Difference between DSLR & Mirrorless camera

The DSLR vs. mirrorless camera debate is a crucial one to consider when you're buying a higher level camera.

A few years ago, that debate would have raged around which is better, but these days it's better to consider which is best for you. That's an important question, because though the two types of camera have many similarities, they also have some big differences. 

On the similarities side, both allow you to swap out lenses and accessories, which makes them more versatile than point-and-shoot, bridge or instant cameras. In terms of differences, mirrorless cameras tend to be smaller and lighter, on account of not having a bulky mirror inside, while DSLRs typically have more lenses to pick from. 

So, which type of camera is best for you? Read this DSLR vs mirrorless guide to find out.

Mirrorless vs DSLR: Introduction

How do you make the right choice in the great mirrorless vs DSLR camera debate? Things have certainly changed in the decade since mirrorless cameras first arrived on the market, but our in-depth guide is here to give you all the answers.

These days, mirrorless cameras are now the default style for the world's biggest camera brands – even the doyens of DSLRs, like Canon and Nikon. Back in the early days of the format, the decision was pretty simple – if you were a pro, you tended to pick up a DSLR. Hobbyists and amateurs, who were more bothered by weight and portability, would instead lean towards their mirrorless counterparts.

But now the roles are somewhat reversed. The latest and greatest technology is now found in mirrorless cameras. And if you’re an entry-level user, you might be more likely to go for a cheaper DSLR, given they remain the most affordable way to get a camera with a built-in viewfinder. 

For those in between beginners and pros, there's now more choice than ever before, which can make choosing the right camera tech for you somewhat tricky. But fear not, that’s where we come in.

Let’s start with the basics and look at the key differences between the two types of cameras. The key is in the names. DSLR stands for Digital Single Lens Reflex, which works by the light hitting a mirror angled at 45 degrees. That light goes straight up into an optical viewfinder which allows you to see precisely what the lens is looking at. This is a true optical path, with no digital processing in the middle. 

When you’re ready to take a photograph, that mirror moves out of the way – to reveal the image sensor – and if you’ve used one in the past, you’ll be familiar with the satisfying (but fairly loud) noise it makes as it does so. 

By contrast, mirrorless cameras – you’ve guessed it – don’t have a mirror. With these cameras, the light passes through the lens and straight onto the sensor to be processed. It’s then displayed either on the monitor on the back of the camera, or in the electronic viewfinder (EVF), which is in essence a very small monitor. This time, when you take a picture, the camera is simply recording what is on the sensor at that moment in time. 

DSLRs use the same technology as their film counterparts, which have been around for decades. They’re very familiar for anybody who has been serious about photography in recent years. Legacy companies such as Canon, Nikon and Pentax have been making them for all those years and so have a lot of experience to draw from. 

These days, relatively few new DSLRs are introduced to the market, but there’s still plenty you can buy. They tend to have great handling, offer fantastic image quality and one advantage that doesn’t look set to go away for a while yet – extremely impressive battery life. 

By taking away the mirror, mirrorless cameras give you several advantages (and very few disadvantages). The key one is that, since they don’t need that big clunky mirror setup, they can be smaller and lighter than their equivalent DSLR counterparts. 

Some of the tasks of the camera, like autofocusing, can take place on the sensor itself, leading to super-quick focusing speeds. Speaking of speed – with no mirror to move out of the way, frame rates aren’t limited so much by physicality. Mirrorless cameras routinely offer at least 10fps, with some high-end models delivering 20fps or 30fps at full resolution, with continuous autofocus between each shot. 

In the beginning, mirrorless cameras tended to use smaller sensors than DSLRs. But now, the most popular sensor size in these models is full-frame, with Sony, Nikon, Canon and Panasonic all producing this type of camera. APS-C is also a common sensor size, for both mirrorless and DSLR. All of this means that there’s no generally discernible difference between outright image quality in DSLRs and mirrorless cameras, no matter which you choose to go with.

The electronic viewfinders found on early mirrorless cameras weren’t particularly great, being low in resolution and slow. But over the years the technology has advanced so much that many photographers now prefer the super high-resolution viewfinders on the current crop of high-end mirrorless cameras. They show a truer reflection of what your final image will look like, as well as allowing you to see a preview of your image after you’ve shot it.

All of this makes it sound like mirrorless is the obvious winner – and while the fact that barely any new DSLRs have been announced in the past 12 months might seem to back that up, there are still some advantages of the older technology. 

What are the main differences between DSLR and mirrorless cameras? 

Digital single-lens reflex (DSLR) and mirrorless (often referred to as compact system) cameras are both interchangeable lens cameras, with features for more advanced photography. There are ranges of models available for each, from those aimed at entry-level photography enthusiasts to professionals. Both cameras typically have big sensors, allowing them to let in more light and capture more detail than a standard digital camera.  A key difference between the two lies in the way image previews are displayed:  DSLR cameras have a reflex mirror inside them, which bounces light up into the optical viewfinder With mirrorless cameras, light goes directly into the image sensor. Viewfinders on mirrorless cameras are electronic and show the same preview of the image that you'd see on the LCD screen.  While what you see through an electronic viewfinder (or on an LCD screen) is very similar to what you'd see through an optical monitor, there are some subtle differences.