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The FourThirds Lens System

By Allan Weitz

Just as you hope the guy who fixes your car has more than a flathead screwdriver and ball-peen hammer in his toolbox, the choice of lenses available for your camera system greatly defines your limits of creativity. Regardless of how many megapixels your camera's sensor contains or how many frames-per-second it can bang out, if you lack the option to shoot with an ultra-wide, ultra-long, or ultra-fast lens when the need arises, you might as well leave the camera bag home and just buy picture postcards along the way.

Size and weight aside, perhaps the greatest selling point of the 4/3 and newer Micro-4/3 camera systems is the wide range of focal-lengths available for them. With a choice of focal lengths ranging from 7mm (114° AOV) through 800mm (1.5° AOV), the 4/3-format system actually offers a wider range of optical choices than any 35mm lens system currently in production. You also have the option of adapting lenses from other manufacturers onto 4/3 and Micro-4/3 camera bodies using adapters manufactured by Olympus, Panasonic, and Novoflex. (To learn how to mount a Canon 1200/5.6L EF super-telephoto on a Micro-4/3 camera click here.)

Currently, 4/3 and Micro-4/3 format lenses are manufactured by Olympus, Panasonic, Sigma, and Leica (through it's affiliation with Panasonic). Regardless of manufacturer, each of these lenses works equally well with any 4/3-format camera system, and your choices are surprisingly varied, whether you seek zooms, macros, or fast fixed focal-length prime lenses.

Keep in mind 4/3 and Micro-4/3 sensors are half the size of ‘full-frame' (24 x 36mm) imaging sensors, and as such the equivalent focal length of a 4/3-format lens is twice-up from its full-frame equivalent. This means a 25mm lens has the angle-of-view of a 50mm normal lens (about 46°) and a 50mm lens now has the angle-of-view of a 100mm portrait lens (about 20°) on a full-frame DSLR.

Note- Standard 4/3-format lenses can be used on Micro-4/3 format cameras, but not visa-versa.

Ultra-Wide Zooms

Olympus – With a wide-end angle-of-view of 114°, the Olympus 7-14mm/f4 Zuiko Digital ED makes easy work of creating dramatic, depth-defying imagery. With a focal range that covers ultra-wide through wide (14 – 28mm equivalent), this unique zoom serves as an all-in-one optic for any and all wide-angle needs. This lens contains an impressive 18 elements in 12 groups, contains 2 aspherical and 2 extra-low dispersion (ED) lens elements, and has a minimum focus of 9.8" for dramatic close-ups.

Slightly less wide, almost twice as long (focal length-wise), and a full-stop faster is the Olympus 11-22mm/f2.8-3.5 Zuiko Digital lens (22-44mm equivalent), which contains 12 elements in 10 groups (including 2 aspherical lens elements) and a minimum-focus of 11". Despite its faster wide aperture, the Olympus 11-22mm is over 10 ounces lighter than the wider Olympus 7-14/4. If speed and weight matters more than angle-of-view, this lens is well worth considering.

The Olympus 9-18mm f/4-5.6 ED Zuiko zoom lens (18-36mm equivalent) features dual aspheric lens elements and a close-focusing distance of 9.8", and is the least expensive and most compact wide zoom in the Olympus line-up.

Sigma – With a field-of-view comparable to a full-frame 20-40mm lens, the Sigma 10-20mm/f4-5.6 EX DC HSM contains 14 elements in 10 groups including 3 Special Low Dispersion (SLD) elements as well as 3 aspheric elements whose job it is to maintain a high level of image quality throughout the zoom range. Minimum focus for the Sigma 10-20 zoom is 9.4".

Wide Zooms

Olympus, Panasonic, and Sigma each offer a selection of optics in this class that go from wide to normal, wide to semi-long, and wide to very long, and often with a choice of maximum apertures.

Olympus- The widest of this group is the Olympus 12-60mm/f2.8-4 Zuiko Digital ED, which with an AOV equal to a 24-120mm lens and a maximum aperture of f/2.8 (in the 24mm position) makes for a good all-in-one daytripping lens. This zoom contains 14 elements in 10 groups and focuses down to about 9.8".

For those seeking a wide zoom suitable for shooting under low-light conditions or situations that call for shallow depth-of-field, have a look-see at the Olympus 14-35mm/f2 Zuiko Digital ED, a hefty zoom that features a fixed f/2 maximum aperture throughout the zoom range and 18 elements in 10 groups including dual ED elements and one aspheric lens element.

Slightly slower (and lighter) is the Zuiko Digital 14-54mm/2.8-3.5 II (about 74°-20°AOV), which contains an Olympus High-Speed Imager AF, dust and splash-proof construction, 3 aspherical elements, and a minimum focusing distance of 8.66" for half life-size (1:2) close-ups.

If size and weight is an issue, Olympus has a 14-42mm/f3.5-5.6 Zuiko Digital Lens, which along with its compact dimensions, features ED glass, dual aspherical lens elements, measures a mere 2.4" in length, and weighs in at a mere 6.7 ounces.

Panasonic- If you're looking for a 4/3-format zoom in the wide to portrait-telephoto range Panasonic offers a choice of zooms in the 14-50mm range to fill your needs. The Leica-designed Leica D Vario-Elmarit 14-50mm/2.8-3.5 ASPH MEGA O.I.S is the faster of the 2 lenses with a maximum aperture of f2.8 (down to f3.5 at the long end of the zoom range), dual aspherical lens elements, and a built-in optical image stabilizing system to smooth out the bumps under low-lighting conditions. (Yeah, we know it's redundant, but it's our job to inform you of the facts)

A slightly slower (and about $250 less-costly) option is Panasonic's 14-50mm/f3.8-5.6 Vario-Elmar ASPH MEGA O.I.S, which contains 2 aspherical elements, 2 ED elements for reduced chromatic aberrations, a minimum focus of 11.4" and a similar Leica bloodline.

And if you're looking for a longer stretch of millimeters that takes you from wide angle to long telephoto check out Panasonic's 14-150mm/3.5-5.6 Leica D Vario-Elmar ASPH MEGA O.I.S, which along with a 10.7x magnification range (about 74°-15°) and that neat red Leica badge, contains Extra Silent Motor technology (XSM), 4 aspherical lens elements and 1 ED glass element for minimizing chromatic aberrations.

Sigma- Sigma's midrange contribution is an 18-50mm/f2.8 EX DC Macro which enables you to focus down to 1/3 life-size complimented by a wide f/2.8 aperture that remains f/2.8 throughout its zoom range.

Mid-to-Long Range Zooms

Olympus- This is where things start getting busy. Starting with Olympus, we have a cost-conscious 40-150mm/f4-5.6 Zuiko Digital ED, which takes you from short telephoto (about 28°, or 80mm equivalent) to long telephoto (about 8.2°, or 300mm equivalent). Other features include an ED glass element and a close-focusing distance of 35.4". Taking things a bit further (and faster), Olympus offers a 50-200mm/f/2.8-3.5 Zuiko Digital SWD ED lens that contains 3 ED elements for maintaining aberration-free images and a zoom range that goes to an AOV of 6° (400mm equivalent).

Olympus 40-150mm f/4-5.6 Zuiko ED Zoom Lens for Olympus Digital Cameras (Four Thirds System)Sigma 18-50mm f/2.8 EX DC Macro Lens for Olympus (4/3 System)

The Olympus 70-300mm/f4-5.6 Zuiko Digital ED (about 17°-4.2° AOV) offers a longer zoom range, a moderate aperture range, 3 Extra-low Dispersion elements, and an easy-to-tote-around-all-day weight of 615 grams. It can also focus down to a near-macro magnification of 0.5x. Slightly narrower in range but noticeably faster throughout its focal range is the Olympus 90-250mm/f2.8 Zuiko Digital ED (about 13.7°-5° AOV), which maintains a fast f/2.8 maximum regardless of how far you zoom into your subject.


Packing 4 Special Low Dispersion (SLD) elements out of a total 20 elements in 16 groups, the Sigma APO 50-500mm/f4-6.3 EX DG HSM is a 10x zoom with an AOV range of about 20° - 2.7° (100-1000mm equivalent), which makes it an ideal lens for safaris, sports photography, and other photo-ops where getting steamrolled by a quarterback or eaten by a lion are possibilities. A removable tripod collar makes it easy to shoot from a tripod as well as well-braced hand-held shooting.

A bit more modest is the Sigma 55-200mm/4-5.6 DC, which aside from its affordable price is both compact and lightweight. A faster alternative, and one that focuses down to 1:3 life-size is the Sigma 70-200mm/f2.8 II EX DG Macro HSM, which maintains a constant f2.8 maximum aperture throughout its focal range. With an AOV ranging from about 8° to 16°, this hefty zoom contains 18 elements in 15 groups including 2 SLD (Special Low Dispersion) and 3 ELD (Extra-low Dispersion) elements for maximizing image quality throughout the entire zoom range. This lens also contains Hyper Sonic Motors (HSM) for quicker and quieter AF response times and on-demand manual over-ride.

And for those who really like to snag distant vistas (and have $9,999.00 to burn) , definitely have a look at Sigma's 300-800mm/f5.6 EX DG HSM, which with a dizzying AOV range of about 4.2° to 1.5°, is the equivalent to a 600-1600mm/5.6 zoom on a full-frame DSLR, which is as long as it gets among telephoto zooms in any format. The Sigma 300-800/5.6 comes with a tripod collar, and we strongly urge you to make use of it whenever possible.

Fixed Prime Lenses

The choices among fixed focal-length prime lenses are equally impressive for 4/3 system users. Though there's a wide gap in fixed focal length wide-angle lenses (they go from fisheye to a near-normal 24mm), what is available is a nice choice of fast optics in a wide range of focal lengths. As for wide-angle lenses, you'll have to be happy with the wide zooms mentioned at the beginning of this text.

Olympus- For those of you who can never squeeze enough into each frame Olympus offers the 8mm/f3.5 Fisheye ED Zuiko Digital Lens, which fills your frame with a 180° view of everything before you. Consisting of 10 elements in 6 groups (including ED elements) and with a minimum focus of 5.3", the Zuiko ED Fisheye features dust and splash-proof construction.

Following the fisheye, Olympus offers a 25mm/f2.8 Zuiko Digital pancake-style normal lens (46° AOV) that makes for a compact companion to any 4/3-system camera. Using a simple (but sharp) optical design, the 25/2.8 Zuiko contains 5 elements in 4 groups, focuses down to a near-macro 7.87".

The Olympus 150mm/f2 Zuiko ED is a true speed queen. With an AOV of 8.2° (300mm equivalent) and a maximum aperture of f/2, the 150/2 Zuiko ED makes for an ideal sports optic. Along with 2 aspheric elements and a close-focusing distance of 55", the 150/2 Zuiko ED features a built-in tripod collar, though it easily lends itself to hand-held shooting.

Need something longer? Check out the Olympus 300mm/f2.8 Zuiko Digital ED, which boasts an AOV of a mere 4.2° (600mm equivalent), 3 Super ED elements (13 elements in 11 groups total), and a tripod collar, which despite the lens' fast maximum aperture should be used whenever possible unless you're real steady and caffeine-free.

Sigma- Sigma's 30mm/f1.4 EX DC HSM is a slightly long normal lens (60mm equivalent) with the widest aperture among 4/3-system lenses. The Sigma 30/1.4 utilizes a combination of SLD and ELD elements (7 elements in 7 groups total) and HSM drives for fast focusing, MF over-ride, and low-aberration imaging. The 30/1.4 EX DC HSM focuses down to 15.75".

For portraits and short telephoto needs Sigma's 50mm/f1.4 EX DG HSM is well worth consideration. Consisting of 8 elements in 9 groups including 2 Super ED and 1 aspheric element, the 50/1.4 EX DG HSM is designed to deliver sharp imaging wide open as well as stopped down a few clicks.

Macro Lenses

Macro photography is another area that is well addressed by Olympus and Sigma in an optical range unmatched by any other imaging format.

Olympus- The shortest of the lot is the Olympus 35mm/f3.5 Zuiko Digital Macro, which contains 6 elements in 6 groups and a minimum focus of 5.75" for life size imaging. With an AOV of about 17°, the Olympus 35/3.5 macro has a 35mm equivalent of 70mm on a 35mm camera.

Slightly longer with an AOV of 20° (100mm equivalent) is the Olympus 50mm/f2 Zuiko Digital ED, which contains 11 elements in 10 groups (including 1 Super ED element and a floating element for sharp imaging throughout it's focusing range, and a minimum focus of 12.20" for a half life-size image capture.

Sigma- For longer focal length macro shooting you can turn to the Sigma 105mm/f2.8 EX DG Macro, which with an AOV of about 12° (210mm equivalent) can capture life-size images from 12.2" from your subject. The Sigma 105/2.8 EX DG Macro contains 11 elements in 10 groups.

The longest of the bunch is Sigma's 150mm/f2.8 APO Macro EX DG HSM, which sports an AOV of 8.2° (30mm equivalent) for life-size imaging from a distance of 14.96" from the subject. Containing 16 elements in 12 groups including 2 Super ED elements, the Sigma 150/2.8 APO Macro comes with a detachable tripod collar, which you should seriously consider using when shooting at close range to your subject.

Teleconverters and Extension Tubes

Olympus offers a choice of teleconverters for further extending the versatility of 4/3 optics. The Olympus 1.4x Teleconverter EC-14 extends the focal length of 4/3 lenses by a factor of 0.4 (and with a 1-stop loss of effective light), while the Olympus 2x Teleconverter EC-20 doubles the focal length of 4/3 lenses with a 2-stop loss of effective light.

Olympus EX-25 Extension Tube Olympus EC-20 2.0X Teleconverter

For extending the close-focusing abilities of 4/3 lenses, the Olympus Extension Tube EX-25 enables you to focus 4/3 lenses closer than their specified closest focusing distance. Depending on w hich lens you use it with, there is a variable loss of effective light, but it's a handy tool for pushing the limits of creativity when shooting close-up imagery.

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