Early models fulfilled the process of image quality that approached that of an SLR in a smaller form factor, but suffered from slow autofocus and limited burst shooting. Those days are, for the most part, over. Entry-level models can still be a little pokey in terms of focus, but as soon as you get into the midrange you’ll find that many models match or exceed SLRs in focus speed, especially when it comes to video. Because of their slim design, these cameras give you the option of buying modern native lenses or mounting older SLR and rangefinder lenses via a simple adapter.
The first models to hit the market were part of the Micro Four Thirds system, a mount and lens system that’s shared by Olympus and Panasonic cameras. Those were sooned joined by Sony and Samsung, and later by Pentax, Fujifilm, and Nikon—and each of those companies uses its own proprietary lens system. Missing from the list is the brand that is synonymous with cameras in many minds, Canon. Its EOS M debuted to a cool reception in the US. Canon still sells its mirrorless system in other countries (the EOS M3 is the latest iteration), but not in the States.
Because development of these systems has not been tied to legacy systems that are built around 35mm film, sensor sizes vary. Pentax builds mirrorless cameras like the Q-S1 with 1/1.7-inch image sensors, the same size as you’ll find in better point-and-shoot cameras. The Nikon 1 and Samsung NX Mini systems use 1-inch image sensors, which are a bit larger but still pretty small when compared to sensors that you’ll find in D-SLRs.
The Micro Four Thirds system is next up in size. If you want to get an idea of how the field of view of Micro Four Thirds lenses compares with 35mm film, you’ll want to double the focal length; a 25mm lens on a Micro Four Thirds camera matches the field of view of a 50mm lens on a full-frame D-SLR. The sensor aspect ratio is also different—it’s 4:3, like an old TV, rather than the 3:2 ratio of APS-C and full-frame systems.
Like most consumer D-SLRs, systems like the Fujifilm X, Leica T, Sony E, Samsung NX, and Canon EOS M use APS-C image sensors. They enjoy a 1.5x multiplication factor compared with full-frame cameras, a figure that anyone who has shopped for an APS-C D-SLR is familiar with.
Sony is the only company producing autofocusing mirrorless cameras with full-frame image sensor. Its Alpha 7 series currently consists of four models. They use the same physical lens mount as APS-C Sony bodies, and if you mount a lens that’s designed for an APS-C Sony body the image will automatically be cropped to compensate for the smaller field of view produced by the lens.
We make the autofocus distinction with Sony because Leica’s M system of full-frame rangefinder cameras fits the mirrorless bill as well. M rangefinder cameras have been around longer than most SLR mounts, for more than 60 years, and have long utilized a fixed optical viewfinder with an optical rangefinder to focus and frame shots. The latest digital iteration, the M (Typ 240), adds Live View and video recording, but in many ways it still handles like a camera from the 1960s. Old school shooters appreciate that.
Mirrorless cameras are better than they’ve ever been before. Most models offer excellent image quality, quick autofocus, and a wealth of lens options. But if you’re not ready to make the move away from a traditional optical viewfinder you’ll still want a D-SLR. Check out our D-SLR Buying Guide for a look at some of the best standard-size interchangeable-lens cameras. And hit our Digital Cameras Product Guide for the latest camera reviews and The 10 Best Digital Cameras for the top-rated models.
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Olympus OM-D E-M1
$1,399.99, body only
A$944.10 at CameraSkyWith gorgeous images—even in low light, incredible speed, and a wealth of high-end features, the Olympus OM-D E-M1 is the best Micro Four Thirds camera that money can buy. It’s an easy Editors’ Choice award winner.
Leica M (Typ 240)
$6,950 list, body only
$6,500.00 at AmazonThe Leica M (Typ 240) is the camera that many a rangefinder photographer has been waiting for. It fixes many of the issues of previous models, but it doesn’t come cheap.
Olympus OM-D E-M10
$699.99, body only
$449.00 at AdoramaThe entry-level mirrorless OM-D E-M10 is another winner in Olympus’ OM-D series. Its image quality, speedy performance, and built-in EVF earn it Editors’ Choice honors.
$1,499.99, body only
$1,228.45 at AmazonThe Samsung NX1 has it all: quick focus, 28-megapixel resolution, 4K video, Wi-Fi, and a weather-sealed design. It’s our Editors’ Choice for high-end mirrorless cameras. Read the full review ››
Sony Alpha 6000
$649.99, body only
$448.00 at B&H Photo-VideoThe Sony Alpha 6000 focuses instantly and shoots at 11.1fps. Its image quality matches its speed, making it our Editors’ Choice.
Sony Alpha 7 II
$1,699.99, body only
$1,498.00 at AmazonThe Sony Alpha 7R is a full-frame mirrorless camera with an amazing 36-megapixel image sensor. It’s not quite as fast to shoot as its twin sibling, the Alpha 7, but its image quality earns it our Editors’ Choice award.
$1,299.95, body only
Best Price at AmazonThe Sony Alpha 7R is a full-frame mirrorless camera with an amazing 36-megapixel image sensor. It’s not quite as fast to shoot as its twin sibling, the Alpha 7, but its image quality earns it our Editors’ Choice award.
$1,199.95, body only
Best Price at AmazonThe Fujifilm X-Pro1 is a top-notch mirrorless camera that is sure to appeal to optical viewfinder fans that are put off by the high price of Leica rangefinders.
Panasonic Lumix DMC-GM1
$749.99 with 12-32mm lens
$469.95 at AmazonThe Panasonic Lumix DMC-GM1 is the smallest interchangeable lens digital camera you can buy. It’s not as full-featured as some other models, but you can’t argue with its size or performance.
Sony Alpha 3000
$399.99 with 18-55mm lens
$279.99 at GrouponThe mirrorless Sony Alpha 3000 cuts a lot of corners to hit its low $400 asking price, but there are no compromises in image quality.