What are compact system cameras

Our guide to compact system cameras – also known as Mirrorless Interchangeable Lens, ILC or EVIL cameras

Compact system cameras

What are compact system cameras?

The fastest-growing sector of the camera industry is one that many people have still never heard of, and many people still don't understand. Here we explain what Compact System Cameras are, why you might want one, and what's available...

Once upon a time, if you wanted to buy a digital camera you'd have the choice of a compact, a bridge (a compact with a high-magnification zoom) or a DSLR. The step up to a DSLR was a big one, literally. DSLRs are much bigger than compacts not only because they have much larger sensors, but because the viewing system that defines them as DSLRs - a 45° mirror reflecting up to a prism assembly and viewfinder eyepiece - takes up a lot of space.

Panasonic and Olympus were the first to realise that if you did away with the DSLR's optical viewing assembly you could still have a large sensor, and interchangeable lenses, but the camera could be much smaller, and the lenses could be smaller too. In 2008 Panasonic's Lumix G1 was the first camera with a DSLR sized sensor and interchangeable lenses to dispense with the mirror and prism, and swap the optical finder for an electronic one.

There is no agreed term for cameras of this type, but Compact System Camera (CSC) remains the most popular. MILC (Mirrorless Interchangeable Lens Camera) or simply ILC, or just "Mirrorless" are also used, while some prefer the acronym EVIL - for Electronic Viewfinder, Interchangeable Lens. Whatever they're called, every manufacturer now has at least one such camera of its own, with an accompanying range of lenses, but the original aims of the first CSCs - to provide the image quality and interchangeable lenses of a DSLR, but in a smaller package - no longer necessarily apply, as manufacturers have plumped for a wide range of different sensors, some of which are also used in compact cameras.

It's probably fair to say that today's definition of a CSC is a camera with interchangeable lenses but no mirror. Some have DSLR sensors, some have smaller ones, some have electronic viewfinders, others have no viewfinder - just the LCD screen.

Over the page we present a round-up of the different systems currently available, and what they have to offer.

Why buy a CSC?

Compact System Cameras are designed for buyers seeking a camera that offers lots of creative control, high image quality and the option to attach different lenses, but who don't want the bulk of a DSLR. Some are almost as big as a DSLR but offer a different user experience, due to the camera's shape and design, while others use a smaller sensor and put size and convenience above image quality in the list of priorities. (See facing page.)

Other factors need to be taken into consideration too. Most CSCs use the contrast detect method of focusing, which is slower than the phase detect method used by DSLRs. Combined with issues such as EVF refresh rates this makes most CSCs generally less suited to action photography, though there are some exceptions - the Nikon 1 system is blisteringly quick, and a few CSCs have phase detect pixels built into the sensor.

Some CSCs have viewfinders, but many offer just an LCD screen, which can make them more difficult to use in bright sun. A few have the option of a clip-on EVF at additional cost. Of those with a viewfinder it will be electronic, and these vary widely in resolution. Some cameras with EVFs are styled like mini DSLRs, while others follow more of a rangefinder style. Neither is better, it's down to personal taste. Finally, consider what other features are important to you. What about video? All offer HD video but bit rates and compression options vary, and only a few offer an external mic input. Do you want Wi-fi? This is becoming increasingly common on the newer models, and not only lets you publish online straight from the camera but often also enables you to control the camera remotely with a smartphone.

Sensor sizes and image quality

As a very general rule, bigger cameras have bigger sensors, which produce better quality images, so choosing a system entails first deciding how important image quality is compared with portability and convenience. It should be pointed out that even the smallest cameras are capable of producing high quality images to at least A4 at the lower ISO settings, and it's only when you go bigger than that, crop heavily, or use high ISOs that the more experienced, critical eye can discern the differences between the systems. So how do the sensor sizes vary between the camera systems? This diagram (below) illustrates the relative sizes of the sensors used by the different CSC manufacturers. The largest, APS-C, is the one used in most consumer DSLRs, while the Pentax Q7 uses a small sensor commonly used in some higher-end compacts.



Image above: The size of sensor used by a CSC varies from manufacturer to manufacturer, meaning image quality can vary greatly

Which CSC system?

Canon CSC systemCanon

Sensor size: APS-C
Current cameras: EOS M
Lenses in system: 3 (plus EF mount adaptor)

Canon was the last to launch a CSC and so far has only one camera, the EOS M, which uses the same 18MP APS-C sensor as many of its DSLRs. Its EOS style interface and touchscreen LCD make it an easy camera for Canon DSLRs to get to grips with and you can attach EF lenses, too, with an adaptor (which is just as well as at present there are only three EF-M lenses). Its downsides are slow AF that makes it unsuitable for action, and no viewfinder; but after an initially high launch price there are some deals available.

Fujifilm CSCFujifilm

Sensor size: APS-C
Current cameras: X-Pro1, XE-1, XM-1
Lenses in system: 8 (plus 4 more coming soon)

Fujifilm is targeting older pros and enthusiasts who probably hanker after a Leica but can't afford one. Fujifilm's X series of retro-styled CSCs take their design cues from the German marquee. The current models differ mostly in size and viewfinder type. The X-Pro1 has a hybrid finder that lets you switch between optical and EVF, the XE-1 has just an EVF, while the XM-1 has no viewfinder. All are great for manual control lovers, but auto scene modes and creative filters are there for those who want them.

Nikon compact system cameraNikon

Sensor size: 1 inch
Current cameras: S1, J3, V2
Lenses in system: 9 (plus F mount adaptor)

The Nikon 1 system is named for its one-inch sensor. Although much bigger than most compact camera sensors, it's a lot smaller than a DSLR's, but this makes the camera and lenses very small. The system is packed with ground-breaking technology, such as the ability to shoot full resolution shots at 60 frames per second, shoot video and stills simultaneously, and even begin capturing images before the shutter is fully depressed. The V series (currently the V2) is the only model in the range with a built-in EVF.

Olympus CSCOlympus

Sensor size: Four Thirds
Current cameras: OM-D E-M5, PEN E-P5, E-PL5, E-PM2
Lenses in system: 14 (45 MFT mount lenses altogether)

Olympus plundered its back catalogue for inspiration in its CSC design, with two retro-styled lines: the PEN series, based on the classic 1950's half frame PENs, and the OM-D, based on its classic OM film SLRs. The OM-D offers a built-in EVF while the PENs do not (though some accept an optional add-on one). All use the same MFT format sensor as Panasonic, and the MFT lens mount, which enables all Olympus, Panasonic and third-party MFT lenses to be attached.

Panasonic compact system cameraPanasonic

Sensor size: Four Thirds
Current cameras: GX7, GX1, GH3, G6, G5, G3, GF5, GF6
Lenses in system: 20 (45 MFT mount lenses altogether)

Panasonic's extensive range of CSCs fall into three categories: DSLR style (G6, GH3) compact style (GF6) and rangefinder style (GX7). Panasonic makes widespread use of touchscreen technology, enabling users to select focus points anywhere on the screen, and even fire the camera from the screen. Many of its models offer Wi-fi that lets you control the cameras remotely. Panasonic has the biggest range of its own CSC lenses, and the MFT mount has by far the widest support.

Ricoh Pentax CSCRicoh Pentax

Sensor size: 1/1.7in (Pentax Q series), various (Ricoh GXR)
Current cameras: Pentax Q7, Pentax Q10, Ricoh GXR
Lenses in system: 6 Q system lenses, 5 GXR lens/sensors

The newly amalgamated Ricoh and Pentax have given us three unconventional systems. On the Ricoh GXR the sensors are built into the lenses, with different sensor sizes used with different lenses. The Pentax K-01 was not a success but the tiny Pentax Q system is worth a look. Its use of a compact camera sensor makes it the world's smallest CSC system. The Q7 handles like a tiny DSLR, with full manual control, Raw, and a choice of six lenses for it.

Samsung CSCSamsung

Sensor size: APS-C
Current cameras: Galaxy NX, NX300, NX2000
Lenses in system: 12

Samsung offers two CSC ranges in its NX system: DSLR style with EVFs, and compact style without. All models feature the innovative i-Function button that lets you adjust settings using the lens focus ring, as well as the most advanced Wi-fi connectivity available. The new DSLR-styled Galaxy NX features an Android interface so you can use photo apps such as Instagram, upload direct to social media using 3G, and perform all the non photo tasks you'd do on your phone except make calls.

Sony compact system cameraSony

Sensor size: APS-C
Current cameras: NEX-7, NEX-6, NEX-5R, NEX-3N
Lenses in system: 13 (25 E-mount lenses altogether)

Sony's CSCs all share the same compact camera styling, with only the top two models including a built-in EVF. Based around an APS-C size sensor varying in resolution between 16MP and 24MP, the NEX system prides itself on boasting the world's smallest interchangeable-lens camera bodies with full size APS-C sensors. Unlike Sony's DSLR bodies there's no sensor-based image stabilisation, instead there's optical stabilisation built into selected lenses.