If you're sold on the idea of a mirrorless system camera, how do you choose one model that's just right for you? We can boil that decision down to three simple questions:
1. Which form factor do you prefer?
2. Do you want to buy extra lenses?
3. What is most important to you?
An easy way to think about selecting a mirrorless system camera is simply which form factor you prefer. Do you want something really slim and easy to carry, or are okay with something a little bigger? Or do you prefer a mirrorless camera which handles like a DSLR camera, with a viewfinder and the familiar hand-grip?
The slimmest and smallest mirrorless system cameras are also, not coincidentally, the most basic and affordable mirrorless system cameras. Think the sensor of a mirrorless camera with the handling of a digital compact. While these options are good for those on a budget, the smaller sizes don't always handle well. While the cameras are smaller, the lenses are the same size, so when you fit them on the camera's heft can feel front heavy.
Examples of these cameras include the Olympus E-PM1 and the Panasonic GF3.
A chunky but comfortable size is where most mirrorless system cameras are at, and it's really the sweet spot in mirrorless system camera design.
Sure, they're bigger than your standard compact camera and aren't pocketable, but they'll still fit nicely in a normal bag and are light enough to comfortably carry. And they're lighter and smaller than any DSLR camera for sure. The other key point about this size of mirrorless system camera is that they don't skimp on the manual controls which enthusiasts love. So you can still shoot manually, like a DSLR camera, with a small camera body. And when you mount lenses on these cameras, the heft usually feels just right.
Examples of these cameras include the Nikon 1 V1, the Olympus E-P3, the Panasonic GX1, the Samsung NX200 and the Sony NEX-5N.
If you don't mind going bigger and love the handling of a DSLR with a built-in viewfinder, you can opt for the DSLR-like mirrorless system cameras.
The viewfinders in these mirrorless cameras is different though, they're electronic instead of optical like DSLR cameras, but advances in EVF (Electronic Viewfinder) technology has made them pretty responsive. While they may not be as clear as optical viewfinders, especially in low-light, an added advantage is that they can display digital information, so you can see more shooting info on the EVF.
Examples of these cameras include the Panasonic GH2 and the Olympus EM-5.
The fun with mirrorless system cameras is that, like DSLR cameras, you can swap lenses and increase your repertoire of shots, from wide-angle photographs of landscapes to macro shots of insects. But there are also users who buy mirrorless system or DSLR cameras and never go beyond the kit lenses which came in the box. If you're one of those users, then you can skip this section and go to the next one below.
If, however, you want to buy more lenses, then you have a little more to think about.
Before we go more into mirrorless system standards and their lenses, you may be wondering what the big deal is about getting more lenses anyway. The simple answer is that more lenses allow you to shoot more expressively with better results.
For example, have you ever seen a photograph shot with a DSLR camera which had a sharply focused subject but a beautifully blurry background? You can get that effect with what's known as a wide-aperture lens (even though there are compact cameras with wide-aperture lenses, you won't be able to get the same richly blurred backgrounds with their smaller image sensors). Similarly, you can also grab wide landscapes with wide-angle lenses, or get zoom amazingly far with telephoto lenses. Lenses enhance the camera you already have, letting you shoot more creatively than if you only had a single lens.
Even though we call them mirrorless system cameras, there really isn't a single mirrorless system. Instead, there are several (seven today) mirrorless systems in the market today, each manufactured by the different camera companies. Let's make it simple and call them mirrorless standards instead of systems in this article.
The first and most established mirrorless standard is Micro Four Thirds. Launched in 2008, the Micro Four Thirds standard has the benefit of having two companies, Panasonic and Olympus, put their weight behind it. Because of that, it's the standard today with the largest collection of native lenses, twenty five at the time of this writing. The other mirrorless standards are standalone standards; each is supported only by the company which created it. Samsung's NX standard has the second largest collection of lenses, ten in total. Sony's NEX standard has seven lenses. Nikon's 1 standard has four. The new Fujifilm X standard has three prime lenses at launch. There are other standards like the Pentax Q and Ricoh GXR, and some people also place Leica's digital M-series as mirrorless system cameras.
The reason why you need to know this is because if you're a lens aficionado then it's more likely you'll prefer the standard with a wider native lens selection, which, at the moment is Micro Four Thirds.
Adapters are available for some of these standards, allowing you to mount other lenses onto the cameras, but results are varied. With some adapters you'll still get access to auto-focus but with others you'll have to shoot manually. Some adapters are slimmer, while others add considerable size.
Again, a wider selection of lenses isn't important if you don't want to get any beyond the lenses which come with the camera. If that's the case, then simply look at the form factor you prefer and consider what's most important to you (see below).
Here's one last tip for the enthusiasts: Fixed-aperture zoom lenses, like the classic 24-70mm f/2.8, are almost non-existent in any mirrorless standard, but there are quite a few prime lenses. If you're keen on carrying a few primes, then see if each standard covers the ranges you want. Right now the most comprehensive is Micro Four Thirds', with eight native primes.
What is most important to you when choosing a camera? Is it how easy it is to use? Is it how good the image quality is? Is it how fluent the manual controls are? Or is affordability the most important? We might think that they are all equally important factors but usually there are a couple which are more important than others.
If affordability is the most important factor then you'll be looking at the slimmest and smallest mirrorless system cameras. But if you're talking about minimizing cost while still getting the most bang for your buck, then consider spending a few hundred more for the compact mirrorless system cameras which are a little bigger, but will usually give you a few more features, handle better and are better built.
You're in luck then, as most mirrorless system cameras are built with ease of use in mind. Even though a lot of them have manual modes built in, all of them have automatic modes for the everyday user.
Panasonic's iA system deserves special mention here, as it's just a simple button away and is excellent. Nikon's 1 series cameras have exceptionally fast and accurate auto-focus systems, which will work well for parents who want to photograph their active kids. Some mirrorless system cameras have touch-screens, like Panasonic's GX1 and Olympus' E-P3, which let you simply tap to focus and shoot.
Image quality usually corresponds to sensor size, the larger the image sensor the better the image quality. Within the mirrorless standards mentioned, the Nikon 1 series has one of the smallest sensors (but which is still larger than any compact camera sensor). It's followed by the larger Micro Four Thirds sensor, and then the Sony NEX and Samsung NX cameras which have APS-C sized sensors. APS-C sensors are the same sensor sizes you find in entry-level and mid-range DSLR cameras. At the moment, the Sony NEX cameras offer the best image quality out of all mirrorless system cameras.
There are drawbacks of course. Because the sensor size is larger, the cameras are also larger. Sony has done a remarkable job of keeping their NEX cameras small, but their lenses are large, larger than comparable Micro Four Thirds cameras. This adds to the overall bulk you'll have to carry. And a larger sensor doesn't always guarantee a better quality image sensor, so it helps to check up on reviews of the camera you want to buy.
While some buy a mirrorless system camera to upgrade from a compact camera, some buy one to downgrade from a DSLR camera for a smaller, lighter companion. Even then though, these users don't want to miss out on the manual controls they've grown used to on their DSLR cameras.
In that case, these users will want to look at the compact to the DSLR-like mirrorless system cameras. You'll be looking at the compact mirrorless cameras to the DSLR-like mirrorless cameras - they will both usually have good manual handling but the one difference is that the DSLR-like cameras come with electronic viewfinders. Some mirrorless cameras are crossing the line between consumer and professional, for example the Panasonic GH2 can record uncompressed HD video and audio to an external recorder, while the Olympus E-P3 can trigger remote flashes wirelessly.