Yet another question people always ask me. I’m going to try and simplify this as much as possible. First, if you are like most people you’ll assume that having a range of focal lengths for framing is more valuable. This couldn’t be farther from the truth. I call zoom lenses “lazy lenses” because people tend to stand in one spot and just take the same pictures over and over again, changing the zoom as if its going to make the picture better. Consequently this is why people tend to not like prime lenses, because they have to move around to get a shot. Treat it as if your playing tennis. You have to move your feet if your going to hit the ball with any accuracy. So now that you are not going to join the lazy zoom lens crowd, lets examine the prime lens range!
They are broken up into 2 categories, wide angle and zoom. technically speaking the 50mm is neither as it is considered to be a human eye equivalent. So well start from the bottom.
Wide angle (8-50mm) – These can paint an entire environment when used properly. They will be more effective when your subject is close up for a portrait, and great for landscapes and negative space when used far away. The blur effect falls off quickly with these so if you want a blurry background, then keep your subjects close! example : 16mm f2.8
Next we have the zoom range (50-200+mm) – These are great for portraits, they can also be great for stitching images together to create unusually well cropped images of large subjects. But for the most part just think of, capturing a single subject where the background is not as important. Example: 50mm f1.8
Hopefully that helps simplify your decision making! Happy shooting!