I will walk you through the 15 factors to consider when buying a camera lens. So by the end of this guide, you will have a basic grasp of which features matter to you.
If you recently purchased your first interchangeable lens camera, you are probably thinking about which lenses to buy.
However, choosing a camera lens that suits your specific needs is not an easy task. There are countless products on the market, not to mention all the abbreviations and specifications you need to know. And to make things even complicated, manufacturers use various terms for exactly the same features.
I know how overwhelming the process can be for beginners, as I’ve been in your shoes before.
That’s why I wrote this buying guide to help narrow down your choices. I will walk you through the factors you need to consider and how different manufacturers call them.
Let’s get on with it!
What To Look For When Buying a Camera Lens?
No matter how powerful your new DSLR or mirrorless model is, you cannot unlock its true potential until you buy a lens for it.
Sure, some cameras already come with a kit lens. But frankly speaking, it does not offer the sharpest images on the market. I also think that it defeats the purpose of having an interchangeable lens camera if you wouldn’t even consider changing the glass attached to it.
I highly suggest investing in a new lens to achieve better image quality. To help you get started, I’ll discuss the features you need to consider when choosing the right lens below.
Aperture determines the amount of light that can enter the camera sensor. It also affects the depth of field or how much of the subject is in focus.
Aperture is measured in f-stops or f-numbers, such as f/2.8. Meanwhile, the same aperture is stated as 1:2.8 on the lens marking.
The smaller the f-number of a lens, the more light enters the sensor. Consequently, a smaller f-number also produces a shallow depth of field.
Are you still confused? Here is a chart to help you determine the differences.
Basically, a large aperture is equivalent to a small f-number of f-stop, and vice versa.
In theory, the best aperture is equivalent to f/1. But in practice, the brightest lenses can only have a maximum aperture of around f/1.2.
For many photographers, a lens with an f-stop between f/1.8 to f/3.2 is more than enough for various applications.
These large aperture values offer sharp results, even when shooting in low-light conditions. They can also isolate the subject from the background, owing to the shallow depth of field.
However, lenses with a large aperture are generally more expensive than those with small apertures. But that is not always the case.
You might also encounter zoom lenses with two aperture numbers, such as f/2.8–f/5.6. The smaller f-stop indicates the amount of light you get on the shortest focal length. Meanwhile, the larger f-number shows how much light you get at the longest focal range.
Prime or Zoom Lens
Lenses can be categorized into either primes or zooms.
Prime lenses have a fixed focal length, such as 50mm. They require you to move physically away or towards the subject if you want to change your perspective. Thus, they are not the most versatile lenses available.
On a more positive note, primes are compact and lightweight, ideal for traveling. They also usually feature a larger maximum aperture, making them better in low-light.
Meanwhile, zoom lenses feature a variable focal length (more on this feature below), such as 24-70mm. They allow you to zoom in and out of the subject in just mere seconds, giving you more flexibility when shooting.
However, as expected, zoom lenses can be quite bulky and heavy. They also don’t offer the brightest aperture due to their movable elements.
Choosing between prime and zoom lenses is a matter of preference. It’s up to you to decide what works best for your needs and which one you are more comfortable using.
The focal length of a lens determines the angle of view or how much of the scene you can capture. It also indicates the magnification of the elements in the frame or how large it appears. It is measured in millimeters.
The longer the focal range, the narrower the view angle and the greater the magnification of an image.
In contrast, a shorter focal length offers a wide field of view and lower magnification.
Focal length also specifies whether the lens is a wide-angle or telephoto.
Both types of lenses have their pros and cons.
As their name suggests, wide-angle lenses feature a short focal length—less than 35mm—to deliver a wide field of view. They enable you to fit more elements in the frame. These make them ideal for capturing architecture, landscapes, and group shots. Plus, they are generally lightweight and compact.
Despite these benefits, wide-angle lenses usually create a distorted look. They also give an impression that the object closer to the camera is larger, while a subject further away seems small. For these reasons, they are not the best for portraits and general photography.
Telephoto lenses have a long focal reach of more than 75mm. They allow you to shoot distant objects at the cost of a narrower perspective. Thus, they are suitable for action, sports, and wildlife photography. They are also a great option for portraits because of the shallower depth of field.
However, telephoto lenses are usually heavy and expensive. Most models also don’t offer a large maximum aperture. These make it tricky to shoot in low-light situations.
Standard lenses stand between wide-angle and telephoto lenses. They offer a focal length of 35mm to 75mm, with the 50mm lens being the most popular. They offer the most natural perspective without noticeable distortion. Thus, they are the ideal choice for portraiture and general photography.
Most camera manufacturers produce lenses specifically for full-frame or crop-sensor cameras. This affects the compatibility of the glass based on the camera sensor size.
For instance, a crop lens can fit cameras with the equivalent sensor. However, it is not compatible with full-frame models. If you try to use one, it will just give your images heavy vignetting.
Meanwhile, a full-frame lens is compatible with both full-frame and crop cameras. However, it leads to a crop factor (more on this topic later on) if you attach it to a smaller sensor.
To differentiate full-frame mounts from crop-sensor ones, several manufacturers use the following abbreviations.
- Canon EF – Full-frame DSLR
- Canon EF-S – APS-C DSLR
- Nikon FX – Full-frame DSLR
- Nikon DX – APS-C DSLR
- Sony FE – Full-frame mirrorless
- Sony E – APS-C mirrorless
- Fujifilm X – APS-C mirrorless
When you attach a lens—whether it has a crop or full-frame mount—to a crop-sensor (APS-C) camera, it can affect the field of view.
Although it offers the exact focal length, the same lens on a crop camera gives you a tighter perspective. That is because it covers a smaller portion of the sensor, leading to a cropped look.
For this reason, a wide-angle lens like 35mm is not as wide anymore. Meanwhile, a telephoto lens makes objects appear closer.
All this jargon might be too overwhelming for a beginner.
Fortunately, manufacturers developed an easy way to measure the “equivalent” focal length of a lens when attached to a crop-sensor camera.
Simply take the provided crop factor number and multiply it with the focal length of the lens. The product is the equivalent focal length relative to a full-frame 35mm camera.
For instance, a Nikon 50mm lens offers an effective focal length of 75mm when mounted on a camera with a 1.5x crop factor. This focal range is ideal for portrait photography.
Below are the crop factors from top camera manufacturers.
- Canon – 1.6
- Nikon – 1.5
- Sony – 1.5
- Pentax – 1.5
Some manufacturers include image stabilization in their camera bodies. These include Sony, Olympus, and Pentax.
However, others, notably Canon and Nikon, still prefer to stick with built-in lens stabilization.
This stabilized lens corrects camera shake by at least several stops, giving you sharper images. It also enables you to shoot handheld or at slower shutter speeds without worrying about image quality. These are done by moving elements in the lens.
Manufacturers use different abbreviations to specify that their lenses have built-in image stabilization.
- Canon – IS (Image Stabilization)
- Nikon – VR (Vibration Reduction)
- Sigma – OS (Optical Stabilization)
- Tamron – VC (Vibration Control)
- Sony – Image stabilization in the cameras
- Olympus – Image stabilization in the cameras
- Pentax – Image stabilization in the cameras
In the past, cameras used screw-drive lenses, which don’t have an internal motor. So if you want to adjust focus, it requires you to turn the focus ring manually.
Today, autofocus is a common feature among lenses. Most products also allow you to switch between auto and manual focus easily.
This feature is handy for achieving sharp, in-focus photos. It can also be useful for tracking an object even when it is moving across the frame.
However, no autofocus system is the same. Each one varies in terms of speed and noise.
Below are the three most common autofocus drive types on the market.
- Micromotor drives – They feature a small, simple motor inside the lens to control some gears. These will then move the lens elements to adjust focus. AF performance can vary greatly, from slow and noisy to fast and quiet.
- Linear stepper motors – They are common among lenses for mirrorless cameras. They offer fast and near-silent autofocus during video recording.
- Ultrasonic-type motors – They are popular in DSLR lenses due to their fast and silent autofocus performance. They also allow full-time manual override of autofocus for total control over the lens.
As always, manufacturers refer to their autofocus motors in various initials.
- Canon – Ultrasonic Motor (USM)
- Nikon – Silent Wave Motor (AF-S)
- Sony – Supersonic Wave Motor (SSM)
- Pentax – Supersonic Drive Motor (SDM)
- Olympus – Supersonic Wave Drive (SWD)
- Sigma – Hypersonic Motor (HSM)
- Tamron – Ultrasonic Silent Drive (USD) or Piezo Drive (PZD)
- Tokina – Silent Drive Module (SD-M)
Weight is usually an overlooked factor when choosing a camera lens. However, it is important to consider how much a lens weighs before buying one, especially if you already own a heavy camera.
Some lenses, especially zoom and telephoto ones, are considerably large and heavy. That is because they contain more elements inside their bodies, which add to the overall bulk.
So if you want something light and compact, consider investing in prime lenses instead. You can easily fit and pack these lenses inside your bag, suitable for traveling and street photography.
Build Quality and Weather Sealing
In general, expensive lenses have better build qualities and are more durable. They use robust materials that make them heavier than your average lenses.
Some lenses also include weather sealing, which protects them from dust and water. This feature is usually reserved for high-end lenses, though.
On the other hand, cheap lenses tend to be lightweight because of their plastic construction. Several prime lenses also use plastic to keep their weight and price low. However, they are also available in more expensive versions.
In my opinion, a weather-sealed lens is nice to have if you often shoot outdoors or in inclement weather. However, if you usually shoot indoors or in a studio, it is not as important.
I highly suggest determining your shooting needs first before deciding if you need weather sealing.
Camera makers produce different lens mounts specifically for their product line-up. Thus, you can’t swap lenses across brands. For instance, a Nikon lens wouldn’t fit on a Canon body.
There are some exceptions to this—both Panasonic and Olympus use the four-thirds and micro four-thirds mounts for their mirrorless cameras.
Several third-party manufacturers, such as Sigma, Tamron, and Tokina, also make lenses in various mounts to fit different camera brands.
Below are the various lens mounts available on the market today.
- Canon – EF, EF-S, EF-M
- Nikon – F, Z
- Sony – A, E
- Pentax – KAF, Q
- Fujifilm – F, XF
- Olympus or Panasonic – Four Thirds, Micro Four Thirds
- Samsung – KAF, NX
You can also use an adapter to fit a Nikon lens to a Canon body. However, it usually comes at the cost of slower AF performance or vignetting. I still recommend using the specific lens mount for that brand.
Your budget is one of the most important factors when choosing a camera lens.
In general, the more you spend on a lens, the better the image quality and build it has. However, this isn’t always the case.
You can find countless lenses that offer impressive performance at low prices. So if you are on a budget, consider getting these cheap lenses.
But if you have the money, I highly suggest investing in higher-end lenses instead. These provide excellent image quality that you won’t get from inexpensive glass.
You may also want to consider the following features if you are into a specific type of photography.
Macro lenses come in various focal lengths, but they share the same feature—1:1 magnification ratio. They allow you to get close to the subject and render it in the same size on the sensor. Thus, they make small objects appear life-size or even larger.
Macro capability in a lens is ideal for close-up, nature, insect, and food photography.
Color Refractive Correction
When light enters the sensor through the lens, it usually bends in various directions. This can result in color shifts or aberration, especially near the edges of an image, which affects overall photo quality.
To counteract this, manufacturers use a low-dispersion glass when producing their lenses. Fortunately, most lenses today have this feature.
But if you want to make sure if a particular lens has it, look for the following labels.
- Canon – UD
- Nikon – ED
- Sony – ED
- Pentax – ED
- Sigma – APO
- Tamron – LD
Distortion is another common problem when light enters the sensor. It occurs when straight lines on the edges of the images are bent inward or outward. A professional photographer who dabbles in landscape photography usually finds this issue bothersome in their work.
Fortunately, most lens manufacturers correct this during construction. Still, it is best to double-check the lens specifications if it has this feature.
- Pentax – AL
- Sigma – ASP
- Tamron – AD
Perspective or Focus Shift
If you want to adjust perspective when shooting, consider getting a tilt-shift lens.
This specialized lens allows you to change the focal plane of a lens. And depending on the positioning of optics, it can distort perspective. Thus, it makes objects appear smaller or bigger than their actual size.
A tilt-shift lens usually offers a wide field of view ranging from 17mm to 35mm. It is ideal for architecture, fine art, and landscape photography.
Below are the abbreviations that identify a tilt-shift lens among countless options on the market.
- Canon – TS
- Nikon – PC
Choosing the right lens is a tricky business. It’s easy to get lost in the hundreds of options on the market and all the jargon.
Hopefully, this article about how to choose a camera lens can help narrow down your lens choices.
However, always remember that no one lens can rule them all. It’s best to determine your needs and preferences first, so you can make the right purchasing decision.