Olympus 60 mm f/2.8 macro
Macro lens choices for Micro 4/3
Until Olympus started to sell the 60 mm f/2.8 macro lens for Micro 4/3 cameras, users of this format had three choices for a macro lens:
The image quality of the Olympus 50 mm f/2 macro lens is very good, but its autofocus is so painfully slow on a Micro 4/3 camera that it may be better to save money and use one of the many cheaper third-party macro lenses in manual mode. In addition, this lens only focuses to 0.5x, and requires a dedicated 4/3 extension ring to focus between 0.5x and 1x. This breaks the focusing range into two ranges separated by a manual insertion or removal of extension tube, right at a point where it would be most useful to have a continuous focusing range. It seems incongruous of Olympus to repeat in a modern lens the main practical fault of several legacy models of macro lenses, which also need an extension ring to focus past 0.5x.
The Panasonic/Leica 45 mm is a good lens, but a bit expensive and with a somewhat too short focal length to give an optimal working distance (about 60 mm at 1x), especially for use in the field.
The last solution is actually quite reasonable and still relevant, because plenty of excellent macro lenses are available at reasonable prices on the second-hand market (including some models that focus uninterrupted between infinity and 1x), and the lack of autofocus and automatic aperture are not very serious handicaps in studio macro photography. However, automatic aperture does help to manually focus quickly and accurately, especially when hand-holding in the field, and I find autofocus desirable when using a lens in generic photography and in the close-up range.
Comparing macro lenses for different formats
It is not straightforward to compare macro lenses designed for different sensor formats, for a number of factors. Foremost is the fact that 1x on full-frame actually represents the same field of view (FoV), on the subject side, as 0.5x on Micro 4/3. Second is that the sensor size, in addition to the FoV at a given magnification, also affects the depth of field (DoF). Third, at the same image resolution in pixels, aperture affects DoF and diffraction to different extents, because of the different physical sensor sizes. And, like this was not enough, all these factors are interdependent, so it is not possible to say "let's compare these lenses in the same conditions", because conditions simply cannot be the same - one or another of the above factors always differs.
The differences in DoF and diffraction related to sensor size are more pronounced in generic photography of distant subjects than in macro photography. At 1x, the differences are negligible and can be ignored (except for the complication that 1x on full-frame should really be compared with 0.5x on Micro 4/3, which slightly changes the rules in the middle of the game).
These differences are modest but still worth knowing about in close-up photography. In this range, it can be stated that Micro 4/3 lenses, at the same FoV and aperture, produce a slightly higher DoF than lenses for larger sensors. Micro 4/3 lenses and sensors, on the other hand, are also slightly more affected by diffraction than larger formats. In practice, a simple rule-of-thumb for photographers migrating from APS-C or full-frame cameras to Micro 4/3 is remembering to open the lens aperture by about a half-stop or one stop, respectively, in order to produce comparable results. For instance, in close-up photography, while the optimal compromise between high DoF and high resolution is usually around nominal f/11 on a full-frame sensor, f/8 is a better choice in Micro 4/3.
Yet another difficulty in comparing macro lenses for different sensor sizes is that lenses of different focal lengths produce different working distances. While a 150 mm lens on a full-frame camera produces exactly the same FoV as a 75 mm on a Micro 4/3 when used in the photography of distant subjects, these two lenses in macro photography provide quite different working distances, even when the different magnifications necessary to achieve the same FoV are taken into account. Therefore, for photographing dangerous, easily scared or otherwise unapproachable subjects, macro lenses of long focal lengths remain necessary also with Micro 4/3 cameras. The problem, of course, is that at present no such Micro 4/3 lenses are available. Olympus (or Sigma/Tamron/Tokina, for that matter), if you are reading this, how about a 150 or 180 mm Micro 4/3 macro lens next? As long as it provides the same image quality as the Olympus 60 mm and has internal focusing and a solid, built-in tripod collar, you can already put me on the list for one. I can gladly accept an f/3.5 or f/4 lens speed, to cut down on weight and cost. Anyway, I never use a macro lens fully open. However, don't believe that you can get away with a full-frame or APS-C lens design with a Micro 4/3 bayonet stuck on as an afterthought. I want a lens designed from the start for Micro 4/3, like the Olympus 60 mm.
An advantage of Micro 4/3, as already mentioned, is that the FoV at 1x is exactly half the FoV of a 1x lens on full-frame. Very few macro lenses for full-frame can exceed 1x (at present only the Canon MP-E 65 mm does, but this is a specialty lens that cannot focus to infinity). In practice, the Olympus 60 mm gives to a Micro 4/3 camera the same capabilities that would require an ordinary macro lens and a long extension tube with larger format DSLRs.
The Olympus 60 mm macro
This lens was announced several months ago, and became the last in a batch of Olympus and Panasonic lens models announced in the same period to actually become available. At the time of writing, some large online sellers like Amazon still have not started shipping it, but it has already been available from other sources for a couple of months.
This is a relatively cheap lens model, considering that it comes from a well-known camera brand and, in addition, it is a macro lens. This type of lens is generally known for very high optical performance and for not being addressed to the mass consumer market. Both factors typically combine to make the item's price comparatively high. Instead, the 60 mm is already a couple of hundred US$ cheaper than the Panasonic/Leica 45 mm macro and is likely to further drop in price after a few months, so choosing it over the 45 mm is a no brainer.
I will not publish here any pixel-splitting tests and charts, because plenty are already available on other sites, and they all tell the same story: as macro lenses go, the Olympus 60 mm is right in the top notch category in resolution, contrast and lack of aberrations (albeit, see the test near the bottom of this page, and yes, I lied when I said I was not providing any tests).
Below, I can offer pictures of a few features of this lens that are not normally visible in the one or two stock Olympus pictures that some of the other reviewers seem to be fond of repeating over and over again on their sites, instead of publishing their own pictures of the lens.
This lens looks unusually long, almost telephoto-like in pictures, but pictures are slightly misleading because of the overall small sizes of Micro 4/3 cameras and lenses. First of all, this lens has a very slender barrel compared to lenses for full-frame and APS-C cameras. Second, we must keep in mind that the Micro 4/3 format has a low registration distance that the lens has to make up for in increased length. When put side-by-side with the Nikon AF Micro Nikkor 105 mm f/2.8, which is roughly comparable in practical use and is not one of the largest macro lenses of this focal length, the true size of the Olympus lens becomes more apparent.
So far, Olympus seems to be uncertain of what color to use for their Micro 4/3 lenses. It is currently selling a few lens models only in black barrels, a few others only in chrome barrels and yet a few more in slightly champagne-colored silvery barrels. Several of its consumer zooms are available in both black and chrome. It recently even started offering the 12 mm f/2, originally available in champagne finish, in a new black "luxury" version, cheaper to produce but sold at a higher price together with a non-optional matching lens shade. The Olympus 60 mm f/2.8 is so far only available in black, which is a reasonable choice from a utilitarian point of view.
The barrel is made of molded polycarbonate plastic, but because the focus is internal there is none of the "wobble" usually associated with plastic lenses. I cannot see molding lines on the barrel in my specimen, although they are mentioned in at least one other review. An unusual detail is that the pattern on the focusing ring (above) is neither plastic nor rubber, but instead a machined and blackened metal sleeve. The anodizing/blackening is not quite perfectly black, and the metal part appears lighter than the rest of the barrel and slightly bluish in artificial light (but not in the above picture taken with electronic flash).
The lens weight is only 185 g in spite of the numerous optical elements, so this is a lens that will occupy a permanent place in my camera bag. In comparison, the Nikon Micro Nikkor 60 mm f/2.8 G weighs 425 g, and the corresponding AF-D model 447 g, i.e., more than twice as much. The AF Micro Nikkor 105 mm f/2.8 pictured above is even heavier at 556 g.
The Olympus 60 mm is weather resistant, unlike most of the current Micro 4/3 lenses. Except for the rubber gasket around the lens mount (above picture), the weather sealing is of course invisible. Used on a weather-resistant body like the Olympus OM-D E-M5 or Panasonic GH3, it makes it practical to shoot in moist and even dripping environments without worries, as long as the camera and lens are dried in a sheltered environment (e.g., under the protection of a raincoat) before changing lenses in the middle of a field session. Like all Olympus Micro 4/3 lenses, the 60 mm has no built-in image stabilization and relies on the camera body to provide this function. Image stabilization in macro photography is (by necessity) much less effective than in generic photography, and should be regarded mainly as a way to make framing and focusing easier while hand-holding, rather than a way to allow longer exposures.
The front of the lens barrel displays a prominent bayonet mount for a dedicated and overpriced lens shade, offered for separate purchase. This dedicated shade can retract by sliding back over the front of the lens barrel without dismounting - which makes the focus ring inaccessible. Because of the price, and because I prefer to be able to use the focus ring when necessary, my copy of the 60 mm is not going to sport the original Olympus lens shade any time soon. Instead, I am using a shorter and narrower, no-name cylindrical lens shade that screws into the 46 mm filter thread and is short enough to be mostly out of the way even at 1x. The lens shade can still be removed if really necessary. A 49-52 mm step-up filter adapter can be attached at the front end of the lens shade to accept 52 mm filters, which is the filter size I decided to use as standard already in my Nikon days. With any luck, users of this lens who prefer the original type of lens shade will only have to wait until no-name knock-offs from China Inc. become available.
The 60 mm uses focus-by-wire, i.e., the focus ring operates a focusing motor and is not mechanically coupled to the internal lens mechanisms. The focusing ring is speed-sensitive, with a quick rotation performing a large amount of focus change and a slow rotation a correspondingly slower and more precise focusing. For this reason, the focus ring does not carry a distance scale. Instead, the approximate magnification and focus distance are displayed (with less precision) on a gauge visible through a transparent window. The transparent window seems to work like a dust magnet, as seen in the above picture.
The Olympus 12 mm f/2 and the recently announced 17 mm f/1.8 have a distance and DoF scale on its focus ring, and switch between autofocus and manual focus by push-pulling the focus ring. Doing so does not actually engage a real mechanical connection between focus ring and focusing mechanism - focusing is always by wire, but the focus ring rotates only by a fixed interval in manual focus mode, just like an old-fashioned lens with true manual focus. Therefore, it might have been possible to use the same solution on the 60 mm macro. This is either a missed opportunity for Olympus to make a truly excellent macro lens, or the result of an overwhelming desire to save on production costs. The 12 mm is quite a bit more expensive than the 60 mm, perhaps in part because of the design of the focus ring. However, many users of macro lenses would appreciate a true, accurate distance, magnification and DoF scale on the focusing ring. I would be ready to argue that this scale is more useful on a macro lens than on 12 and 17 mm wideangles.
A round rotary dial on the left side of the lens barrel selects the full focusing range or a limited one, which is useful when a faster autofocus is desired. This dial also has a momentary position that causes the lens to power-focus all the way to 1x, probably an all-first for a macro lens. It is not possible to leave the dial permanently set in this position. Turning the dial causes the lens to power-focus to the selected focusing range, if the current focus happens to be outside this range.
I don't remember seeing a rotary dial like this on any other lens - mainly sliding switches and press-buttons. In function, the rotary dial is not very different from a slide switch, but is perhaps more difficult to operate than the latter. However, some 4/3 Olympus lenses have rotary dials operated by grabbing a flattened handle with two fingers and twisting it. The trick with the Olympus 60 mm dial is to press its top with one fingertip and twist the whole hand. The dial is simply too small to grab with two fingers.
The working distance at 1x is around 90 mm, which is quite good for a lens with internal focusing of this focal length. The Nikon Micro Nikkor 60 mm f/2.8 AF G, for instance, has a considerably shorter working distance (48 mm) at the same magnification and nominal focal length. Olympus specifies only the minimum focus distance (190 mm), which is not the working distance but the distance between subject and sensor at 1x. Based on this, on the registration distance (19.2 mm) and on the physical length of the lens excluding the lens mount (82 mm), the working distance can be computed as 190 - 19.2 - 82 = 88.8 mm, which agrees well with my practical measurement.
The minimum focus distance of 190 mm deserves further discussion. At 1x, the focus distance of a lens is four times the lens focal length, at least for an infinitely thin lens, or a lens where the positions of the entrance and exit pupils coincide. Actual lenses with complex optical schemes can substantially deviate from this condition. Nonetheless, based on the focus distance at 1x, one can calculate a theoretical focal length of 47.5 mm. Lenses with internal focusing generally focus at close range by reducing their focal length, sometimes by dramatic amounts. This very rough calculation shows that Olympus has succeeded in limiting the focal length reduction to an unusually low amount, and thereby to provide a usefully high working distance in the macro range. Hopefully this will become a common trend in the design of third-generation macro lenses with internal focusing. In this discussion, I regard lenses like the Micro Nikkor 200 mm AF-S, Tamron 180 mm and Sigma 150 and 180 mm (f/3.5 model) as first-generation. In these models of relatively long nominal focal lengths, a reduction in actual focal length at close range does occur but is less troublesome than in shorter lenses. Second-generation lenses like the Nikon Micro Nikkor 105 G and 60 mm G have excessively low working distances, typically much shorter than the working distance of the Olympus 60 mm. The last lens may be regarded as third-generation because of its "return" to longer working distances in spite of its internal focus design. The Tamron 60 mm f/2 macro for APS-C cameras is even better in this respect, with a slightly higher working distance around 100 mm. It is a recent model and also deserves being classified as a third-generation macro lens with internal focus. The recently announced Tamron 90 mm f/2.8 macro with internal focus has a working distance of 139 mm, which also puts it in the same category.
The Olympus 60 mm uses 13 optical elements in 10 groups, with several exotic elements, and no less than three independently moving internal floating groups for focusing and reducing aberrations. The complex design is no doubt responsible for the excellent performance at all magnifications. Autofocus is precise and unusually fast for a macro lens, at least on the Olympus OM-D E-M5, and I do not mean this as a general compliment to macro lenses. The focus limiter should be used whenever a faster autofocus is necessary, just to reduce the time needed for the focus mechanism to rack all the way in the wrong direction and back (which does not happen nearly as often as with DSLR macro lenses).
Although autofocus in the macro range is traditionally regarded as an unnecessary luxury, and typically as a worse alternative than manual focusing, there is a good reason to use autofocus with this lens. The high resolution of which both the lens and the camera are capable make it difficult to achieve a fully correct focus manually. The use of live view at maximum magnification is almost obligatory to achieve a manual focus of the same precision possible with autofocus. In fact, a good focusing strategy with this lens is perhaps to operate in autofocus and to manually select the appropriate subject area for autofocus, for instance with touch-focus on the LCD screen.
Outside the macro range, the 60 mm is a good general-purpose prime lens, albeit not suitable for certain applications. These include portrait photography in ambient illumination, which often uses a low DoF to isolate the subject from the background. The Olympus 75 mm f/1.8 is a more natural choice in these cases. Fast autofocus while tracking quickly moving subjects is also a use for which other lenses are a better choice. Finally, if maximum resolution in the corners with distant subjects is an absolute requirement, the 60mm deserves a "very good" rating, albeit not "excellent". Other recent Olympus prime lenses are better in the corners, although you can see this only while pixel-peeping. However, even in these situations the 60mm easily beats any Micro 4/3 zoom lens that I have seen so far. The 60 mm is instead unreservedly excellent across the whole frame in the close-up and macro range, where it proves to be a full-blooded macro lens designed specifically for this application.
The above is a rather quaint actual sample shot at 1x, but good enough to give an idea of the results that can be expected in practice. Resolution at the center of the frame is obviously excellent. This is the type of resolution that I can see only with top-notch lenses like the Macro (not Micro) Nikkor. The extreme corners, instead, display an obvious chromatic aberration. However, this is easily corrected in post-processing (in the above case, with Adobe Lightroom). When this is done, resolution is lower than at the center, but still very good. In practical use, I will not have any problem using this lens for very demanding applications. Most modern lenses are designed to optically correct other aberrations at the expense of a higher transversal chromatic aberration, because this is the type of aberration that can be corrected most easily in post-production without producing artifacts.
The question is why the camera did not automatically correct the chromatic aberration. Olympus lenses mounted on Olympus cameras should do this as a matter of fact. Perhaps it has to do with the fact that I did not get around to upgrading the firmware of my OM-D M-D5, so it might be unable to recognize the latest lens models. For the moment, I am giving this problem the benefit of doubt and I expect it to disappear with one of my next firmware updates.
After seeking information, I did not find any positive statement to the effect that the Olympus OM-D E-M5 supports in-camera correction of transversal chromatic aberration. No such setting is available in the camera's configuration menus, for instance. On the contrary, several sources from 2010 and 2011 state that Olympus Micro 4/3 cameras do not provide this type of in-camera correction. Thus, it is possible that the OM-D E-M5, unlike Panasonic Micro 4/3 cameras, does not provide this capability, and that my expectations were wrong.
As a side effect, now that my still growing Micro 4/3 system includes the Olympus 60 mm, Panasonic 100-300 mm, Olympus 12 mm f/2, Samyang 7.5 mm and a "disposable" Panasonic 14-42 mm zoom with plastic lens mount, I am unlikely to be interested in a medium-long zoom like the Panasonic 35-100 mm f/2.8. A high-quality, no-compromises 15-45 zoom may still tempt me (the 12-50mm EZ M. Zuiko Digital ED is not quite good enough for me). Since such a lens does not exist yet, I can relax and wait. In the meantime, the Panasonic 14-42 is capable of quite adequate image quality in spite of being obviously targeted to the mass-market.
The Olympus 60 mm f/2.8 is the first native Micro 4/3 macro lens with a focal length and working distance suitable for both studio and field use. It provides excellent results in both close-up and macro photography, in spite of a slightly worse performance in the corners, which, however, still gives very good results. It is also very usable as a short telephoto lens for general photography. It is reasonably priced, cheaper that the Panasonic/Leica 45 mm macro for Micro 4/3 (which is so far the only other native macro lens for Micro 4/3) and the Olympus 50 mm f/2 for 4/3, and should be expected to further drop in price after a few months on the market. It is well-built but also remarkably lightweight, and smaller than pictures suggest. However, there is still a sore need for one or more native Micro 4/3 macro lenses of higher focal lengths (ideally 150 or 180 mm) for achieving higher working distances, especially on living subjects in the field.