TalenLenses: Prime and zoom lenses
Today, most lenses sold are zooms. It is easy to see why. Zoom lenses are convenient and most cover a range of focal lengths that would require three or more prime lenses. Why carry three lenses when you only need carry one? Why keep changing from one prime lens to another when you can obtain the same effect by turning a ring on a zoom lens?
In particular, zoom lenses are favoured by news and sports photographers. Often, there is no time to change lenses to capture a decisive moment. A zoom lens can handle near and far subjects simply by turning the zoom ring.
So why would you consider a fixed focal length prime lens? There are three reasons: performance, aperture and focal length.
As a general rule, you can expect better performance from a prime lens than a zoom lens. This is partly because the design and construction of a prime lens is less complex. Although the performance of zoom lenses has improved significantly in recent years, if you are looking for the ultimate in image quality, you need to be using a prime lens.
However, the main reason photographers choose these lenses is their ability to capture pictures in low light. The EF300mm f/2.8L IS II USM is a favourite among sport and wildlife photographers who have to contend not only with poor light, but also moving subjects. In these circumstances, the difference between an f/4 lens and an f/2.8 lens can mean the difference between an award-winning picture and no picture at all.
Performance and aperture are why telephoto wide-aperture prime lenses cost a lot more than a zoom lens that includes the same focal length.
Finally, prime lenses are the only choice for full-frame cameras if you want extremes of focal length. 14mm and 600mm are available as prime lens focal lengths, but are not in the zoom range of any lens.
Most photographers have a mix of zoom and prime lenses, choosing whichever suits the different requirements of their work.
