Mirrorless vs DSLR cameras: what’s the difference? We look at the benefits and downsides of the two leading camera technologies.
In case you’re too busy to read this entire article, let’s boil down the appeals of mirrorless and DSLR cameras for a quick shot of insight.
Both DSLRs and ‘mirrorless’ cameras are models with interchangeable lenses – the main difference is that the latter generally use an electronic viewfinder rather than an optical one, which requires an internal mirror to reflect the light to your eye. This has lots of knock-on effects for how the camera takes photos, which we’ll explore later.
Mirrorless cameras are smaller, the right style to pick if you want a camera to take around all the time. Many models can take just as good photos as a DSLR too, and tend to be better for video capture.
DSLRs from Nikon and Canon let you choose from a wider selection of lenses and, because they’re larger, their batteries last longer. If you want to learn to shoot in quite a traditional way, manually controlling elements like shutter speed, then the chunky grips many DSLRs have are a big ergonomic benefit.
A DSLR also gives off a good impression if you want to dip your toes into paid photography work. That said, a mirrorless model can also make a terrific professional tool.
So, that’s a nutshell summary of the two systems. Ready to delve into some of their intricacies and specific advantages? Let’s take a look…
Related: Best DSLRs 2018
Mirrorless vs DSLR – How DSLR cameras work
What’s the big difference between a DSLR and a mirrorless camera? DSLRs use a mirror that reflects the camera’s view of a scene up to a viewfinder.
You get a view of the scene that is not passed through the camera’s electronics.
When you press the shutter button, the mirror flips out of the way. The light that was reflected into the viewfinder now hits the sensor instead of the mirror. And the sensor gathers the light that makes up the final image.
This mirror and viewfinder array is why DSLRs have a characteristic shape, with a ‘mound’ on top where the viewfinder lives.
If you don’t mind a larger camera, DSLRs are a great choice. However, all DSLRs are relatively large, in part because of this mechanical aspect that can’t be shrunken down as easily as other kinds of tech.
There are reasons to embrace the style of a DSLR if the bulk won’t put you off taking it out to use, though. Controls are generally well-spaced, there’s room for ergonomic grips and a large battery.
DSLRs also tend to have very intuitive manual controls. Shoot in a manual style and you get a sense of direct connection with your photography that is particularly satisfying.
Mirrorless vs DSLR – How mirrorless cameras work
Mirrorless cameras (also known as CSCs or DILCs) are the more techy, less traditional, alternative to a DSLR. They cut out the moving mirror part, letting them slim down significantly.
Instead you get an electronic viewfinder (EVF), an image preview based on what the camera sensor can ‘see’. EVFs have improved hugely over the last five years, but in low light conditions a DSLR’s optical viewfinder will look clearer. And even the most expensive cameras still have EVFs that may seem a little pixellated to the pickiest among you.
The new Nikon Z6 has a 1280 x 960 resolution viewfinder, while its Sony Alpha A7 III rival (below) has an 1024 x 768 equivalent: great in their class, but significantly lower resolution than Full HD. You’ll usually see viewfinder resolution written as so many thousand ‘dots’, which makes them seem higher-res (or sharper) than they are.
The good news is there doesn’t need to be any picture quality trade-off with a mirrorless camera. Sensor size is the biggest determinant of image quality, and you can get APS-C and full frame mirrorless models just like DSLRs. APS-C denotes a smaller sensor than ‘full frame’, but only the top models from Sony and Nikon use the larger style.
Fuji even makes a medium format mirrorless camera, the FujiFilm GFX 50S, with almost twice the area of a full frame camera. It costs £5999, mind.
You’ll find APS-C mirrorless cameras from Sony, FujiFilm and Canon. Panasonic and Olympus models have smaller Micro Four Thirds lens mounts and sensors, which perform less well in poor light. However, Panasonic’s cameras are hard to beat for the video modes they offer at the price.
There’s a lot of love left for DSLRs, and they are still used by most pro and semi-pro photographers. However, mirrorless cameras have developed and improved more quickly than DSLRs over the past half-decade. Anyone who claims a mirrorless camera cannot be used as a professional tool is, well, plain wrong.
Let’s take a closer look at their special skills so you can decide which is best for you.
Related: Best mirrorless cameras
1. Better lens ranges
Because of their longer history, DSLRs have access to more lenses than mirrorless cameras. Canon and Nikon DSLRs, in particular, are compatible with a huge range of lenses. There are ones made by the camera makers’ own lens divisions, and alternatives made by Tamron, Sigma, Samyang and Zeiss.
Popular mirrorless series like Sony’s Alpha range also have a lot of third-party lenses, but they can’t quite compete with the classic Nikon and Canon styles yet. The best idea is to see which lens standard the camera you are considering uses, then dig into what’s available.
For most of us, the dream lens is one that is sharp, has a fairly wide maximum aperture and does not cost too much. A high-end lens can easily cost much more than the lens itself, so make sure your needs are covered before investing.
There’s another benefit to DSLRs here. Larger lenses tend to feel better-balanced on a larger DSLR body than a small mirrorless one.
2. A traditional viewfinder
DSLRs use an optical viewfinder, where the image you see through a camera’s tiny porthole is an exact view of the world, simply reflected off a mirror. A mirrorless camera’s electronic viewfinder (or EVF, which is used in most but not all models) displays what the camera sensor sees on a tiny screen. Like the monocle version of a VR headset.
An optical viewfinder will look much clearer for low-light shooting, and has none of the blockiness of a lower-end EVF. Not all optical viewfinders are made the same, though.
Look at the viewfinder ‘magnification’ and ‘frame coverage’ when researching a DSLR camera. These tell you how large the image will appear through the viewfinder, and how close the scene displayed will be to the final image. You ideally want at least 95% coverage.
3. Much better battery life (usually)
DSLR battery life is usually much better than that of a mirrorless camera. The first reason is obvious: DSLRs are larger and therefore can fit in bigger batteries. Mirrorless cameras at the same level often have more techy features, including an electronic viewfinder, which can be a further power drain.
How big a difference are we talking about? Nikon rates its new entry-level D3500 at 1,550 shots per charge. The smaller but more portable Panasonic GX800 is rated at just 210 shots. It’s a huge disparity. The larger Panasonic Lumix GX9 will last for up to 900 shots, but you’re still more likely to need a spare battery when out shooting for the day with a mirrorless camera.
Professional DSLRs like Nikon’s D850 (below) also often have battery grip accessories available to further boost shooting time, although these are now available for some mirrorless bodies like Fujifilm’s X-H1.
4. A more professional look and feel
If you have aspirations of being taken seriously as a wedding or event photographer, you may want to consider a traditional DSLR rather than a mirrorless camera. This is an unfortunate point for something like the Sony Alpha A7 III, which is a genuine pro-grade camera. However, to some only a big DSLR looks like one.
There are knock-on benefits to a DSLR’s design, though. They tend to have much deeper grips than mirrorless cameras, giving you a steadier hold. This is more comfortable if you’ll need to shoot for hours at a time, and makes shooting with big, heavy lenses easier.
5. Better autofocus performance, in some cases
In the early days of mirrorless cameras, they were almost universally slower to focus than DSLRs. This is because they used, for the most part, contrast detection autofocus.
DSLRs use phase detection when shooting stills, and it is traditionally faster. However, today’s mirrorless cameras have hybrid systems that compare fairly well with DSLR focusing.
It depends on the model you can afford, though. The FujiFilm X-A5, for example, is not an autofocus master and you’ll get better results from the Nikon D3500 DSLR. You have to consider AF speed carefully when shopping for a mirrorless camera as it will radically alter how many shots you miss when shooting moving subjects.
Sony deserves some plaudits here, though. Its relatively affordable Sony Alpha A6000 mirrorless camera has a great AF system.
Related: Best Canon lenses
1. They are smaller and more portable
The best argument for a mirrorless camera is they are almost always smaller and lighter than DSLRs. When you are researching what camera to buy next, it’s too easy to discount how these factors will affect how much you will use one.
A camera that takes mind-blowing photos is not much use if the inconvenience of its bulk means you take it out every six months instead of every week.
For the ultimate portable package, consider a mirrorless camera with a slim zoom or ‘pancake’ lens. This is a non-zoom lens, usually with a fairly wide field of view, but it’s deliciously convenient for street photography. The Panasonic GX800 is one of the best ultra-portable options. It’s only 33mm thick and has a very small footprint.
By contrast, the Canon EOS 4000D entry-level DSLR is 77mm thick. We know which one we’d rather carry around during a casual walk around the local park.
2. An EVF can be very useful
Most mirrorless cameras have something called an EVF as well as a rear display. This is an electronic viewfinder, the digital equivalent of what you get in a DSLR.
We’re not photography snobs. There’s nothing wrong with composing your shots using the rear screen, but on a very bright day you’ll get a clearer view with the viewfinder.
The downside of an EVF is that until you start looking at very expensive models, their display resolution is quite low. For example, Sony’s great A6000 has a 800 x 600 pixel viewfinder. That’s probably a lot lower-res than your phone’s screen.
However, an EVF can show you what your final image will look like, more-or-less, whereas a DSLR just shows a clear view of the scene bounced off a mirror. It may be clear, but the final image may well look quite different, with variances in exposure and dynamic range. EVFs are also fantastic for something called focus peaking.
This is a feature used for manual focusing. It highlights the sharpest parts of an image, usually outlining them with red or white. Manual focusing goes from being a skill to a doddle.
3. They are often better for video
DSLR cameras are slower to adopt new features than mirrorless ones, because they trade on traditional camera values rather than those of hot new tech. You have to spend an awful lot on a DSLR to get one capable of shooting 4K video, for example.
However, stick to mirrorless and you get 4K video at the same price as an entry-level DSLR. Panasonic offers the best low-cost options for video shooters. Its Lumix GX800 shoots at 4K, and for £299 you get a lens with optical stabilisation, which makes handheld footage look less wobbly.
Mirrorless cameras, like this one, are also more likely to have preview screens that flip around so you can check the footage as it’s captured. That’s particularly useful for vloggers and YouTubers.
Keen on video? There are other points to note too. Look for a camera that lets you plug in an external mic, for better sound recording, and one with in-body stabilisation for smoother footage. If you have quite a lot of money to spend you may want to consider a Sony model like the A6500. Sony’s mirrorless cameras have larger sensors than Panasonic’s, making them better for low-light shooting.
4. You can get away with using them in more places
A professional look isn’t always desirable. Using a DSLR will attract the attention of security guards and officials at events. This is an issue at places that require either a shooting permit or just have a far too proactive security team.
You’re much more likely to be asked to stop shooting, or whether you’re a professional or simply a tourist, if you use a big professional-looking DSLR. A small mirrorless camera with a normal-looking lens is much more likely to be pegged as a tourist or amateur piece of equipment. You’re more likely to be able to shoot away with impunity with one.
5. Simpler operation
Most DSLRs and mirrorless cameras can be used like point-and-shoot cameras. They will have auto modes that take all the tricky parts away from your fingers, like manual focus and shooting parameter control.
However, if you’re accustomed to the feel of a phone, you may prefer the style of mirrorless models. They are more likely to have a touchscreen, and a screen that flips out for easy selfies. The FujiFilm X-A5 and Panasonic GX800 are obvious choices if you want a breezy, entry-level shooter.
Conversely, DSLRs focus more on chunky control wheels and big nav buttons. These are very useful if you want to control elements like the exposure and shutter speed yourself, but many of you will simply want the camera to handle this itself most of the time.
If you think a smaller, portable frame will make your take a camera out more often, you should buy a mirrorless camera rather than a DSLR. Consider an advanced compact from the Sony RX100 series too if portability is really paramount.
Care as much about video as stills? Again, mirrorless is often the right choice.
There are two great reasons to pick a DSLR instead. They are great if you want access to the widest choice of lenses. Or if you’ll need to shoot for long periods at a time and appreciate the ergonomics of a DSLR. They are usually shaped to your hands better than a mirrorless alternative.
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Luckily, we’ve rounded up all of our favourite DSLR cameras and mirrorless cameras. If you’re still undecided and want to see them all in one place, there’s also our best cameras guide. Happy shooting.