Mirrorless compact system cameras are gaining ground on traditional digital SLRs. The top models now have autofocus systems that can match or even beat the speeds of those in digital SLRs, and many have EVFs (electronic viewfinders) with very high resolution and high refresh rates – they can almost match the visual quality of an SLR's optical viewfinder, and they can show a much wider range of shooting information and camera settings. They can even show you what your picture will look like with the current settings, filter effects or picture styles applied.
You can check out the latest camera reviews on our cameras home page, but we've also picked out our top advanced mirrorless compact system cameras in this guide.
If you're not sure this is what you need, check out our guide to the best compact system camera for your needs and the features to look for.
All of these cameras push back the frontiers of mirrorless camera technology, and they all have the potential to topple the traditional digital SLR camera from its top spot in the digital camera market.
1. Sony A7R II
Sony's top full-frame mirrorless camera challenges the best DSLRs
Sensor size: Full frame | Resolution: 42.4MP | Viewfinder: Electronic | Monitor: 3-inch tilting screen, 1,228,800 dots | Maximum continuous shooting rate: 5fps | Maximum video resolution: 4K
The Alpha 7R II is a really good all-rounder that combines a compact body with a level of resolution only beaten by the Canon EOS 5DS – and it weighs a heck of a lot less. Many pros are starting to look seriously at compact system cameras, and while the A7R II's AF system may not quite match that of similarly priced SLRs, it's more than good enough for general photography, and it comes with the kind of high-end 4K video capabilities that professionals will look for. The only thing missing is a DSLR-rivalling lens range, but Sony is promising 20 directly compatible optics available by early 2016.
Read the full review: Sony Alpha A7R II
2. Olympus OM-D E-M5 II
It may not be the 'pro' model but the E-M5 II is a real pocket powerhouse
Sensor size: Micro Four Thirds | Resolution: 16.1MP | Viewfinder: EVF | Monitor: 3-inch articulating display, 1,037,000 dots | Maximum continuous shooting rate: 10fps | Maximum video resolution: 1080p
The Sony A7R II has the best of everything with a price to match, but in its own way the Olympus E-M5 II is equally impressive. Its pixel-shift 40Mp High Res mode produces detail far beyond the sensor's native resolution (though only with static subjects), its 5-axis image stabilization for both stills and movies is perfect for 'run-and-gun' style videography, and it has some clever and exciting low-light exposure modes. The E-M5 II is small yet perfectly formed – and although it might look like a consumer camera its features outdo those in the range-topping E-M1.
Read the full review: Olympus OM-D E-M5 Mark II
3. Panasonic GH4
The GH4 is inventing a brand new kind of stills/video hybrid camera
Sensor size: Micro Four Thirds | Resolution: 16.1MP | Viewfinder: EVF | Monitor: 3-inch tilting screen, 1,036,000 dots | Maximum continuous shooting rate: 12fps | Maximum video resolution: 4K
The GH4 has been a real slow burner. While cameras like the Sony A7R II and Olympus E-M5 II feel like stills cameras with (albeit excellent) video capabilities added on, the GH4 has forged a reputation as a brilliant hybrid designed equally for both. Its 4K video capabilities are becoming legendary amongst professional film-makers and the new GH4R variant adds unlimited 4K shooting and professional V-Log high dynamic range recording. A paid-for update can add V-Log recording retrospectively to the existing GH4, too. The GH4 is also a very good stills camera capable of shooting top-quality 16Mp images at up to 12 frames per second or 8MP stills from 4K video shot at 30fps. All this processing power made the GH4 expensive initially, but prices have been dropping steadily, which bumps it up a couple of places on our list.
Read the full review: Panasonic Lumix DMC-GH4
4. Samsung NX1
The NX1 has power and performance but will it be taken seriously?
Sensor size: APS-C | Resolution: 28.2Mp | Viewfinder: EVF | Monitor: 3-inch tilting display, 1,036,000 dots | Maximum continuous shooting rate: 15fps | Maximum video resolution: 4K
The Samsung NX1 does everything right on paper, with an excellent 28-megapixel back-illuminated APS-C sensor, pro DSLR-beating continuous shooting at 15 frames per second, plus 4K video. It's tough, solid-feeling and weatherproof and built to appeal to serious, even professional photographers. It also has a fast and highly sophisticated autofocus system with unique 'baseball' and 'jump shot' modes that fire the shutter at the perfect moment. But this is also where it starts to unravel slightly because this kind of feature feels like it belongs on an amateur snapshot camera, not one aimed clearly at experts. The other issue for the NX1 is lenses – Samsung does offer a modest selection covering most everyday needs, but to compete with big name DSLRs and Sony's mirrorless cameras, it needs more premium-quality fixed aperture zooms and prime lenses and, crucially, more support from third-party lens makers.
Read the full review: Samsung NX1
5. Panasonic GX8
The GX8 has the best sensor in the current Panasonic range, but it's pricey
Sensor size: Micro Four Thirds | Resolution: 20.3MP | Viewfinder: Tilting EVF | Monitor: 3-inch tilting screen, 1,040,000 dots | Maximum continuous shooting rate: 8fps | Maximum video resolution: 4K
Unlike the Samsung NX1, the Panasonic GX8 has nothing to prove, lens-wise, calling an extensive lens range using the same Micro Four Thirds mount as Olympus. You might expect its DSLR-style G-series cameras to get the best and latest tech, but actually it's the the box-shaped GX8 that's the first to benefit from Panasonic's new 20Mp Micro Four Thirds sensor – this has performed really well in our lab tests, putting it on the same level as a good DSLR. The GX8 also comes with 4K video and the ability to grab 8Mp stills from it (it's like continuous shooting at 30fsp). The rear screen is tilting and so, unusually, is the electronic viewfinder eyepiece. It's a very good camera, but the price is a sticking point. If this comes down a little, it will make the GX8 a very attractive choice for experts.
Read the full review: Panasonic GX8
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