50mm

Earlier this week Nikon announced the addition of a fourth Nikkor 50mm lens to their lineup in the form of the Nikkor 50mm f/1.8G lens. Nikon’s other three 50’s include the 50mm f/1.4G, the 50mm f/1.8D and the 50mm f/1.4D—prices for each range from $135-$550. So between all the D’s and G’s, how do you know which one is right for you, or better yet, why buy a 50mm lens in the first place?

In 2007, German lensmaker Carl Zeiss branched out from the medium-format lenses it had concentrated on for decades and followed its customers to the digital SLR 35mm platform. Now, four years later, the line spans nine focal lengths from 18mm to 100mm, all primes with manual focus only. The 50mm f/1.4 may be the most interesting. The fastest and lightest of the new breed, it is available in the most mounts and costs the least by far—though still plenty of coin ($725, street).