If you haven't bought a camera within the last couple of years, you'd be forgiven for being a little confused when you walk into your local camera store. There's a relatively new category of cameras that aren't point-and-shoot compacts and aren't digital SLRs. Mirrorless digital cameras take the best parts of a DSLR and shoehorn them into an almost-compact-camera sized chassis, giving you a portable shooter that can capture photos you'd be happy to share online or print.
What Does 'Mirrorless' Mean?
You might have seen a mirrorless camera talked about online before and just not realised it -- they go by a few different names. They're alternately called compact system cameras (CSCs), interchangeable lens cameras (ILCs), or electronic viewfinder interchangeable lens cameras (EVILs); whatever the name, though, they're defined by one shared characteristic -- they all work with different interchangeable lenses like a digital SLR, but don't have that system's bulky internal mirror -- hence the mirrorless name.
There are a few different interchangeable lens mirrorless camera systems, from all the major camera brands. Sony has its Alpha E-mount mirrorless cameras, Panasonic has LUMIX G, Olympus has OM-D and PEN, Nikon has its small-sensor 1 Series.
What Can Mirrorless Cameras Do?
Despite being smaller, lighter, mechanically simpler, and more high-tech than digital SLRs, mirrorless cameras are just as powerful when it comes to actually taking photos. They're built using much the same principles, so they're easy to understand -- you still get a lens mount and lens at the front, digital sensor inside, a big LCD screen and/or viewfinder at the back, and a comfortable hand- and thumb-grip with shooting controls.
The big difference between a mirrorless camera and a DSLR is that when you turn a mirrorless camera on and look through its viewfinder, you get an electronic read-out of what the sensor is seeing, rather than looking optically through the lens via a light-bouncing prism. That electronic readout lets a mirrorless camera show you exactly what photo you're about to capture, along with the added versatility of boosted brightness in low light and the ability to see a bunch of shooting information -- the stuff that affects your image capture -- in real time.
Smaller And Sleeker Bodies
Because they're entirely digital, mirrorless cameras have fewer moving parts than DSLRs and can be made both more portable and more sturdy. A pint-sized camera like the Sony a6000 has the same size image sensor as a Canon or Nikon semi-professional digital SLR, along with a bunch of high-end features like super-fast continuous shooting and built-in Wi-Fi, but is a third of the size and weight.
Even larger and more powerful mirrorless cameras like the Sony a7, which has a massive full-frame image sensor like the kind found in a super-high-end professional DSLR, are still small. Because the technology is cutting-edge, with a built-in OLED viewfinder instead of a bulky optical prism, when you pick up a high-end mirrorless camera you can feel that everything is packed into the smallest possible space. You don't sacrifice usability though, since these top-end mirrorless bodies have dual control wheels and customisable function buttons and dedicated exposure dials and everything you'd expect from the best digital cameras.
Electronic Viewfinders For Perfect Framing
On mid-range and more expensive mirrorless cams, add-on or integrated electronic viewfinders give you a live read-out of what the camera's digital imaging sensor is seeing through the attached lens. These tiny LCD and OLED screens are incredibly detailed and engineered for close viewing, so you're able to put your eye directly to the camera just as if it were an old-school optical finder. If you don't want one, of course, you can buy mirrorless cameras without electronic viewfinders and you can always rely on the big rear LCD screens for framing your photo as well.
Electronic viewfinders, or EVFs, have recently made big improvements in quality, in the depth of their contrast and black levels and the number of pixels on their displays. They're increasingly approaching the level of real-world detail that you'd see through a glass optical viewfinder, but they also offer a huge amount of customisation and adjustability. In low light, where you might not be able to see your subject through an optical finder, an EVF can boost its brightness and increase the read-out from the digital sensor to give you a view that's just as bright as in daylight.
Smaller, Faster And Brighter Mirrorless Lenses
Because mirrorless cameras don't have a bulky internal mirror, they can be optimised for camera lenses that sit incredibly close to the digital imaging sensor, improving fine-image detail and overall picture quality. Mirrorless camera lenses are smaller than their DSLR-style counterparts, but don't cede any ground in terms of brightness or maximum light transmission. In fact, an equivalently-sized lens for a mirrorless shooter will let in more light than its DSLR counterpart, because there's less compromise necessary in the optical design.
Mirrorless cameras also allow for compact, high quality prime lenses that are just as good as anything you'll find from the old film camera era. Plenty of affordable zoom and prime lenses are available from most mirrorless camera brands tailored to their specific cameras, but some manufacturers also have professional-grade mirrorless lenses for their high-end cameras as well. The latest and greatest mirrorless cameras also have a huge range of optical adjustments built-in to their live sensor read-outs, letting lenses become even more compact and portable while still maintaining good image quality.