Mirrorless Cameras vs DSLR Cameras: What's the Difference?

So you're considering a new camera, or perhaps it's time for an upgrade, and you've arrived at the single biggest question any rational human would ask in 2018. Do you go with the latest and greatest or the tried and true? DSLR or mirrorless? It's a big decision and your money is on the line so let's talk about mirrorless cameras vs DSLR cameras and find out what the differences really are.

A Bit of DSLR History

Digital cameras have been around for quite a while and it used to be common knowledge that anyone who was serious about photography bought and owned a DSLR, until recently. A DSLR is what the pros use and the technology pre-dates digital. SLR stands for Single Lens Reflex and refers to the flipping mirror mechanism that allows its user to see through the lens while composing a shot, flipping up out of the way when the shutter button is pressed to allow the light in making the exposure. This technology has been around since about 1933 and has proven to be reliable.

The D in DSLR was tacked on after the first fully integrated DSLR was introduced in 1999: the Nikon D1 (with a price tag over $30,000). From there, digital slowly displaced film once these cameras eventually became more affordable. Later, the consumer market became saturated with Canon Rebels, Nikon D variants and a few other brands like Pentax and Sony. The DSLR was king and largely still is. The DSLR is the most common form of interchangeable lens camera and the most familiar. But, things are changing.

A Bit of Mirrorless History

If you're into photography, you can't go a day without hearing something about mirrorless cameras. Stories of people switching from a DSLR to mirrorless system are everywhere. There's a lot of hype around this new technology. These cameras are commonly referred to as "mirrorless" because unlike the DSLR, they lack the flipping mirror that makes a DSLR unique. In place of that mirror is a live, electronic view of the world made available straight from the imaging sensor itself. More on that later.

Along with the designation of "mirrorless", these cameras are also less often called Electronic Viewfinder Interchangeable Lens cameras. Yep, EVIL cameras. It's no wonder the manufacturers haven't adopted that acronym. Another term is Mirrorless Interchangeable Lens Camera or MILC, but you won't really hear anyone call them that either. For now, we're stuck with mirrorless.

The first mirrorless camera came on the scene in 2004 and was made by Epson. Yeah, Epson. Weird, right? The RD-1 was the first and sported a Leica lens mount. Things really stepped up for mirrorless much later though. It wasn't until about 2013 that mirrorless cameras became more sophisticated and now, they're arguably on par with the venerable DSLR in terms of functionality. The dominant makers of mirrorless cameras are Sony, Fuji, Olympus and Panasonic. Notice any names missing there? Canon and Nikon anyone? More on that later.

Key Differences

Let's cut to the chase, shall we? What are the differences between mirrorless cameras and DSLR cameras?

Mirrors of course. As we discussed above, a DSLR has a mirror that reflects an image of the world through the lens into the photographers eye using a few components like the mirror, a prism and the optical view finder. This requires parts that move a lot. Every time you click the shutter button, that mirror has to flip up out of the way before the shutter opens. And it all works very, very quickly and frequently.

Optical view finders vs. electronic view finders. Unlike the real-life, reflected view a DSLR provides through the view finder, mirrorless cameras display that image in the view finder via an electronic image from the sensor, referred to as an EVF (electronic view finder). Since there's no mirror, an EVF is necessary to compose the image. There are some distinct advantages to an EVF over an optical view finder but that wasn't always the case.

Older mirrorless cameras had some pretty low resolution view finders, which meant the image you saw via the view finder would be grainy, noisy and pixelated. The refresh rate was also bad on older models, leading to choppy behavior when panning the camera. For these reasons, earlier EVF equipped cameras got a pretty bad wrap. And, they deserved it.

That's no longer the case. Although not every modern EVF is superb, most newer model mirrorless cameras are equipped with view finders that are so rich in pixel density, it's hard to tell you're not looking through an optical view finder. It's pretty impressive and has to be seen to be understood. They've come a long way. So what about those advantages? The biggest advantage of an EVF is that your eye is seeing exactly what the camera's sensor is seeing. This is a big deal.

Size and weight. This difference is debatable. DSLR cameras are usually big and pro-level cameras can be very big. You know someone is serious about photography when they have a big camera. Not really, but that's often the perception. Mirrorless cameras on the other hand are typically much smaller.

Even high-end pro-level mirrorless camera bodies tend to be much smaller than an equivalent DSLR. There are various reasons for this, but the lack of a mirror plays a large part in the size difference. Mirrorless cameras just don't need as much space for those moving parts. Here's a size comparison. DSLR cameras also require big, heavy lenses as well. It's not unusual for a full DSLR kit to weigh in at 15 to 20 pounds in a bag. That's a lot of weight. Mirrorless lenses tend to be smaller and lighter. This is nice for landscape and travel photographers who lug lots of gear around often. But not all mirrorless lenses are smaller.

As you get into faster lenses (those with wider apertures) the size and weight difference starts to become less significant. For example, Sony's newer, high-end G Master lenses are about the same size as any DSLR lens. It's just not physically possible to keep the size down for lenses that fast. But, most common, consumer grade mirrorless lenses are significantly smaller and lighter than their DSLR counter parts.

Adaptability. Because mirrorless cameras don't have to provide space for a flipping mirror, the image sensor is much closer to the lens. This short distance allows for better adaptability of lenses over DSLR cameras. What that means is, you can put all sorts of different lenses on a mirrorless camera using various adapters.

Many mirrorless shooters use vintage, manual focus lenses with great results. These types of lenses can be found really cheap too. Not only can vintage lenses be adapted, but modern DSLR lenses can be too. It's possible to use a Sony mirrorless camera with Canon EF glass using adapters. This is a great benefit of owning a mirrorless camera.

Autofocus. DSLR cameras and mirrorless cameras differ in how they handle autofocus. This used be a big advantage for the DSLR, but that's no longer true with modern mirrorless systems. A DSLR handles autofocus using a separate module. It's not using the imaging sensor for autofocus because the mirror blocks it.

Mirrorless cameras on the other hand don't require a separate module and use the imaging sensor for autofocus. Because of this, a mirrorless camera can use a hybrid form of focusing using both contrast detect and phase detect autofocus. This provides better accuracy and faster focusing when using large aperture lenses. It's also good for tracking moving subjects. What was once seen as a weakness in mirrorless cameras is quickly becoming one of its biggest strengths.

Video capability. Both camera types can shoot amazing video, but mirrorless has the advantage of no mirror standing in the way of the sensor when recording video. This isn't a huge advantage, but it does allow for less hassle when shooting video. For instance, you can't look through the view finder of a DSLR when shooting video, you have to use live view and look at the rear LCD screen.

With a mirrorless camera, you could use either the view finder or the LCD depending on your needs, which would come in handy on a bright day. Going back to adaptability, with a mirrorless camera, you can use many different types of lenses for video employing adapters for different effects.

Lens range. Here's a category where DSLR systems are the clear winner. Because they've been around for decades, the amount of lenses available for any major DSLR system is huge. A look at Canon or Nikon's impressive lens range will leave mirrorless shooters envious.

Most mirrorless manufacturers like Sony and Fuji are making strides releasing more and more lenses, but they have a long way to go to rival the more established DSLR lens range. Don't forget, you can still adapt most of these lens systems to a mirrorless camera though the performance won't be as good as a native mount.

Battery life. DSLR batteries last a long time. Like, a really long time. That's because the camera isn't doing much until you ask it to focus or take a picture. Mirrorless cameras on the other hand have a lot going on. Powering that EVF takes a ton of juice and all of the electronics that make the focusing system work so well are constantly draining the battery. On top of that, the camera bodies are smaller allowing for only low capacity batteries due to size restrictions.

You'll have to buy several extra batteries when toting your mirrorless camera on a trip of any length. Newer models increasingly have larger, higher capacity batteries but that also increases the size of the body. It's a trade-off. You'll get a lot more out of a battery in a DSLR than you will from a mirrorless camera.

Conclusion

Those are the key differences between DSLR and mirrorless cameras. Things are changing fast in the mirrorless world and newer more advanced cameras are being released all the time. Does that mean the DSLR is dead? Not at all. DSLR cameras are here to stay and have distinct advantages that will make them relevant even if mirrorless cameras end up becoming more popular. Among those advantages are durability, reliability, massive lens systems and optical view finders which many photographers prefer.

When making a purchase decision, you have two great options when it comes to interchangeable lens cameras. Much of your choice will come down to preferences and your priorities as a photographer. You could buy the latest mirrorless camera, or you may find that a DSLR suits your shooting style better. Either way, there are great deals to be had on both on the used market. Photographers are constantly trying new gear and switching systems as they feel out the different camera systems and brands making it a great time to buy used.

I have personally made the journey from a Sony DSLR system, to Canon DSLRs, to Sony mirrorless, to Fuji mirrorless and back to and older Sony DSLR. We photographers are fickle and we like our gear. But, that's what make this fun. There's always something new to try.

Author: Don Fitzsimmons
Co-Founder of Gear Offer, software developer and photographer.

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