One of the key selling points of Micro Four Thirds (MFT) camera systems has to do with weight and size, and even though most MFT camera bodies are barely (if at all) smaller or lighter than their APS-C and full-frame counterparts, lenses designed for MFT-format cameras are another story.
To illustrate our point, we chose an Olympus OM-D E-M1 Mk II camera, along with five fast Olympus Micro Four Third prime lenses (17mm f/1.2, 25mm f/1.8, 45mm f/1.2, 45mm f/1.8, and 75mm f/1.8) and put them through their paces.
Olympus OM-D E-M1 Mk II
The list of features packed into the Olympus OM-D E-M1 Mk II is long and thorough enough to satisfy the needs of the pickiest pros. The heart of the OM-D E-M1 Mk II is a 20.4MP MFT Live MOS sensor that, together with a TruePic VIII Dual Quad Core processor, enables you to capture up to 60 20Mp RAW files per second in S-AF Mode, 18 fps in C-AF Tracking Mode, or full-resolution image files at up to 15 fps in S-AF Mode when using the camera’s high-speed mechanical shutter.
For composing and reviewing stills and video, the Olympus OM-D E-M1 Mk II offers a choice of a high-res (2.36m-dot) EVF and 1.04m-dot Vari-Angle touchscreen. The camera’s Dual F.A.S.T 121-point AF system performs soundly, and there’s a 5-axis image-stabilization system designed to reduce the effects of camera shake by about 6.5 stops.
For the times you can’t afford to miss the moment, the OM-D E-M1 Mk II has a Pro Capture Mode that triggers the camera’s silent electronic shutter to begin capturing consecutive JPEG/RAW files when the shutter button is pressed halfway. When the button is fully pressed, the camera takes the picture and records it, along with the preceding 35 frames.
Need maximum resolving power? The camera’s 50-Megapixel High-Res Shot Mode captures 8 frames while shifting the sensor slightly on the vertical and horizontal planes. All 8 images are then combined into a single, finely detailed 50Mp image file. Other image quality-enhancing features include Focus Bracketing and Stacking.
If video is a priority for you, the Olympus OM-D E-M1 Mk II captures Cinema 4K video at a max bit rate of 237 Mbps at 24P, or you can shoot 4K video at a choice of 30P, 25P, or 24P.
Other features found on the Olympus OM-D E-M1 Mk II include a weatherproof magnesium-alloy body and dual SD memory card slots. The total weight of the camera including the battery is a mere 1.26 lb.
Size and Weight
MFT lenses tend to be about half the size and a third the weight of their equivalent APS-C and full-frame counterparts. For example, the Olympus M.Zuiko Digital ED 45mm f/1.2 PRO weighs a smidge under 1 lb (14.46 ounces). The Canon EF 85mm f/1.2L II USM, a full-frame counterpart to the Olympus M.Zuiko Digital ED 45mm f/1.2 PRO, weighs 2.6 lb. The total weight of all five of our Olympus, fast maximum aperture test lenses came to about 3.5 lb, which is less than a pound more than a single Canon L-series high-speed prime lens. If traveling with cameras and multiple lenses is a common practice for you, or if weight is an issue, this should serve as food for thought.
Why Fast Glass?
Wider apertures are the key to shooting sharp handheld photographs in low light. The wider the aperture, the faster your shutter speeds, and the faster the shutter speeds, the better your chances of freezing the action. Wider apertures also mean lower ISOs, so cleaner and, therefore, sharper images are captured. The advantages of shooting with wider-aperture lenses, however, go well beyond low-light shooting.
Selective Focus
The degree to which you can isolate your subject from the foreground and/or background is greatly determined by the lens aperture and the distance between your subject and the camera position. The wider the aperture, the greater the control. And even though the MFT format is half the size of full-frame sensors, each of these wide-aperture lenses enables a great degree of selective focusing, most notably at closer focusing distances.
Wider-aperture “Sweet Spot”
With few exceptions, the resolving power of a lens peaks when the aperture is stopped down a few stops from maximum aperture. You might have more in focus if you stop down further, but whatever is in focus may or may not be as sharp as what you get a couple of stops down from wide open.
In the case of an f/1.4 lens, peak performance could be at about f/4. A lens with a variable f/3.5-5.6 maximum aperture kit lens set to the long side of the zoom range (f/5.6) may not hit peak performance until you stop down to f/11-16. Unless you’re shooting under bright, midday sun, this doesn’t work in your favor.
Faster, wider-aperture lenses enable you to stop the lens down while maintaining still quite large apertures for capturing more light, maintaining manageable shutter speeds, and improving sharpness.
Granted, wider-aperture lenses are invariably larger, heavier, and costlier than their smaller-aperture counterparts, but I prefer to view the additional weight, mass, and cost as the trade-off for the advantages of wider-aperture lenses.
The following is a selection of five wide-aperture prime lenses from Olympus with samples of images they can capture when used with an Olympus OM-D E-M1 Mark II.
Olympus M.Zuiko Digital ED 17mm f/1.2 PRO
The widest lens in our review is the Olympus M.Zuiko Digital ED 17mm f/1.2 PRO, which, with an angle of view of 65°, has a field of view similar to a 34mm lens on a full-frame camera. This weather-resistant, semi-wide-angle lens contains 15 elements in 11 groups including single EDA, ED-DSA, Super HR, and aspheric elements and a quartet of ED lens elements for maximized image quality. Other features include a Movie & Still Compatible (MSC) AF system, a manual focus clutch, Z Nano lens coatings, 62mm filter threads, and internal focusing. Minimum focus distance for this lens is 7.87" with a maximum reproduction ratio of 1:6.7. Though hefty, the Olympus M.Zuiko Digital ED 17mm f/1.2 PRO is notably light compared its full-frame 35mm f/1.2 equivalents.
Olympus M.Zuiko Digital 25mm f/1.8
The Olympus M.Zuiko Digital 25mm f/1.8, which is available in a choice of black or silver, is a nifty fifty for MFT shooters. Protruding from the camera a mere 1.6", it’s also the smallest lens in our field test. This compact f/1.8 normal lens has a 47° AoV, dual aspheric lens elements, a still and video-friendly MSC AF system, a minimum focus distance of 9.4" (1:8.3), and a rounded, 7-blade diaphragm. If there’s a downside to the M.Zuiko Digital 25mm f/1.8, it would have to be that it’s so tiny I kept losing it in my bag—it’s that small.
Olympus M.Zuiko Digital 45mm f/1.8
Olympus offers a choice of fast 45mm lenses, the smallest of which is the Olympus M.Zuiko Digital 45mm f/1.8. Available in a choice of black and chrome, this 90mm-equivalent lens has a 27° AoV, twin Extra-High Refractive elements, an MSC AF system, a 7-bladed diaphragm, and a minimum focusing distance of 1.64' (1:9.09). The M.Zuiko Digital 45mm f/1.8 is a mere 1.81" long and weighs 4.09 ounces, which makes it a laughably small, light, and fast portrait lens.
Olympus M.Zuiko Digital ED 45mm f/1.2 PRO
The Olympus M.Zuiko Digital ED 45mm f/1.2 PRO is a true handful. It’s twice as fast, twice as long, and nearly triple the weight of the notably smaller and lighter Olympus M.Zuiko Digital 45mm f/1.8 version. Nonetheless, I really enjoyed shooting with this lens.
To keep definition, color, contrast, chromatic aberrations, and flair under control, the Olympus M.Zuiko Digital ED 45mm f/1.2 PRO contains single ED and aspheric elements and a quartet of High Refractive Index elements. In total, the M.Zuiko Digital ED 45mm f/1/2 PRO contains 14 elements in 10 groups.
In addition to weather-resistant construction, the M.Zuiko Digital ED 45mm f/1.2 PRO features Z Coating Nano technologies, an MSC High-Speed Imager AF system, internal focusing, and a manual focus clutch. The Olympus M.Zuiko Digital ED 45mm f/1.2 PRO focuses down to 1.64' (1:10) and features a 9-bladed aperture.
Olympus M.Zuiko Digital ED 75mm f/1.8
Though I tend to gravitate toward wide-angle lenses, this didn’t stop me from falling in love with the Olympus M.Zuiko Digital ED 75mm f/1.8. With an FoV equivalency of a full-frame 150mm lens, I found myself capturing one strong image after another with this honey of a very fast telephoto lens.
The Olympus M.Zuiko Digital ED 75mm f/1.8 contains a trio of Extra-Low dispersion elements and dual High Refractive Index lens elements, each with ZERO Lens Coatings for optimized image quality. Other features include an MSC AF system, a minimum focusing distance of 2.76' (1:10), and a 9-bladed aperture. The best part of the equation is that this is a 150mm f/1.8 equivalent lens and it only weighs 10.7 ounces! Life is good.
Are you a Micro Four Thirds shooter? If so, do you have any experience with any of these lenses? We’d like to hear your thoughts.
6 Comments
Fundamental error or wrong marketing you just can't say that a 75mm f1.8 is equivalent to 150mm f1.8 in reality it's a 150mm f3.6 !!!!
This is a misconception that many people have. A 4/3 75mm f/1.8 lens has the depth of field of a full frame 150mm f/3.6. But the 4/3 75mm f/1.8 lens does pass f/1.8 of light. It is optically an f/1.8 lens.
How is the 75mm f1.8 not a f,3.6 lens?
As Brett R. pointed out above, optically speaking the lenses will transmit the light of f/1.8. The aperture, or f-stop, is actually mathematically determined and not affected by things such as sensor size. If we wanted to discuss equivalence, a 75mm f/1.8 lens on MFT would provide the same field of view and depth of field as a 150mm f/3.6 lens. However, light transmission would remain the same as f/1.8.
Thank you for explaining this in such a clear way. But why is this important? Is it a distinction without a difference? Obviously field of view and depth of field matter to photographers. But why is equivalent light transmission important? Does that mean that an f/1.8 MFT lens is just as fast as a traditional f/1.8 lens in identical lighting? Or is the speed also cut in half because only a fraction of the light is falling on the smaller sensor?
Hi Anthony,
Great question and, as you can see above, there is some confusion on this topic.
The maximum aperture f/stop is calculated based on the measurement of the opening of the diaphragm and the focal length of the lens. There is no factor for sensor size.
This is why handheld light meters do not have a setting for different sized sensors. f/1.8 is f/1.8 regardless of the camera the lens is attached to when it comes to light gathering.
Thanks for reading!