Mirrorless or DSLR Cameras: Which is Right for You?

20th June 2018

When it comes to capturing high quality images, people tend to gravitate towards either a DSLR camera or a mirrorless camera. Canon’s DSLR range is known as EOS DSLR cameras, and in mirrorless cameras Canon have 2 range options, EOS R and EOS M—we will get in to more about that later.

Both DSLR and mirrorless cameras use interchangeable lenses, which can be swapped as needed. Both systems are capable of capturing very high quality images and generally speaking, both systems also offer a degree of manual—as well as automated—control.

So how do you know which system is best for your photographic needs? There are a few points to consider, and we’ll step through some of the main ones here.

Technical differences between a Mirrorless and a DSLR camera

The term ‘mirrorless’ comes from the fact that the complex system of mirrors in a DSLR is completely removed from the camera.

These mirrors are there to direct light coming through the lens, up and out through the viewfinder, so that the photographer can frame their shot.  

The mirrors also direct light on to the dedicated Auto Focus sensor, as well as the Auto Exposure sensor. This means that you have a dedicated purpose-built component to control autofocus, and a purpose-built component to control auto exposure. 

Comparison between a Mirrorless and a DSLR camera from the inside

In a mirrorless camera, these components are removed, along with the mirror-box. By removing the mirrors the camera becomes smaller and lighter however this does present a challenge, because a substitute for the Auto Focus and Auto Exposure sensors needs to be found. Mirrorless cameras give that job to the imaging sensor, meaning that it has to do multiple jobs.

You’re probably wondering what the impacts of these technical differences are. Wonder no more!

Size and weight

Mirrorless cameras were created to achieve a smaller and lighter camera, while still offering high quality images. In order to create the smallest camera possible, manufacturers analyse every component as a possible point of reduction. The components that have the greatest effect on overall size and weight are the imaging sensor and the lenses. With a smaller imaging sensor a camera can have a smaller lens mount, lenses, and body overall. On the flip side, larger imaging sensors mean everything has to be physically bigger.

The 2 most common sizes of imaging sensor are the Full Frame sensor and the APS-C sensor, sometimes referred to as a crop sensor. Canon’s EOS DSLR range features cameras with either Full Frame or APS-C sized sensors. Generally speaking a Full Frame camera will be more expensive than an APS-C camera as the imaging sensor is one of the most expensive components of the camera.

Canon’s EOS M range of Mirrorless cameras offer a great balance between size, weight, and value for money which is why they’re in the sweet-spot for using our APS-C sized imaging sensor.

APS-C sensors are what we use in all our entry to mid-range DSLR cameras—such as the EOS 80D—and now our EOS M Mirrorless range.

Canon’s EOS R series feature Full Frame sensors. Whilst physically smaller than Full Frame DSLR cameras, the focus of developing EOS R was not to make a smaller camera. EOS R series was born from the pursuit to make lenses which were not previously possible, delivering the highest quality images therefore a full frame sensor is featured in all EOS R models.

Image Quality

We believe mirrorless cameras should offer the same quality as DSLR cameras, just in a smaller package, hence the choice of either an APS-C sensor (EOS M) or a Full Frame sensor (EOS R). Specifically, this means great low light performance, image detail, and colour, as well as shallow depth of field.

Image taken using EOS R

Camera performance

In use, the difference between Mirrorless and DSLR cameras, stems mainly from how you frame your subject.

For example, an EOS DSLR will always have an optical viewfinder, as well as an LCD screen. Canon Mirrorless cameras will always have an LCD screen, but not necessarily a viewfinder. If there is a viewfinder it will be an electronic viewfinder.

As you look through the viewfinder of a DSLR camera, you are seeing exactly what the lens sees, in real time, as the light is bounced up and out through the eyepiece. In a Mirrorless camera, you look at what the imaging sensor is seeing, regardless of whether you are viewing it through the LCD screen, or an electronic viewfinder. Many photographers feel that the optical viewfinder featured on an EOS DSLR enables you to have a closer affinity with your subject and feels more responsive.

A Mirrorless camera shows you exactly what will be captured; this ‘what you see is what you get’ approach can give you a better idea of how the final image will look. Significantly, this makes it easier to get to grips with operating the camera in manual mode, as you will get a real-time indication of how the exposure will look. EOS DSLR cameras can also achieve this when operated in Live View mode using the LCD screen—giving you the best of both worlds.

DSLR cameras excel at tracking moving subjects.

Advanced algorithms in the dedicated Auto Focus system of an EOS DSLR can actually track a moving subject, and will be able to predict where it will be in the split second the shutter button is pressed.  Even in high-speed shooting mode, the camera will constantly focus the subject. The premise behind this type of auto-focuscalled Phase Detectionis that the camera knows exactly how far to move the focus mechanism in the lensand in which directionto achieve focus.

Photo of bicycling by Maria Boyadgis 

Canon EOS R and EOS M Mirrorless cameras feature an advanced system call ‘Dual Pixel CMOS AF’, whereby every pixel acts as a phase detection sensor. This technology continues to advance and has considerably reduced the time it takes to focus, even in situations where the subject is moving.

Another thing to bear in mind with mirrorless cameras, and a characteristic of their reduced size, is that the batteries tend to have much lower capacity. As a very rough approximation, you can expect to capture twice as many shots on a DSLR than you can on a Mirrorless camera. Of course this problem is solved by grabbing an extra battery from your favourite camera store.

Lens choice

No matter which Canon EOS camera you choose, you will be able to use over 80 Canon EF lenses.  There is a huge range to choose from whether you are looking for a general purpose zoom or travel lens, or shooting something more specific such as portraits, landscapes, macro, sports or wildlife.


When choosing the right Canon lens for your Mirrorless camera, you just need to be aware of a couple of things.

Firstly, the reason why most people choose an EOS M mirrorless camera, is because of their reduced size.

We’ve created the EF-M range of lenses built specifically for the smaller lens mount of EOS M series cameras, they are the smallest lenses in the Canon rangebut still offer superb quality.

Canon’s new EOS R series of Full Frame Mirrorless cameras is built for a new lens range, the RF series. Removing the mirror assembly from the camera design enables the RF lenses to be placed closer to the imaging sensor which opens up new lens designs which were not previously possible such as the RF 28-70mm f/2.0L which features an unprecedented f/2.0 maximum aperture throughout the zoom range.

Compatibility is a key focus across Canon’s lens range. If you are moving to mirrorless from a Canon DSLR camera and wish to use your EF or EF-S lenses, you will need to purchase an lens Adapter.

The lens adapter for EOS M cameras is called EF-EOS M, whilst there are 3 choices of lens adapter for the EOS R series:

• EF-EOSR standard adapter
• EF-EOSR control ring adapter, featuring a lens control ring allowing intuitive selection of shutter speed, aperture or ISO
• EF-EOSR filter adapter, featuring either an ND or circular polarizing filter built in to the adapter

lens range compatible with mirrorless cameras

Canon EOS front on angle image


To capture video on a Canon EOS DSLR, you need to switch to Live View mode, so focusing and tracking performance will offer a very similar experience to shooting with a Canon EOS Mirrorless camera. The main consideration you should be aware of, is the type of auto-focus system the camera uses. For example, newer EOS DSLR and Mirrorless cameras use ‘Dual Pixel CMOS AF’ which offers superb Auto Focus performance, a huge advancement from previous generations.

One advantage of Mirrorless cameras which feature Electronic viewfinders (EVF’s) is that you can use the viewfinder whilst shooting video. In tricky lighting conditions this is often better than using the built in LCD screen. Unfortunately you are unable to use the Optical Viewfinder of a DSLR camera when shooting video.

Finally, you should also consider the often overlooked subject of audio capture. Canon EOS DSLR and Mirrorless models will both be able to capture audio using the built in microphone. For best performance however, you should think about adding an external microphone. This will do a better job, particularly with spoken dialogue. However, you need to double check that your chosen camera has the required 3.5mm microphone port. The same goes for the headphone socket, which can be used to monitor sound on the fly.

For more information to help you decide which camera is right for you, click here.

Mirrorless Cameras: Sample Image Gallery
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