What are the differences between a prime lens and a zoom lens?
Zoom lenses allow you to change how close you want to get to a subject while keeping your physical distance. But this feature comes at a price though: quality and aperture.
So, which is best… prime vs zoom? This post should clear up any misconceptions you have about either and help you to find the right option for you.
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So what is a prime lens exactly? Do prime lenses zoom? As I stated above, prime lenses have a constant focal length. In other words, they don’t zoom. And like any other piece of equipment, it has its advantages and disadvantages.
One issue with using primes is that you may not be able to get the photo framed as you’d like it. But at the same time, they make you experiment more. They force you to think of a different way around taking a photo, one you may have missed otherwise.
There are two distinct reasons why people buy prime lenses, though: quality and aperture.
The quality of the prime lens is often vastly superior to that of a zoom as it doesn’t have as many moving parts.
Furthermore, primes also have fewer optical elements inside. That means there are lesser chances of abnormalities to occur. And as a result, it is better at producing sharper images.
There used to be a considerable difference between prime and zoom lenses because the technology wasn’t as good.
But now you can get zoom lenses that are just as good as some primes. But they come at a price.
I paid £1000 for my 24-70mm f/2.8 and £1040 for my 35mm f/1.4. The quality of this zoom lens is excellent but still isn’t quite as good as the f/1.4 prime.
Even when you’re investing a lot of money into a zoom lens, you’re still making a compromise.
You can see how sharp the image is below – it’s hard to believe that I shot this at f/1.4, the widest aperture I have.
In contrast, zoom lenses would have a bit more trouble producing an image as sharp as the one above.
Primes have a lot less moving parts, so they’re not constricted by the zooming action. Therefore, they often have wider apertures than zoom lenses.
The main advantage of having a wide aperture is that you can take photos in low light. The wider aperture allows more light into the camera.
The wide opening makes it ideal for shooting indoors: in a bar, a club, or in a dimly lit room – somewhere where you don’t want to push your ISO.
The prime option that I mentioned above allows four times as much light into the lens than the zoom. An aperture of f/1.4 is four times larger than f/2.8. Keep in mind that f/2.8 is very good for a zoom lens.
We also have the advantage of producing a shallow depth of field which has a whole range of creative uses. Portrait photographers usually much prefer primes because of this. A soft, creamy background is often precisely what people like to see in portraits.
I shot this photo below at f/1.4, producing beautiful bokeh. Since zoom lenses can only go up to f/2.8 at most, they are not capable of producing background blur as well as primes.
Another significant advantage of most prime lenses is that you can buy them for a low price. For instance, you can get a 50mm f/1.8 ranges from around $110-$220. For that price, you’ll see a dramatic increase in quality over your kit lens. You’ll also gain the ability to play around with depth of field a lot more.
But it’s also worth noting that primes can get more expensive as the focal lengths increase. While you can get a 50mm for a few hundred dollars, you may have to shell out thousands for a 500mm.
Some specific lens constructions would be impossible to adapt to a zoom lens. One of them is tilt-shift lenses.
A tilt-shift allows you to manipulate your perspective by shifting parts of the lens. You can also modify your focal plane’s direction by tilting some of the elements. The effect it creates results in a unique, “mini-world” look.
These lenses are the workhorses of professional interior and architecture photographers. But they are also used in portraiture and event photography sometimes.
Another type of specialised primes is the defocus-controllable lens. This useful tool allows the photographer to alter the form and amount of background blur without actually changing the aperture. It’s the hidden gem of portrait photographers.
Super telephotos are also rare to find in zoom format. There are some excellent 150-600mm options out there, but that’s where it stops. Focal lengths of 800mm and above (with astronomical prices) are exclusively primes.
Zoom lenses are perfect for beginners because of their variable focal lengths. In other words, they let you zoom in and out of a scene as opposed to primes.
Zoom lenses are a lot more complicated, and the prices vary a lot more, depending on what the lens does.
It’s a common misconception for beginners to think that an 18-250mm should cost more than a 24-70mm zoom lens because it has a longer focal length. That’s not true because it does so at a price.
When it comes to zoom lenses, you do get what you pay for. It would be hard to compare the two options that I just mentioned because they have different purposes.
So what are zoom lenses good for?
An 18-250mm is for the hobbyist. Often someone who doesn’t want to carry around multiple lenses – perhaps someone who travels a lot.
A 24-70mm is for a much more serious shooter. Often someone who understands the compromises made when building a lens with a much longer zoom range. But, at the same time, they need to be able to change the way they’re framing a photo freely. You can’t do this with a prime.
The overall image quality of zoom lenses is catching up with that of prime lens options, but I reckon there’s still a long way to go.
I notice that my zoom isn’t as sharp as my prime. But I knew that when I bought it and I’m still delighted with the results. You could call it a happy compromise.
One thing I have noticed from using both types of lenses is that the photos appear a lot softer when the aperture is all the way open, and the pictures look better at a stop or two narrower.
This noticeable with zoom lenses, but that’s just part of the compromise.
There is one thing to keep in mind, though. An expensive zoom can easily surpass a cheap prime in image quality, even though there are exceptions to this (like the Canon 50mm).
Zooms are less sharp because of optical errors coming from their complex nature. Expensive unique glass elements and coatings correct some of these errors. As a result, you’ll see a drastic increase in quality.
So, there is quite a considerable quality overlap between the two. There are websites out there that will show you sharpness samples and MTF charts. They can give you a general idea of how a particular lens performs.
But if you’re planning on getting a new lens, I advise getting your hands on it and have a quick test. There’s a lot more to it than sharpness and aperture.
Because the aperture is f/2.8 throughout the 24-70mm zoom range, I always know what the parameters are. However, cheaper lenses often lack this feature.
A more inexpensive zoom, such as a Canon 18-55mm kit lens, will have an aperture of f/3.5 when it’s zoomed all the way out at 18mm. But it slowly narrows the aperture to f/5.6 as you zoom in, letting in less than half the amount of light.
To reach f/2.8 throughout the entire range is an achievement not very common with crop sensor lenses. But all three large brands now offer f/2.8 standard zooms as part of their advanced crop sensor systems. They are quite expensive, though, even nearing their full-frame counterparts.
Some zooms go beyond the notorious f/2.8 frontier. A few years ago, photographers praised Sigma for introducing an 18-35mm f/1.8 and a 50-100mm f/1.8 for crop sensor cameras. These have since become very popular in the mirrorless videographer community, but also among photographers. They are relatively affordable, especially for what they offer.
Not long ago, Canon introduced a 28-70mm f/2 to go with the new RF system. It’s a beast of a lens for sure, at a beast of a price. But some professionals love it for its image quality and large aperture.
Quality zoom lenses can cost a lot of money, but they do reach a limit. A good zoom can only do so much before the lens maker has to stop making compromises and start making a new version for a different focal range.
When you start buying lenses, it’s often a cheaper and more sensible option to purchase a zoom. You can do more with it.
So are prime lenses better than zoom?
There will always be prime lenses and zoom lenses in my camera bag because they have very different uses.
I will use a prime when I know what I’m shooting and the focal length that fits the situation. Or I’ll use it if I’m shooting in low light and want to allow more light into the lens. But I probably still use a zoom more often. It’s not a better option, but I can do more with it and, even though it’s heavier, it’s worth the extra weight.
I would encourage everyone to use a prime. Not only did I find that my photos started coming out a lot better after using one, but it taught me a lot about aperture and depth of field.
Which do you think wins the zoom vs prime argument?
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