When deciding what’s the best glass to fit on the front of your camera, one of the main debates is always between prime and zoom lenses. Many times the debate centers around a quality issue. There may be other features to argue upon such as image stabilization, autofocus/manual focus, the different ways you use a prime lens compared to a zoom, but traditionally primes were always seen as better quality than zoom lenses.
This made sense with lenses a few decades old. However, zoom lens technology has come a long way and some can equal or surpass the quality of a prime lens. In this article we will go over what makes up each type of lens and the pros and cons of each. Like any question in the photography world if asked which type of lens is best, the answer is usually, ‘it depends on what you want to use it for.’
Apparently, the word ‘prime’ originally comes from the ‘cine’ world where they used a primary lens on a multi-lens system. A prime lens has a fixed focal length, i.e. no zoom abilities. If you want to get nearer of further from your subject, you have to physically move. More or less how most smart phone cameras work.
Prime lenses are usually quite compact compared to a zoom lens, can be produced for a high-quality to cost and can feature a wider aperture than a zoom lens, e.g. f/1.8 or f/1.4 to let in more light and get a smaller depth of field/bokeh/background blur. For example a Canon 50mm f/1.8.
A zoom lens can change its focal length to can get nearer or further from a subject while standing in the same spot. Turn the zoom ring on the lens and you have a wide range of focal lengths from wide angle to telephoto. Like having a bunch of prime lenses in one lens design.
Every zoom lens has a zoom range usually quoted in millimetres, e.g. 24-70mm and 70-200mm. The lower the first number the more wide-angle the view, the higher the second number the more telephoto or zoomed in the subject. The aperture is also variable and may work differently depending on if it’s a consumer or pro level zoom lens. A 18-55mm consumer zoom lens with an aperture range of f/3.5-f/5.6, will have an aperture of f/3.5 at 18mm and f/5.6 at 55mm. Pro level zoom lenses usually have one maximum aperture throughout the focal range, e.g. f/4 or f/2.8.
Zoom lenses are also usually physically bigger than prime lenses and feature more glass and elements internally to cope with the changing focal lengths. These are the basic differences between the two types of lenses and now we will look at the advantages and disadvantages of both.
Prime Lenses Advantages
If you can zero in on the focal lengths you use the most, a prime lens can be more cost-effective. Zooms usually cost more than a single prime lens depending on which lens you buy. It’s an option to buy one or two prime lenses which fit into the focal range of a zoom lens and still have quality images.
Prime lenses are usually smaller and lighter than zooms. This is significant if you are carrying your camera around all day long, such as on a wedding shoot. A Canon 70-200mm f/2.8 with image stabilization weighs in at 3.26 lb/1480g, while a Canon 85mm f/1.4 weighs 950g. The 85mm f/1.4 may have only one fixed focal length, but all things considered it’s not a disadvantage but rather another way of working.
Move. It’s what you will be forced to do from day one of owning a prime lens. Physically having to move nearer or further from a subject is a good way to practice composition, finding different angles and learning a lens. However, there are always shooting situations where you physically cannot move from your spot, so never completely discount a zoom from your lens arsenal.
Prime lenses have the advantage of having a wider aperture. The best zooms ae usually their widest at f/2.8, while some prime lenses can go as wide as f/1.2 or even on some of the latest mirrorless optimised lenses to f/0.9. The lower the f number means the shallower the depth of field/bokeh/background blur and the better they are in low light. If you want the shallowest depth of field possible from a lens, prime lenses may be the way to go. Having such a low f number means you can let in far more light than even the best zoom with an f/2.8 aperture and still get sharp images. Image stabilization helps in low light, but not so good with moving subjects.
Some of the most expensive prime lenses only have manual focus, no advanced autofocus. These lenses are more specialist, towards high-end studio work, architecture and portraits.
Zoom Lenses Advantages
Convenience and versatility are a big advantage of any zoom lens. This doesn’t mean you’ll skimp on image quality these days, but there are always scenarios were you have to stand in one spot and then quickly zoom in and out from wide angle to telephoto to properly frame your subject. Weddings are a great example where you need to be capturing every moment and it’s simply not practical to keep swapping out prime lenses throughout the day, even if you have a few camera bodies at your disposal. You can use the prime lenses for more staged images where you have a little more time.
The convenience of having just one zoom lens instead of a bunch of prime lenses covering the same focal range can’t be ignored. In the old days when zoom lenses were nowhere near the quality they are today, a few primes made sense. These days you can get the same or sometimes better quality with just one zoom lens. Less overall weight to lug around all day.
Image stabilization is a common feature on the latest high-end zoom lenses and also coming commonplace for prime lenses. All brands have their own versions like Canon’s IS, Nikon’s VR, Sigma’s OS and Tamron’s VC. All can give you at least three stops of stabilisation, meaning you can handhold a camera in very low light conditions. Some camera bodies even have built-in stabilization saving the need for having the feature on lens.
A zoom lens will also allow you to practice your photography skills at different focal lengths. How you compose an image in wide-angle compared to telephoto can be completely different, along with different settings. A zoom lens will allow you to compare these instantly.
As stated at the beginning, choosing between a zoom and a prime lens depends on the situation, budget and ultimately there are no clear-cut overall answers. You firstly need to define your shooting needs and then pick the appropriate lenses. If you are a studio photographer, want the very best quality and are familiar with the distances you work, a few top end quality prime lenses will fit the bill. If you are a wedding photographer running around all day, then a 14-24mm, 24-70mm and a 70-200mm zoom lens will cover every conceivable focal length you will ever need. You could possibly just get away with a 24-70mm all day long.
If you are just starting down this journey of interchangeable lenses then a good start point for a prime lens is the 50mm. On a full frame sensor camera body it’s more or less the view we see with our own eyes. At the consumer level 50mm lenses are in-expensive, very lightweight and can be found for the most popular brands. For zoom lenses, I swear by my 24-70mm. This is a medium zoom range, which goes from quite wide-angle to a reasonable telephoto, covering the vast majority of the most popular focal ranges you will encounter. Ideally, try out both primes and zooms to discover their different ways of working.