Simply put a prime lens is a lens that has a single focal length. This means you can’t zoom with the lens. This is in contrast too a zoom lens, which can be zoomed across a range of focal lengths.
Why use a prime lens?
You might be asking, why use a prime lens instead of a zoom lens? Afterall a zoom lens is more convenient. Well, this can be a sensitive subject in photography circles. Objectively prime lenses are generally cheaper at comparable specs, generally better quality optically, generally have larger maximum apertures, and are generally smaller and lighter than a comparable zoom.
For instance, I have a Sigma 85mm f1.4 prime lens, and I also have a Tamron 70-200mm f2.8 zoom. While it is nice to have the zoom range of the Tamron it is also bigger, heavier, and has a much smaller maximum aperture. The Sigma 85mm f1.4 is also one of the sharpest lenses ever made, it’s a step above any zoom lens in that regard.
So objectively there are advantages to a prime lens, but are there other reasons to use a prime lens?
Getting the perfect look.
One major reason to use a prime lens is understanding the optical properties of the lens innately. When you shoot with a prime you really train yourself to know where to place your subject and where to stand in relation as well as what aperture to use to have proper focus and separation with the background. When it comes to getting a certain look over and over you could argue that it’s easier to use a prime lens because it reduces some of the variables you have to consider.
Prime lenses have a unique quality, they’re usually made with a faster maximum aperture than a zoom. This not only gives you more light to work with, it also improves the quality of bokeh. So if you want to have total control of background separation in all situations the prime is the winner hands down.
Zooms have their place, they’re convenient, and they’re actually quite good these days. But for the ultimate in performance at a certain focal length choose a prime lens.
Which do you prefer, zooms or primes? Let us know in the comments.