Micro Four Thirds System

The Micro Four Thirds System is a standard created by Olympus and Panasonic for compact digital camera design and development, announced August 5, 2008.cite news | first= | last= | coauthors= | title=Olympus and Panasonic announce Micro Four Thirds | date=2008-08-05 | publisher = DPReview.com | url = http://www.dpreview.com/news/0808/08080501microfourthirds.asp | work =DPReview.com | pages = | accessdate = 2008-08-05 | language = en] The system provides a standard for design of compatible interchangeable lenses and compact cameras by different manufacturers adhering to the system. Micro Four Thirds shares the image sensor size and specification with the established Four Thirds System, designed for digital single-lens reflex cameras. Unlike Four Thirds, Micro Four Thirds does not provide space for a mirror and a pentaprism, which results in smaller dimensions of the camera body (including a smaller lens mount, incompatible with Four Third lens mount). The standard allows use of Four Thirds lenses on Micro Four Thirds camera bodies using a dedicated adapter (Micro Four Thirds lenses cannot be used on Four Thirds bodies whatsoever).

Panasonic has announced a camera and corresponding lenses based on this new system, the Lumix G1 cite news | first= | last= | coauthors= | title=World First: Panasonic Announces µ4/3 camera, Lumix G1 | date=2008-09-12 | publisher = Digitalvesus.com | url = http://www.digitalversus.com/news_id-5952.html | work =Digitalvesus.com | pages = | accessdate = 2008-09-12 | language = en] . Olympus has also announced the development of a camera based on the Micro Four Thirds Systems, though pricing, model name and other specifics are not known at this time. Olympus and Panasonic claim that both these standards are open, however, detailed specifications and the systems' logo remain property of the Four Thirds consortium.

Sensor size and aspect ratio

The image sensor of Four Thirds and Micro Four Thirds is commonly referred to as a "4/3" type" or "4/3 type" sensor (inch-based sizing system is derived from now obsolete video camera tubes). The sensor measures 18×13.5 mm (22.5 mm diagonal), with an imaging area of 17.3×13.0 mm (21.6 mm diagonal). cite web|url= http://www.olympus-europa.com/consumer/dslr_7045.htm |title=No more compromises: The Four Thirds Standard |accessdate=2007-11-09 |work=Olympus Europe ] Its area is 30–40% less than the APS-C sensors used in other manufacturers' DSLRs, yet is around 9 times larger than the 1/2.5" sensors typically used in compact digital cameras.

The Four Thirds system uses a 4:3 image aspect ratio, in common with other compact digital cameras but unlike APS-C or full-frame DSLRs which usually adhere to the 3:2 aspect ratio of the traditional 35 mm format. Thus "The Four Thirds refers to both the size of the imager and the aspect ratio of the sensor". [http://web.archive.org/web/20021205033057/http://www.a-digital-eye.com/Olympus43Q&A.html Knaur] Interview October 01, 2002.]

Lens mount

The Micro Four Thirds lens mount is specified to be a bayonet type with a flange focal distance of circa 20 mm - half as deep as the Four Thirds. The shallow camera body of a Micro Four Thirds standards precludes the use of mirrors, so the cameras will rely on focusing via live view electronic display (either on a large LCD screen or via an electronic viewfinder) or an independent optical viewfinder. A decrease in depth is coupled with a 6 millimeter decrease in flange diameter. Electrically, Micro Four Thirds uses an 11-contact connector between lens and camera (Four Thirds: 9 contacts). Despite this difference, Olympus claims full compatibility of existing Four Thirds lenses with Micro Four Thirds bodies, using a dedicated adapter.

The shallow but wide lens mount will also allow coupling Micro Four Thirds bodies, via aftermarket adapters, to existing stock of manual focus lenses, including Leica M and Olympus Pen F ones. Critics, however, suggest that the contrast-detection autofocus inherent in compact cameras and requiring powerful focusing motors may not operate properly on (at least some of) the existing Four Thirds lenses designed for phase-detection autofocus.Micro Four Thirds System. By Dave Etchells, The Imaging Resource [http://www.imaging-resource.com/NEWS/1217960634.html] ]

Advantages, disadvantages and other factors

"For comparison of the original Four Thirds with competing DSLR system see Four Thirds System#Advantages, disadvantages and other factors"

Compared to existing compact cameras (equipped with non-interchangeable lenses and smaller image sensors), Micro Four Thirds aims to offer a compact solution with interchangeable lenses and a larger sensor (same as in Four Thirds DSLRs). The system can benefit a compact camera user through:
* Choice of fast yet compact lenses optimal for the task; since the system (unlike Four Thirds) does not postulate telecentricity as a key design rule, Micro Four Thirds lenses of the same focal length can be made significantly smaller and lighter than in Four Thirds system.
* Lesser digital image noise due to larger pixel area, extending the usable ISO speed and enabling cleaner shots in low-light conditions without using electronic flash
* Reasonable depth of field (same as in Four Thirds DSLRs but more than in full frame cameras)
* Convenient framing via an electronic viewfinder

Micro Four Thirds system companies

Up to now, only Olympus and Panasonic have a commitment to Micro Four Thirds system. The original Four Thirds consortium also includes (in alphabetical order):
Fuji, Kodak, Leica, Olympus, Panasonic, Sanyo and Sigma.

Micro Four Thirds system cameras

The Panasonic Lumix DMC-G1 is the first Micro Four Thirds System camera to be announced. The camera has an electronic viewfinder (EVF) as well as a live-view LCD. [ cite web|url=http://www.dpreview.com/news/0809/08091202panasonic_DMC_G1.asp|title=Panasonic Lumix G1 previewed]

Olympus has announced a Micro Four Thirds System camera as well, but no specifics are available at this time, with the exception of a mock up designed by Olympus to demonstrate how the camera will look.

References

See also

*Lenses for SLR and DSLR cameras
*Lens mount
*List of lens mounts

External references

* [http://www.flickr.com/groups/olympus-e500/ URO | Usuarios Réflex Olympus] Flickr group of Olympus DSRL Spanish Users
* [http://www.four-thirds.org/en/microft/ The Micro Four Thirds Standard] official pages.
* [http://fourthirdsphoto.com Fourthirdsphoto.com] Site for Four Thirds System users.
* [http://www.fourthirds-user.com Four Thirds User] Site for Four Thirds System users.
* [http://www.flickr.com/groups/4-3rd/ Flickr Group For Four Thirds] Flickr Group for Four Thirds.
* [http://www.ftna.es Foro hispano del formato Cuatro Tercios] Forum in Spanish about the Four Thirds system.