Why would I buy an interchangeable lens camera?

Now that the cameras in smartphones have become so good, the question ‘why should I buy an interchangeable lens camera (ILC)’ ends up being very similar to the question ‘why would I buy a dedicated camera at all?’ We believe there are plenty of good reasons to buy an ILC, whether it’s a DSLR or a mirrorless camera.

The most significant of these reasons is image quality. Interchangeable lens cameras are often capable of producing better image quality, in a wider range of situations than smartphones can, so if you want your photos to look as good as possible, a dedicated camera can help.

The other benefit is that ILCs tend to give you a lot more control over your photographs. Smartphones do a great job of making the difficult decisions for you, but a dedicated camera lets you creatively engage with the process. Dedicated controls can help you enjoy the experience of taking photographs, as well delivering great end results.

Finally, the ability to switch lenses lets you create a camera + lens combination that’s perfect for taking the types of photo you want to take. Whereas a smartphone, even one with multiple cameras, tries to do a bit of everything, an ILC with the right lens can let you explore a world of close-up, wide-angle or sports photography that a phone can’t match.

So what are the most important things to consider when buying an ILC?

Sensor

The size of a camera’s sensor is one of the biggest factors determining the image quality it is capable of. Larger sensors can gather more light, which gives cleaner images and they often have higher pixel counts, giving more detail. But cameras with larger sensors also tend to be more expensive and the lenses required to give that improved image quality are larger than those of smaller sensor cameras.

The three most common sensor formats are Four Thirds, APS-C and Full Frame. Full frame is more likely to allow you to blur the background of your images, and provide clearer images in low light conditions, but by the time you’ve bought lenses, it can get quite big and expensive. For travel and hiking or for photography requiring long lenses, the smaller formats offer distinct advantages in terms of price and portability.

Lens system

Almost all camera makers use their own unique lens mount, which isn’t compatible with lenses for other systems. The camera makers also have a degree of control over which other companies can produce lenses for their systems, which means some systems have more lenses available for them than others.

Mirrorless ILCs, which don’t have the mirrors and optical viewfinders found in DSLRs are increasingly popular, but some of these systems are relatively new. This means their lens ranges aren’t yet as extensive as those of the older DSLR systems.

In addition to choosing a camera, consider whether the lenses you’ll want in the future are available. The system with the most lenses isn’t automatically the best for you: it’s more a question of whether a system offers the types of lenses you want and whether they’re reasonably priced.

Speed

Many mirrorless models can shoot bursts of photos at over 10 frames per second: a rate that, just a few years ago, was the preserve of professional sports photographers. Speeds around this number are becoming increasingly common, even in more affordable models, but it’s still worth noting the maximum frame rate and whether there are any restrictions (such as the forced use of electronic shutter) if you plan to shoot sports or fast-moving subjects.

If shooting sports is your priority, it’s also worth researching how big the camera’s buffer is, which refers to how many images the camera can capture before it has to slow down the shooting rate. Generally, more expensive models have larger buffers, and can keep shooting fast for longer.

Autofocus

Most modern cameras (mirrorless and DSLR) have autofocus systems that can measure the distance to the subject, allowing rapid refocusing on moving subjects. These systems can focus anywhere across the image, rather than being limited to a small number of points, near the center, as is the case in DSLRs.

The latest mirrorless cameras have autofocus systems that can automatically find and focus on human eyes, and the best of these are reliable enough that you rarely have to think about focus. Subject tracking systems have also become very sophisticated and can follow a specified subject as it moves, without you needing to do very much.

Autofocus systems that have been trained to recognize specific types of subject (humans, cars, dogs, cats, birds) are becoming more common, which means you can concentrate on picking the perfect moment to take your shot, rather than worrying if the camera will be focused on the right place. There’s an appreciable gap between the best and worst performers, though, so it’s worth reading some reviews to see which cameras live up to their makers’ promises.

Direct control

Less expensive cameras in each brand’s range are often aimed at less experienced photographers and tend to offer fewer buttons and control dials for quickly changing camera settings. This is great if you don’t want to learn the technicalities of photography, but may be limiting if you want a camera you can grow into as you become more knowledgeable and more confident.

More controls often make it easier to get the camera to adapt the exact demands of the types of photograph you want to take, they can also make you feel more like you’re playing an active role in the photographs you’re taking. But, of course, you’ll need to learn what each of them does, first.

Image stabilization

A lot of interchangeable lens cameras are able to monitor how they’re being held, and then move their imaging sensors to correct for any movement resulting from shake. This is especially useful when using photographing things a long distance away or in low light, where longer exposures increase the risk of camera shake. Image stabilization is also valuable when shooting video, helping to avoid distracting shake.

Some cameras don’t include any in-body stabilization, meaning that if you want to correct for vibration, you’d have to use lenses with their own stabilization systems (or invest in an external support, like a tripod). Cameras with in-body stabilization can usually correct for more types of motion and mean you get correction regardless of which lenses you use meaning that, for most people, it’s a feature worth paying a bit extra to gain. The most effective inbuilt stabilization systems can use in-body and in-lens corrections collaboratively. Standardized ‘CIPA’ effectiveness ratings give an impression of how well one system works compared with the others, but shouldn’t be taken as definitive assessments.

Nearly all new cameras include Wi-Fi to let you send images across to your smartphone. They’re generally pretty good once you’ve paired the two devices and got used to the way each brand’s app works. The best systems use Bluetooth to keep the devices paired, which reduces the number of manual steps needed for each transfer

Viewfinder / Display

Most mirrorless cameras have an electronic viewfinder, which is useful for previewing the scene when the conditions are too bright to see the rear screen. They also encourage holding the camera up to your face, which is a good way to hold the camera steady, while you’re shooting. Higher resolution finders make it easier to see what the final image will look like, and faster refresh rates (measured in Hz or frames-per-second) make it easier to follow fast-moving action. Smaller and less expensive models often omit the viewfinder to save space and keep costs down.

It’s also worth considering how the rear screen moves (if at all). Some camera designs assume you’ll use the viewfinder and have a fixed LCD panel, but most will offer at least some degree of movement, so that you can still use the camera from different angles. Most models have screen that tilts up and down, often to a great enough degree to let you see the screen when taking a selfie. More expensive models might include two-way tilting screens (great for tall-side up portrait orientation shooting) or ‘fully articulated’ screens that hinge and rotate at the side of the camera video shooting as well as selfie shots.

Battery life

Battery life is another critical consideration, depending on how much you plan to use your camera. DSLRs, which use almost no power when you look through the viewfinder, don’t need to be recharged often, but newer mirrorless cameras are gaining larger batteries to make up for this.

There’s an industry standard for testing and reporting battery life. Just as with image stabilization, these numbers shouldn’t be taken too literally, but they give a decent idea of whether one camera will shoot for longer than another. You’ll see these figures in spec sheets described as ‘CIPA’ numbers for battery life.

Charging over USB is becoming increasingly common, as is the ability to power the camera using a USB power source. It’s worth checking, but the ability to top the battery up in your car or with an external battery pack may alleviate any need to worry about battery life.

Video capabilities

The video capabilities of interchangeable lens cameras can be spectacular, with the best cameras able to capture footage that can compete with the professional video equipment, at a fraction of the price of pro gear.

Very high resolution 4K capture is increasingly common, with some models even promising 8K video. For most applications 4K is more than sufficient, and it’s features like HLG – a means of capturing bright and high-contrast scenes in a way that looks more realistic on the latest TVs – that will be more useful.

Some ILCs try to make video a relatively simple point-and-shoot affair, with autofocus tracking and limited need for user input. Others provide the complex but powerful tools used in professional cameras, requiring more experience on the part of the user, but providing much more control over the results.

Other factors worth researching if you want to shoot video, are how long the camera can record for (4K capture causes a lot of heat build-up), and how severe the rolling shutter effect is (a wobbly, ‘jello’-like distortion of movement that occurs as the camera is capturing each frame).

Weather sealing

If you plan to take your camera out into the wilds, or may need to use it in inclement weather, some higher-end models are designed to be dust and moisture resistant. Very few manufacturers make any specific promises or back these claims up with any degree of warranty coverage, but we’ve found models described as ‘weather sealed’ can be used with a little more confidence, in more challenging situations.

Flash/flash compatibility

The final factor you may wish to consider is whether the camera you’re considering has a built-in flash or a hot shoe for attaching an external one. Flashes are often thought of as being useful when there’s not enough light, but they can also be valuable in daytime, to help balance-out deep shadows. Built-in flashes tend not to be very powerful, but the ability to mount a larger flashgun or control one remotely can be a valuable addition for some types of photography.

While modern cameras generally perform very well in low light without a flash, the use of flash allows you to control your lighting, which is something you may grow into as you get more into photography.

Getting the most out of your camera

Buying an interchangeable lens camera doesn’t commit you to having to buy lots of other lenses. Most photographers settle on a couple of lenses that are well-suited for the types of subject they like to capture. But having the option to swap lenses puts you in a position where your camera can adapt to whatever types of photo you want to take, even some you haven’t anticipated yet. It’s the perfect tool to help you learn, love and grow into photography.