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The Four Thirds System is a standard created by Olympus and Kodak for digital SLR camera design and development. (Four Thirds is a registered trademark of Olympus Optical Co., Ltd.) Image File history File links 4_3logo. ... Image File history File links 4_3logo. ... This article refers to a Japanese camera maker. ... Eastman Kodak Company (NYSE: EK) is a large multinational public company producing photographic equipment. ... 10 MP Nikon D200 and a Nikon film scanner The Canon EOS 350D The Canon PowerShot A95 Digital photography, as opposed to film photography, uses electronic devices to record and capture the image as binary data. ... The single-lens reflex (SLR) is a type of camera that uses a movable mirror placed between the lens and the film to project the image seen through the lens to a matte focusing screen. ... Large format camera lens. ... All Saints Chapel in the Cathedral Basilica of St. ... Technology development is the process of research and development of technology. ...

The system provides a standard which, with digital cameras and lenses available from multiple manufacturers, allows for the interchange of lenses and bodies from different manufacturers. U.S. Patent 6,910,814  seems to cover the standard. Four Thirds is not an open standard, however, as it does not meet the "allowing anyone to use" criterion commonly accepted as the definition of an open standard.^{[citation needed]} Standardization, in the context related to technologies and industries, is the process of establishing a technical standard among competing entities in a market, where this will bring benefits without hurting competition. ... This article or section does not cite any references or sources. ... Photographic lens One of Canons most popular wide angle lenses - 17-40 f/4 L The zoom lens of the Canon Elph A photographic lens (or more correctly, objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images... Manufacturing is the transformation of raw materials into finished goods for sale, or intermediate processes involving the production or finishing of semi-manufactures. ... This article or section cites very few or no references or sources. ...

Unlike older SLR systems, Four Thirds has been designed from the ground up to be entirely digital. Lens design has been tailored to the requirements of digital sensors, most notably through telecentric designs. The advantages of the system include more compact telephoto lenses (a Four Thirds lens with a 300 mm focal length would cover about the same angle as a 600 mm focal length lens for the 35 mm film standard) and more even delivery of light to different parts of the sensor. This gives it a crop factor of exactly 2. A telecentric lens is a compound lens with an unusual property concerning its geometry of image-forming rays. ... The focal point F and focal length f of a positive (convex) lens, a negative (concave) lens, a concave mirror, and a convex mirror. ... 135 Film Size, Kodak Tri-X 400 speed 135 (ISO 1007) is a film format for still photography. ... This term emanates from DSLR technology. ...

Sensor size and aspect ratio

The name of the system comes from the size type of the image sensor used in the cameras. The image sensor is commonly referred to as a 4/3 type or 4/3 type sensor. The nominal size of four-thirds of an inch is based on a method of calculation that was introduced when vacuum image-sensing tubes were first invented. The imaging area of the sensor (17.3 mm x 13 mm) is the same as the imaging area of a vacuum image-sensing tube of 4/3" diameter.

The size of the sensor is 18 mm × 13.5 mm (22.5 mm diagonal), with an imaging area of 17.3 mm × 13.0 mm (21.6 mm diagonal). This is smaller than most other digital SLR sensors and larger than the sensors used in compact digital cameras (see image sensor format). In digital photography, the image sensor format is the shape and size of the image sensor. ...

The Four Thirds system uses a 4:3 image aspect ratio, which is common in many other digital cameras. This is in contrast to the traditional 35 mm format with an aspect ratio of 3:2. The Four Thirds standard specifies the aspect ratio in addition to the size of the imaging circle. Claim 1 of US patent 6,910,814, mentioned earlier in this article, is quite specific: "…said camera body having an image pickup device having an imaging range with an aspect ratio of 4:3 on an imaging surface within the image circle…" The aspect ratio of an image is its displayed width divided by its height (usually expressed as x:y or x×y, with the joining colon or multiplication symbol articulated as the preposition by or sometimes to). Currently, the most popular standard ratios are the anamorphic (2. ...

A major reason for choosing 4:3 for the sensor proportions is that it has historically been the standard for television and became a dominant aspect ratio for computer monitors, as found in the VGA, SVGA, XGA, SXGA+, UXGA and QXGA standards. Video Graphics Array (VGA) is a computer display standard first marketed in 1987 by IBM. VGA belongs to a family of earlier IBM video standards and largely remains backward compatible with them. ... Super Video Graphics Array, almost always abbreviated to Super VGA or just SVGA is a broad term that covers a wide range of computer display standards. ... XGA, the eXtended Graphics Array, is an IBM display standard introduced in 1990. ... SXGA+ stands for Super eXtended Graphics Array and is a computer display standard. ... UXGA is an abbreviation for Ultra eXtended Graphics Accelerator referring to a standard monitor resolution of 1600 × 1200 pixels, which is exactly quadruple the default resolution of SVGA (800 × 600). ... The QXGA display standard and its derivatives are relatively new (as of 2005) resolution standards in display technology. ...

It is an advantage to know the aspect ratio during the design of a lens. Indeed, many lenses designed by Olympus for the Four Thirds system contain internal rectangular baffles or permanently mounted "petal" lens hoods that optimise the lenses operation for the 4:3 aspect ratio.

Mechanical considerations

The Four Thirds lens mount is specified to be a bayonet type with a flange focal distance of 38.67mm. A Leica R series teleconverter, with the female side of the Leica R bayonet mount. ... The flange focal distance (also known as the flange-to-film distance, flange focal depth, or register, depending on the usage and source) of a lens mount for an interchangeable lens camera system is one of its most fundamental attributes. ...

Advantages, disadvantages and other factors

Advantages

• The smaller sensor size makes possible smaller and lighter camera bodies and lenses. In particular, the potential exists for very fast lenses and very high quality lenses at lower costs. Currently this is evident to some extent in the Olympus E-400 and E-410 bodies and their kit lenses, and in longer telephoto lenses.

• Telecentric optical path means that light hitting the sensor is traveling perpendicular to the sensor, resulting in brighter corners, and most importantly improved off center resolution, particularly on wide angle lenses.

• Because the flange focal distance is significantly shorter than most competing mounts (such as Canon FD, Canon EF, Nikon F and Pentax K), lenses for many other SLR types can be fitted to Four Thirds cameras with simple mechanical adapter rings. (Such mechanical adapter rings typically require manual setting of focus and aperture.)

Disadvantages

• Smaller sensors are generally more prone to noise. This typically becomes most pronounced at high ISO exposures, meaning that picture quality may suffer in low light situations where the ISO has to be increased to 400 or above.

• There are not as many lenses available as for some of the competing DSLR systems. (As mentioned above, lenses for competing systems can usually be mounted, but with the loss of auto-focus and the need for manual setting of aperture. Note also that this is not an intrinsic disadvantage of the Four Thirds System, and the situation could change at some time in the future.)

Image noise is unwanted and manifested in the pixels of an image. ... Film speed is the measure of a photographic films sensitivity to light. ...

Other factors

The following two factors can be considered to be advantages under certain circumstances and disadvantages under other circumstances.

• The smaller sensor means that the depth of field is greater than for cameras with a larger sensor. See depth of field: DOF vs. format size for a discussion of this phenomenon. Compared to a 35mm or full frame camera the depth of field is approx. twice as great. Compared to most other DSLR cameras that use APS-C size sensors the depth of field for a Four Thirds camera is approx. 25% greater.

Whether this greater depth of field is an advantage or disadvantage depends on the desired effect. For taking portraits or other pictures where the subject is to be isolated from the background (by blurring the background) it is a disadvantage. For landscape, telephoto and macro photography, and most point-and-shoot photography, it is an advantage.

• The aspect ratio of pictures taken with a Four Thirds camera is 4:3, while all other DSLR cameras and 35mm film cameras take pictures with an aspect ratio of 3:2. (All compact digital cameras take pictures with a 4:3 aspect ratio.)

For traditional print and frame sizes that have an aspect ratio of 3:2 (6×4", 9×6", 12×8") this is a disadvantage for Four Thirds cameras as photographs will have to be cropped or printed with borders to fit these sizes. The same applies if the picture is to be used for a wide-screen application.

Some other traditional print sizes (5×7", 8×10", 11×14") are closer to a 4:3 aspect ratio than they are the 3:2 aspect ratio, meaning the photographer does not need to crop as much or have large matting to meet these sizes. The same applies for pictures to be used on standard PC screens and non-HDTV television screens.

In optics, particularly film and photography, the depth of field (DOF) is the distance in front of and beyond the subject that appears to be in focus. ... In optics, particularly film and photography, the depth of field (DOF) is the distance in front of and beyond the subject that appears to be in focus. ... A full-frame digital SLR is a digital single-lens reflex camera fitted with an image sensor that is the same size as a 35 mm negative. ... Advanced Photo System type-C (APC-C) is a type of sensor used in digital Single Lens Reflex cameras, also called dSLRs. ...

Four Thirds system companies

As of the 2006 Photo Marketing Association Annual Convention and Trade Show, the Four Thirds consortium consists the following companies (in alphabetical order): Year 2006 (MMVI) was a common year starting on Sunday (link displays full 2006 calendar) of the Gregorian calendar. ... The Photo Marketing Association International (or PMA) Annual Convention and Trade Show is an annual imaging technology trade show conducted by PMA (About PMA, n. ... For other uses, see Alphabet (disambiguation). ... Alphabetical redirects here. ...

• Fuji
• Kodak
• Leica
• Olympus
• Panasonic
• Sanyo
• Sigma

This should not be interpreted as a commitment to end user products by each company. Up to now, only Leica, Olympus and Panasonic have bodies, and Leica, Olympus and Sigma have lenses in the market. Kodak, for example, has sensors to sell to body makers. Fujifilm Holdings Corporation, or Fujifilm, is a Japanese company known for its photographic film and cameras. ... Eastman Kodak Company (NYSE: EK) is an American multinational public company. ... Leica is the name of several cameras produced by a German company of the same name. ... This article refers to a Japanese camera maker. ... Logo for the Panasonic brand Matsushita Electric Industrial Co. ... Sanyo Electric Co. ... Sigma Corporation ) is a Japanese company manufacturing cameras, lenses, flashes and other photographic accessories. ...

Four Thirds System cameras

• Olympus E-1 (November 2003)
• Olympus E-300 (December 2004)
• Olympus E-500 (September 2005)
• Olympus E-330 (January 2006)
• Panasonic Lumix DMC-L1 (February 2006)
• Leica Digilux 3 (September 2006)
• Olympus E-400 (September 2006)
• Olympus E-410 (April 2007)
• Olympus E-510 (June 2007)
• Panasonic Lumix DMC-L10 (October 2007)
• Olympus E-3 (still not official, shipping expected November 2007)

The Olympus E-1 introduced in 2003 was the first DSLR designed from the ground up for digital photography. ... The Olympus E-300 (Olympus Evolt E-300 in North America) was an 8 megapixel digital SLR manufactured by Olympus of Japan and based on the Four Thirds System. ... The Olympus E-500 (Olympus EVOLT E-500 in North America) is an 8 megapixel SLR digital camera manufactured by Olympus of Japan and based on the Four Thirds System. ... Image:Olympus E-330. ... The Lumix DMC-L1 is a Panasonic Digital single-lens reflex camera launched the 28 February 2006, using the Four Thirds System lens mount standard. ... Image:Leica Digilux 3. ... The E-400 is a digital single-lens reflex camera launched by Olympus on the 14th of September 2006, using the Four Thirds System lens mount standard. ... The Olympus E-410 (or Olympus EVOLT E-410 in North America) is a 10 megapixel digital single lens reflex (dSLR) camera intended to compete in the entry level market. ... The Olympus E-510 (or Olympus EVOLT E-510 in North America) is a 10 megapixel digital single lens reflex (dSLR) camera oriented to the prosumer or hobbyist market. ... The Lumix DMC-L10 is a Panasonic Digital single-lens reflex camera which uses the Four Thirds System lens mount standard, and was announced on August 2007. ... The Olympus E-1 successor, originally codenamed Olympus E-P1, is now known as E-3. ...

Four Thirds System lenses

There are currently almost three dozen lenses for the Four Thirds System standard.^[1]

• Olympus has announced a total of 20 lenses for the Four Thirds System, including a couple not yet released and a couple superseded by newer models. Focal lengths range from 7 to 300mm, and include macros.
• Sigma has adapted 12 lenses for the Four Thirds System, ranging from 18 to 800mm.
• Leica has made two lenses for the Four Thirds System, a standard zoom with optical image stabilization and a fast 25mm normal lens, and has announced two new lenses, including a 14-150mm super-zoom with optical image stabilization.

This article refers to a Japanese camera maker. ... Sigma Corporation ) is a Japanese company manufacturing cameras, lenses, flashes and other photographic accessories. ... Leica is the name of several cameras produced by a German company of the same name. ... Image stabilization is a family of techniques to increase the stability of an image. ...

References

1. ^ Wrotniak lens list.

See also

• Lens mount
• List of lens mounts

A Leica R series teleconverter, with the female side of the Leica R bayonet mount. ... This list of lens mounts is ordered by flange focal distance, from shortest to longest. ...

External links

• Official Four Thirds System site.
• Four Thirds US patent 6,910,814; PDF version (1.7 MiB)
• Andrzej Wrotniak's pages about the Four Thirds System include a complete lens list.

NEW *Four Thirds User site.