In the almost distant past, the prime lens was de rigueur. Just about every SLR from the late 1930s up until the mid-1970s was equipped with a 50mm prime lens. Then manufacturers started to include zoom lenses as part of the kit because it afforded entry-level photographers more bang for the buck.
These early zoom lenses were slow and of relatively poor quality (this created a stigma for zoom lenses that still lingers to this day, even though some of today's zoom lenses are the sharpest ever manufactured). As time went on, zoom lenses got better in quality and speed, and many pros shifted to high-end zooms for most work, keeping around a few primes mostly for dedicated applications such as macro, portraits, architecture or other specialized areas of photography.
Today, there's a resurgence in the popularity of prime lenses. The ultra-high resolution of the current generation of DSLR cameras demands the highest-quality glass to take full advantage of their potential—and current prime lenses are sharper than ever. They're also useful for video work.
Primes are attractive not just for their sharpness, but also for their wide maximum apertures. A wide aperture allows you to shoot in lower light using faster shutter speeds or lower ISO settings. Plus, wide apertures create a shallow depth of field for subject isolation and for selective focus that draws the eye to the sharpest part of the image.
Just about every prime lens has a fast aperture. Most primes start out with the relatively inexpensive ƒ/2.8 to ƒ/1.8 lenses, and then you step up to the ƒ/1.4 lenses, which are substantially more expensive and marketed mostly as pro lenses. Up from there, we have some specialty lenses with apertures of ƒ/1.2.
PUTTING TOGETHER A KIT
If you're serious about shooting primes, put together a good kit. Every photographer has his or her own preferences; the way you compose your images and your typical subject matter are huge factors in the lens selection process. For our purpose here, we'll put together a basic kit that will cover most bases.
Tip: When considering which prime lenses to buy, research your photo metadata and determine which focal lengths you use most on your zoom lenses.
A basic prime lens kit should have at least three lenses: one wide-angle, one standard focal length and one telephoto. For general purpose or portrait photography, I recommend a moderately wide lens, a normal lens and a short telephoto lens, such as a 35mm, 50mm, 85mm combo. A landscape shooter might want to explore more extreme wide-angle options, whereas someone who shoots a lot of wildlife, sports or action will want to look for a longer option in the telephoto area.