in portraits and I shoot a D750 with an interest in landscapes. It functions as a perfect lens for my wife with the DX crop taken into account it functions like a 75mm lens.
Summary: Great lens. Everyone has been telling me I need a prime lens since I bought my DSLR camera and they were right. Really changes the quality of pictures and really just the way I am thinking about composition. Step up from the kit lenses that came with my camera.
Excerpt: I use this lens when I need to take pictures indoors, particularly in settings where flash is not allowed (i.e. museums, churches). If you think a f/2.8 "professional" lens can do low-light well, then this lens is an eye-opener.