Do prime lenses have advantages over zoom lenses even today?
In short, yes! Because the focus ring does not need to search as far a distance to find focus since only one focal length is available on prime lenses, prime lenses always focus faster than their zoom lens counterparts if all else is equal.
Are prime lenses sharper than zooms?
In my experience, the answer is yes; however, not by the margin that many photographers make it out to be. Prime lenses are generally much sharper than cheap zoom lenses (under £500), but many of the pro level zoom lenses are on the same level as the prime lenses.
Also, keep in mind that even a prime lens will not produce sharp images if it is made cheaply. I often hear photographers comment on how sharp the Nikon 50mm f/1.8 lens is, but I have personally never found that lens to be anything more than acceptably sharp. Many photographers hear that “prime lenses are sharper” and somehow expect that to mean that ALL prime lenses are sharp, and that simply isn’t true.
When to choose prime, and when to choose zoom
When it comes down to which lens to buy, the fact is that it depends greatly on the lens. For example, I would ALWAYS recommend that a beginning photographer purchase a 50mm f/1.8 lens but in my opinion that lens cannot approach the optical quality of the Nikon 24-70mm lens however, the 24-70 is significantly more expensive.
If a photographer is interested in a super-telephoto lens for sports or wildlife photography, almost any professional photographer would prefer a prime super-telephoto to a zoom super-telephoto for the advantage of faster focusing, slightly sharper images, and the ability to achieve lower apertures.
When it comes to the prime vs. zoom lens debate, the real answer is that it depends on the lens. The purpose of this is to bring to your attention the advantages and disadvantages of zooms and prime lenses, and to point out that the simplistic “primes are better” mentality is simply outdated and overly simplistic.