see also:

• Micro Four Thirds system
• Sony NEX camera system
• Samsung NX mirrorless camera system
• Fujifilm X mirrorless system
• Nikon 1 mirrorless camera system
• legacy lenses for mirrorless cameras
• lens mount cross-compatibility table
• dpreview.com's primer on mirrorless camera systems - gives you more details to help you understand why mirrorless cameras are so popular
• why Micro Four Thirds is the best choice in mirrorless cameras in 2012
• MirrorlessDB.com's listing of lenses for each of the mirrorless camera system mounts

Mirror-less interchangeable lens digital cameras are the new force in digital photography providing novel designs, more silent and compact camera kits designed for live view and HD video while providing dSLR level still image quality.

The clear leader in this genre is the 2x crop sensor Micro Four Thirds system pioneered by Panasonic and Olympus which offers the widest range of legacy lens compatibility of any camera system, while still having a range of optimised AF lenses designed for that sensor size including the wonderful Panasonic 20mm f/1.7 pancake, the compact, high quality 7-14mm ultra-wide lens, 12mm f/2.0 wide angle, 45mm f/1.8 portrait, 75mm f/1.8 short telephoto prime lenses and the unique Panasonic 14-140mm HD video optimised lens. The differentiating benefits of Micro Four Thirds include:

• ability to use almost any legacy lens ever made including Leica M, and with many, even convert them into tilt-shift lenses via an adapter for use in either still images or HD video, and when used on Olympus cameras, they will also be image stabilised and you have the option of very nice fun art filters – just incredibly awesome creative fun – this is what photography should be all about for most of us!
• perfect compromise on sensor size for image quality and lens size and weight
• very nice, and expanding range of dedicated AF lenses from consumer grade (Olympus 17mm f/2.8 pancake) to mid-grade (Panasonic 14-140mm HD lens, Panasonic 20mm f/1.7 pancake, Olympus 45mm f/1.8 portrait lens) to semi-professional grade (eg. Panasonic 7-14mm, 12mm f/2.0, 25mm f/1.4, 45mm f/2.8 OIS macro, etc)
• ability to use the wonderful Four Thirds lenses such as Leica-D 25mm f/1.4 and Olympus 50mm f/2.0 macro although AF may be slow or not possible depending on the camera and the lens
• image stabilised bodies – the Olympus ones
• flip out and swivel LCD screens with built-in EVF – the Panasonic Gx and GH-x series
• tilt out LCD screen in a weatherproofed, high end body with built-in image stabilisation and EVF - the Olympus OM-D
• the best electronic viewfinders available – the Panasonic GH2/GH3/G3/G5, the Olympus E-M5/E-P3/E-PL3 (although now joined by the Sony NEX7/6)
• the fastest AF for stationary subjects - the current Olympus models

Ricoh offers an interesting design alternative with its GXR system in which each lens has its own sensor permanently attached to it and designed to match the expected usage of that lens. This may suit a few people but its main downside is that as sensor technology becomes out of date, you not only have to change the sensor but the lens system as well, which is likely to mean a more expensive longer term cost - assuming Ricoh does continue development.

Then there is the expected range of APS-C sized sensor camera systems which I feel defeats the purpose behind this genre – that of enabling smaller lenses with versatility of using any legacy lens even with tilt-shift adapters such as is possible on the Micro Four Thirds system:

• Sony NEX camera system
• Samsung NX mirrorless camera system
• Fujifilm X mirrorless system
• Canon EOS-M EF-M compact mirrorless system
• Sigma Foveon
• Hoya/Pentax announced the K-01 in Feb 2012
  • surprisingly they kept the same flange distance as their dSLRs which seems to give it the worst of all worlds - thick body of a dSLR but without an optical viewfinder nor a fast AF system, nor lenses optimised for contrast detect AF, and unlike most of the other mirrorless cameras, unable to take rangefinder legacy lenses.
  • but at least it has image stabilisation built in and peaking to assist manual focus and it looks stylish.

• these cameras have much smaller sensors than the above and thus allow smaller lenses and cameras but will never have the image quality or ability to blur the background as well as those cameras with larger sensors
• they are designed for portability but the tiny sensor size means very limited ability to grow with these systems as a photographer
• many may be just as well off using their iPhone
• Nikon 1 mirrorless camera system
  • Nikon has gone the small sensor route with a 2.7x crop sensor half the size of the Micro Four Thirds sensor, which makes good sense for those wanting even smaller systems if Nikon can come out with nice small fast primes and zoom lenses, but the 2.7x crop factor will further impact usability of legacy lenses, and image quality – both in terms of sensor sensitivity, and in terms of ability to blur the background.
• Pentax Q mirrorless camera system
  • the Pentax Q system uses a tiny 1/2.3” sensor which is 1/8th the size of the sensor used in Micro Four Thirds cameras and 1/13th the size of the the APS-C format sensor giving a 5.5x crop factor

• Not only does Micro Four Thirds have a much wider range of options in camera bodies but their lens range is awesome!
• Micro Four Thirds clearly as the best range of lenses, and importantly, note the number of wide aperture lenses and the more compact size and lower weight of many of the lenses compared with APS-C sized lenses required for Sony and Samsung.
• The 2x crop factor of the Micro Four Thirds also means you get more telephoto reach, you can have the reach of a compact 600mm telephoto zoom - twice as much as what is available for Sony or Samsung.
• NOTE that ALL lenses on Olympus bodies become image stabilised (up to 5EV in 5 axes on the OM-D camera)

Clearly the BEST mirrorless camera in terms of versatility, functionality for the enthusiast photographer and compact AF lens availability is the Olympus OM-D E-M5 camera.

If you want the best videography the Panasonic GH-3 is the way to go.

Perhaps the best reason to buy Micro Four Thirds over the competition are the following compact Micro Four Thirds lenses combined with 5EV IS of the OM-D, which are all under $1000 each (some under $400):

• Olympus 12mm f/2.0
• Olympus 17mm f/1.8 (rumoured for 2013?)
• Panasonic 20mm f/1.7 pancake - all party girls should have this lens!!!
• Panasonic 25mm f/1.4
• Olympus 45mm f/1.8 portrait
• Olympus 60mm f/2.8 macro
• Olympus 75mm f/1.8
• Olympus 75-300mm lens for sharp 600mm super telephoto in an easily hand held lens.
• and if the above are not enough you can always play with the Panasonic 7-14mm lens or the fisheye lens for ultra wide creativity, or the 3D lens for stereo video.