DSLR vs mirrorless cameras: which is better?

With the EOS R System including both APS-C and full-frame options there’s now a wide choice of mirrorless cameras offering new advantages to professionals and amateurs alike. But whether you want to upgrade from an older camera or step up from a compact camera to one with interchangeable lenses, which is better, a mirrorless camera or a traditional DSLR?

Here, to help you make a choice, we look at the differences between DSLRs and mirrorless cameras, with expert insight from Canon Europe Senior Product Specialist Mike Burnhill.

• DSLR vs mirrorless: body size and weight
• Lens mounts: is mirrorless better than DSLR?
• Lenses and compatibility: can you use DSLR lenses on a mirrorless camera?
• Optical vs electronic viewfinders: which is better?
• Image quality: do mirrorless cameras take better photos?
• Autofocus: mirrorless vs DSLR
• Mechanical shutter vs electronic shutter
• Battery life: DSLR vs mirrorless
• Mirrorless or DSLR: making a choice

"One of the key things about DSLRs is that they have a mirror or pentaprism to direct light through to the viewfinder," Mike explains, "but this has to have room to flip out of the way to expose the sensor. Eliminating this helps reduce the size and weight of the camera, particularly when you compare the EOS R7 and EOS R10 to similar DSLR models such as the Canon EOS 7D Mark II or the EOS 90D."

Lifestyle content creator Diana Millos used the EOS R10 to photograph the culture and architecture of Andalusia. She comments: "The EOS R10 almost looks like a toy when you come from a camera that's much heavier, such as the EOS 80D that I use. I like that it's small and lightweight, yet it's still just as powerful."

The EF mount used in Canon's DSLR cameras was introduced in 1987, so it's a very well-established system. There are hundreds of compatible lenses available, with an EF lens to cover just about every focal length, and a range of more compact and often more affordable EF-S lenses for EOS DSLRs with APS-C sensors.

However, the RF mount used on EOS R System cameras introduced many innovations. "The RF mount has been designed with an eye to the future," Mike explains, "such as improving communication speed between camera and lens and adding extra contacts to support more functions." These include much faster autofocus performance, real-time Digital Lens Optimisation, and enhanced controls such as the customisable control ring on RF lenses.

Instead of having to constantly work around a DSLR's reflex mirror between the mount and the sensor, lens designers can bring RF lenses closer to the sensor itself, enhancing optical performance. This has resulted in faster, brighter lenses with exceptional quality, as well as groundbreaking lenses such as the RF 5.2mm F2.8L DUAL FISHEYE lens, which captures 180° VR images on compatible full-frame cameras.

If you already have EF or EF-S lenses, it's easy to use them with mirrorless EOS R System cameras, with no loss of quality or functionality, thanks to a choice of EF-EOS R mount adapters. This also gives you scope to mix and match specific lenses from both formats (particularly if you have a favourite or specialist lens not yet available in an RF mount version) and get the best of both worlds. There's even a mount adapter with a lens control ring and one with drop-in ND or polarising filters, adding more versatility to your EF lenses than you get with the same lenses on a DSLR.

It's important to note, however, that it's not possible to use RF lenses with a DSLR camera. So if a particular RF lens appeals to you, then you'll need to choose an EOS R System mirrorless camera.

DSLRs have optical viewfinders, which some photographers prefer using because they give you a direct connection with the scene. In the past, the electronic viewfinders (EVFs) used on mirrorless cameras have suffered from shortcomings such as lag, but they are getting better and better – the latest EOS R System cameras have EVFs with high refresh rates of up to 120fps, meaning virtually no perceptible lag – and they have their advantages too.

In particular, if you're using an EOS R System camera, Exposure Simulation makes it possible to preview the image with your exposure, Picture Style and other settings applied, both in the viewfinder and on the rear LCD screen. On a DSLR, Exposure Simulation works when you use the rear screen in Live View mode, but not in the viewfinder. With an EVF, you can also compose your shot and focus in low-light conditions too dark to see with the naked eye through an optical viewfinder. When you're shooting video, the EVF in EOS R System cameras offers the same manual focus assist display as Canon's professional Cinema EOS cameras.

Wildlife photographer Dani Connor, who used the EOS R7 on a trip in search of the endangered Iberian lynx, found that working with an electronic viewfinder completely transformed her photography.

"With a DSLR viewfinder, it's often easier to take a test shot and check the image on the rear screen before deciding what settings to change," she says. "But with a mirrorless camera, it's so useful to see the effect that a change in settings has without having to take my eye from the viewfinder.

"If I need to react quickly when photographing wildlife, or maybe the light is constantly changing, I can quickly adjust my ISO or my shutter speed and I can see what my photo will look like."

"Capturing images using the two systems isn't radically different when it comes to the actual final image quality, but it's everything that goes around it that really makes the difference," says Mike.

"For example, with the RF mount, one of the benefits of high-speed communication between the lens and the camera is that when you have optical problems like diffraction and aberration, we can do in-camera correction of those in real-time. This instant processing means that in some ways you're actually getting better image quality out of the new cameras."

Similarly, in some situations, mirrorless cameras, such as the EOS R7 with its continuous shooting speed of up to 15fps using the mechanical shutter and 30fps using the electronic shutter with full autofocus tracking, are more likely to produce consistently usable images than the EOS 7D Mark II or the EOS 90D, both of which have a maximum continuous shooting speed of 10fps.

EOS R System mirrorless cameras including the EOS R5, EOS R6, EOS R7 and EOS R10 use Canon's latest Dual Pixel CMOS AF II autofocus system, in which every pixel in the sensor is used for both focusing and imaging, compared with the specific point-based phase detection sensor focusing through the viewfinder for cameras such as the EOS 7D Mark II and the EOS 90D.

One of the big advantages of these mirrorless cameras is the ability to select an AF point anywhere within the frame. "This is impossible on a DSLR," Mike explains, "and it also allows for capabilities such as face tracking, eye tracking and animal tracking that we see in these cameras. You can, for example, pick up the eye of a bird in flight, and follow that around the frame – again something that is impossible for a DSLR.

"That said, some pro DSLRs have a separate focusing chip, so although the overall autofocus system might be limited compared to newer mirrorless cameras, it can also be faster in certain situations thanks to that dedicated AF chip."

A few DSLRs – notably the EOS 90D and EOS-1D X Mark III – have electronic shutters in addition to mechanical shutters, but usually DSLRs have mechanical shutters. All of Canon's EOS R System mirrorless cameras, on the other hand, have both types of shutter.

With an electronic shutter, the mechanical shutter is locked open and the imaging sensor is essentially read electronically. The biggest advantage of this is that shooting can be totally silent – not just quieter, with the shutter damped or suppressed as it is when you select the S ("soft" shooting) option available on some cameras, but completely noiseless. This can be invaluable when you're photographing nervous wildlife, slumbering babies or the quiet parts of weddings, for example.*

Electronic shutters also enable faster continuous shooting. "With mechanical shutters," Mike says, "the fastest possible in our DSLR cameras was 16fps [frames per second] on the EOS-1D X Mark III, a high-level professional camera. With its electronic shutter, the EOS R10 can give you the option of up to 23fps for a fraction of the price, while the EOS R7 can shoot at 30fps, matching the speed of the EOS R3, another professional camera, but for a third of the price."

However, the phenomenon of "rolling shutter" can be a problem when you photograph action with an electronic shutter – fast-moving objects such as a swinging golf club or a rotating propeller can move in the time it takes for the whole frame to be read, leaving them distorted in the resulting image. The phenomenon is greatly reduced in the latest mirrorless cameras, but mechanical shutter is recommended for shooting fast-moving action.

Shooting with electronic shutter in some artificial lighting, notably fluorescent lights, can be problematic if the light is out of phase with the shutter. For similar reasons, using flash with electronic shutter can result in uneven exposure across the frame.

It's often said that DSLRs have longer battery life than mirrorless cameras, mainly because a mirrorless camera's electronic viewfinder requires power while a DSLR's optical viewfinder uses none. In practice, however, battery life depends a lot on how you use the camera – using flash, for example, will consume more power on both types of camera, while using the LCD screen on a DSLR typically consumes more power than using the LCD screen on a mirrorless camera. A mid-range DSLR such as the EOS 90D offers 1,200 shots or more with the viewfinder and 450 with the LCD, while the mirrorless EOS R6 delivers 380 shots with viewfinder or 660 with LCD in its highest performance/most responsive mode. In the power saving mode it's 500/770 using the EVF/LCD respectively.

The difference is even greater at the pro level: if you stick to the viewfinder on the EOS-1D X Mark III, for example, you could shoot 2,500 images before the battery runs out, but this falls to 600 images if you rely on Live View, as compared with the mirrorless EOS R3's 620 shots with viewfinder and 860 with LCD. So if you prefer to use the rear LCD screen, mirrorless cameras may well give you more shots on a single charge.

Both mirrorless cameras and DSLRs have their strengths and weaknesses. Which is better for you depends largely on the type of photography you do and the advantages you want to have when using your camera/lens of choice.

If you want a lightweight camera with fast frame rate for travel photography, then a mirrorless camera such as the EOS R10 may be ideal. If you want to use next-generation RF lenses, then the mirrorless EOS R System is for you, with accompanying benefits including in-camera image correction and AF tracking performance, plus the capability to use your favourite EF lenses thanks to the range of EF-EOS R Adapters.

If you want to preview your image in the viewfinder with shooting settings applied, then a mirrorless camera's electronic viewfinder will suit you – but Live View on the rear LCD screen of a DSLR will do the same, while a DSLR's optical viewfinder eliminates even the extremely slight lag of the fastest EVFs in mirrorless cameras, as well as delivering longer battery life.

Advanced autofocus features such as Animal Eye AF and Vehicle AF are available only in the latest EOS R System cameras, but the dedicated AF chip in pro DSLRs can be faster. EOS R System cameras give you the freedom to shoot with either an electronic or mechanical shutter, while most DSLRs feature a mechanical shutter only. If completely silent shooting is vital for you, and you're not photographing fast-moving action where rolling shutter could become an issue, then you will benefit from the option of an electronic shutter.

From ergonomics to autofocus, shutter type to shutter speed, try out the camera you're interested in, if you can – there's no substitute for actually feeling how it suits you.



*Sounds other than the shutter (aperture, focus lens drive sound, electronic sound, etc.) may be generated.


Written by Amy Davies and Alex Summersby