The 10 Best Mirrorless Cameras
10. Olympus OM-D E-M10 Mark II
9. Fujifilm X-E3
8. Olympus Pen-F
7. Fujifilm X-T2
6. Olympus OM-D E-M1 Mark II
5. Panasonic Lumix GH5
4. Sony a7S II
3. Sony ILCE9 a9
2. Fujifilm GFX 50S
1. Sony a7R III
Through With The Looking Glass
On a traditional single lens reflex camera, or SLR, 'reflex' refers to the action of a small mirror in the camera body that sits behind the back element of the lens. That mirror reflects the light coming through the lens up into another series of mirrors, or, in more expensive cameras, into a complicated prism of glass called a pentaprism. Either way the light travels, it ends up in the eyepiece at the back of the camera through which you frame your image.
With that mirror in the way, however, it'd be impossible for the light coming through the lens to reach the film or the digital sensor (D-SLR indicates a digital version of the SLR design). Thus, all SLRs have a mechanism the reflexively pulls the mirror up and out of the way in a fraction of a second, just in time for the shutter to open and expose the sensor to light.
The problem with a reflexive mirror is that its movement creates vibrations in the camera, vibrations that decrease sharpness in your images. The reflex mechanism also necessitates that the camera be a certain depth to accommodate it, making your system bulkier and heavier.
The great challenge in designing a pro-level mirrorless camera was in the viewfinder. That mirror or pentaprism pathway was excellent at maintaining brightness and conveying real time framing of the scene before you without any lag. Early mirrorless viewfinders were always a step behind the action, making the cameras useless in sports, events, and other fast-paced shooting environments.
In the past few years, however, viewfinder technology has skyrocketed, mainly due to advances in smaller OLED displays. Now, not only do you get the full benefit of a sharp, bright OLED viewfinder that conveys info in real time, but you also can use that viewfinder to give you actual exposure feedback, so the brightness and contrast of the image you see is just what you'll get in your picture.
Altogether, these cameras result in a fast, informative shooting experience with no unnecessary vibration. What's more, some companies have utilized the room saved by the removal of the mirror to install on-sensor image stabilization that can correct for up to five axes of vibration, essentially doubling down on the original benefit of getting rid of the mirror.
Since mirrorless cameras are, in many ways, children of a marriage between early digital point-and-shoots and professional D-SLRs, some of their manufacturers have decided to make their camera bodies without any viewfinders, putting their focus on the quality of the viewing screen at the back of the camera body, while offering optional viewfinders for purchase.
A Good Time To Rethink Brands
There was a time in the dying art of film photography, and even in digital photography, when Nikon and Canon were the only significant players. In today's market, however, brand means less than ever.
Years ago, photographers found themselves locked into systems by the lenses they'd bought. They might own a $3,000 camera body, but they'd also own about $15,000 in lenses, so jumping ship was almost never an option. There are mirrorless systems on the market that work with all the old lenses, but most of them require adapters, and the use of giant lenses kind of flies in the face of one of the major advantages of mirrorless systems, which is that they're smaller.
If you've been shooting or a while, either in film or digital, and you're looking to make the jump to mirrorless, the chances are you're doing it to save on that size, to travel lighter than you otherwise could. You probably have a bevy of nice lenses that you don't want to just lose, or take a beating on in their resale.
The good news is that there are a couple of companies specializing in cross-platform adapters, meaning you can buy a camera off our list based on its technical specs without worrying about which lenses will or will not work with it.
You may be new to photography, however, and you want to start small without throwing a lot of money into moribund platforms. That's smart. You're lucky in that you have such a wide field of options, but that abundance can easily become confusing. Before investing in any camera system, you should know what you plan to shoot.
If you want to do street photography, taking clandestine pictures of unsuspecting people, you should aim for the smallest camera on our list that has a silent shutter. That way, you can take shot after shot without ever alerting your subject to your presence.
Event and sport photographers will want to put an emphasis on burst rate (maximum number of shots a camera can take in a second) and auto-focus speed. Nature and portrait photographers will want to know that there's an excellent selection of lenses for the system. Ten years ago, that would have sent photographers either to Nikon or Canon, but in the mirrorless market it's Fuji and Olympus who currently boast the best glass.
A Range Of Possibilities
While most people think of Sony, Panasonic, and Olympus when they think of the early pioneers of mirrorless, interchangeable-lens camera systems, it was a company known much more for printing pictures than for taking them that was first to the party.
In 2004, Epson created a digital rangefinder camera that utilized Leica's M-mount lenses. The 6.1 megapixel marvel, called the RD-1, was modeled after the Voigtlander Bessa 35, which was a film camera released in the late 1990s, and it came out costing consumers a hefty $3,000.
Now, I know a rangefinder is a mirrorless system to begin with, so making a digital rangefinder with interchangeable lenses is kind of a shortcut toward mirrorlessness, since there was no mirror to replace. But the idea of a digital camera with interchangeable lenses and no mirror was a total novelty, and the big brands we now associate with the mirrorless revolution all took notice, leading toward the relatively young, extraordinarily exciting products that continue to evolve.