60 mm f/2.8 2x macro lenses
Until the 1960s and 1970s, several camera and microscope makers marketed dedicated lenses for photomacrography. Typically, these lenses were meant to be mounted on bellows or stacks of extension tubes, and did not have a focusing helicoid (some Olympus lenses for photomacrography did have a focusing ring, but of limited range and useful only for fine adjustments). Brands like Zeiss, Leitz, Olympus and Nikon even had dedicated photomacrography stands and dozens of accessories. By the 1980s and 1990s, Olympus was the only "survivor" still marketing such a system, compatible with its OM SLR cameras.
By the turn of the century, all these systems had been discontinued, and the equipment still being produced consisted mostly of industrial zoom video lenses and industrial microscopes, either unsuitable for high-quality imaging or priced well above the reach of ordinary photographers (and many university labs). While many stereomicroscopes of the time offered a way to attach a camera, only a few, high-end stereomicroscopes are really suitable for high-quality digital imaging, and likewise expensive. Rodenstock and Schneider continued to offer a shrinking range of good enlarger and copy lenses useful in photomacrography. Schneider still offers a limited range of needlessly expensive lenses in a special mount that makes their use in digital imaging more efficient, and a handful of dedicated accessories.
For about a decade after the turn of the century, photomacrographers were largely relegated to hunting for legacy lenses and equipment on eBay, some of them dating up to half a century. The few exceptions to the comparative dearth of good but affordable photomacrographic equipment around 2000-2010 included two lenses that did not require the use of bellows or extension tubes. The Canon MP-E 65 mm, with a magnification range between 1x and 5x, was released in 1999 and is still in production, although rumors of its impending demise are periodically discussed on forums. Minolta offered a comparable, far less popular lens, discontinued several years ago. Both lenses require the use of compatible cameras of the same brand, and cannot be adapted to other cameras.
During the last half century, there has been no shortage of dedicated macro lenses for SLRs and DSCs (Digital System Camera). These lenses typically focus between infinity and a magnification of 1x (in a few cases 0.5x) and are almost always of excellent optical quality. I am excluding so-called "macro zoom" lenses from this discussion. They are an old marketing gimmick for which only beginner photographers are likely to fall nowadays. I am also excluding high-quality lenses capable of close-up focusing but not reaching 1x (e.g. the excellent Olympus 300 mm f/4). Optical attachments that mount in front of, or at the rear of, an ordinary lens are likewise outside this discussion.
In the last 2-3 years, however, we started to see new, affordable macro and photomacrography lenses that break the above pattern in one or more ways.
The Olympus 30 mm f/3.5 macro lens is such an example. It provides continuous focusing between infinity and 1.25x, thus slightly bridging the conventional barrier between macrophotography and photomacrography lenses. This lens is handicapped by an excessively short working distance and wide lens front, which make a satisfactory illumination of the subject largely impossible, but is hopefully a sign of better things to come from Olympus.
Around 2012 Yasuhara (Japan) introduced the Nanoha 5x lens for Micro 4/3 and other mirrorless cameras, capable of 4x to 5x magnification (no focal length was specified, but without access to this lens I would hazard a 20 mm guess), and a fastest effective aperture of f/11 (so the nominal aperture should be around f/2-2.8). It has an integrated (but removable) USB-powered illuminator with three LEDs.
In 2016, the Chinese lens manufacturer Zongyi introduced a 20 mm f/2 Mitakon with a restricted magnification range (4x to 4.5x) that directly mounts on DSLR camera bodies. This lens was possibly meant to offer a 4x to 5x range, but problems with performance at 5x forced the intended range to be cut late in the design stage. The three-blade iris of this lens is its main weakness, although there is no good reason for stopping down beyond one stop. The optical formula of this lens differs from the Yasuhara Nanoha 5x.
In 2015, Venus Optical (China) introduced a Laowa 60 mm f/2.8 focusing all the way from infinity to 2x and employing a few unique design peculiarities (see below). In 2016, it also introduced a 15 mm f/4 macro (infinity to 1x).
More recently, 60 mm f/2.8 Chinese lenses of a design apparently very similar to the Laowa 60 mm started to be available, first on eBay and subsequently from other sources. This page discusses in detail the Laowa 60 mm and one of its apparent "clones", the Oshiro 60 mm f/2.8 2x. The Oshiro lens costs less than half the normal price of the Laowa.
A third 60 mm f/2.8 2x lens is also commonly available on eBay and other sources, and is on eBay slightly cheaper than the Oshiro 60 mm. It is mostly sold without any brand name (it is easiest to find by searching for "super macro 60mm" on eBay), but recently specimens branded as Camdiox 62 mm f/2.9 have appeared, sold in western countries at almost twice the price of the unbranded ones from eBay.
The focal length and aperture values specified by Camdiox, even assuming they are correct, are not significantly different from those of the no-name lens, and I regard them as either an example of German nit-picking, or a marketing ploy to present their branded lens as different from the unbranded ones on eBay. It is common for lens manufacturers to round up or down the FL and aperture specifications of a lens by up to 10%, in order to make them easier to remember. I am confident that this Camdiox lens is the very same model as the unbranded ones. This model is also sold as the Bresser 60 mm f/2.8 2:1, although it may not be branded so on the lens itself.
The image quality provided by these lenses will be the subject of a separate web page.
In this discussion, I use the term macrophotography to indicate photography at an on-sensor magnification between 0.1x and 1x, and photomacrography to indicate photography with a "lens" (more specifically, a non-compound optical system) at on-sensor magnifications above 1x. Other definitions of these terms exist, as well as other terms used to denote the same things.
In macrophotography and photomacrography, the "focus ring" of macro lenses is generally not used for focusing. Instead, in normal operation, the ring is used to set the desired magnification. Focusing is subsequently achieved by moving the lens and camera back and forth as a whole, without touching the ring. For this reason, on this page I call it "magnification ring".
In operation below approximately 0.1x, e.g. portraits, landscapes and other general subjects at a distance, this ring is instead used for focusing, just as the focus ring of ordinary (non-macro) lenses.
Shared features among 60 mm 2x lenses
At 2x, the effective aperture is 3 stops more than the nominal aperture. This is just how optics work, and lens makers have no design choice in this respect. Depth of field is also dictated by the laws of optics and depends only on aperture and magnification. It does not depend on lens focal length or lens design, so no "magic" is possible in this respect, either.
Laowa 60 mm
Packaging - The lens comes vacuum-packaged in a sturdy plastic bag of a semi-transparent type I do not remember seeing before. The bagged lens is then placed into a neoprene storage pouch and in a corrugated cardboard box that contains also user manual (Chinese and English) and a Chinese-only warranty card. There are no throw-away packaging materials except the box. The box carries no lens serial number. The warranty card is also blank. The front and rear lens caps are third-party, unbranded ones.
Mechanics - This lens feels reassuringly solid, and the machined metal magnification ring contributes to this feel. All visible parts are made of blackened metal, except the chrome-plated metal bayonet. There is a slightly uneven, grating feel when turning the magnification ring.
The lens serial number is screen-printed on the front of a baffle with a roughly rectangular cutout, mounted immediately within the 62 mm filter mount. This baffle is an integral and important part of the lens design (see below). All lettering on the lens is screen-printed in white.
The aperture ring has full-stop clicks only, but it is possible to set half-stops if you really need. The aperture ring indicates nominal aperture (i.e., it does not compensate for focus throw).
Optics - Venus Optical specifies that the lens uses 9 elements in 7 groups, in two independently moving subassemblies. The rear subassembly appears to contain two air-spaced elements (or cemented groups), judging from reflections of light sources. The rest of the elements, with the diaphragm attached immediately at the rear, are in the front subassembly. Both subassemblies are moved on separate cams by the magnification ring.
The iris seems to have 14 blades.
The lens coatings are multi-layer, and the different colors of the reflections indicate that different types of coatings are used on different elements.
With the lens focused at infinity, both groups are in their rearmost position. Focusing closer/increasing the magnification moves the rear group a little forward, while the front group moves a lot more in the same direction. If you look into the lens through the cutout in the front baffle, when focused at infinity the front element is deeply recessed within the barrel, and moves forward to become flush with the baffle at 2x.
In practice, the barrel and baffle function as a deep lens shade for most of the magnification range, while this lens shade in practice disappears when working distance shortens and every millimeter of distance between lens and subject counts and must not be wasted. A similar principle is used in other macro lenses, e.g. the AF Micro Nikkor 105 mm f/2.8 and 60 mm f/2.8 (these two lenses also extend the total length of the barrel, in addition to moving forward the front optical group within the barrel, so they are mechanically more complex than the Laowa lens). Subsequent models of these Nikon lenses use internal focusing instead, and the front element remains completely unsheltered at the front of the barrel at all magnifications. Earlier models move the barrel as a whole in and out, and any built-in recess of the front element remains unchanged at all magnifications, and in the way of illumination at high magnification.
Oshiro 60 mm
Packaging - The lens is packaged in a relatively large corrugated cardboard box, between two preformed plastic half-shells and enclosed in an ordinary, non-sealed plastic bag.
Prominent on each side of the box is a clear picture of the Laowa 60 mm lens (sic!). The front and rear caps are third-party, unbranded ones (very similar but not identical to the ones used in the Laowa 60 mm lens). The box also contains the English user manual and a padded neoprene bag, thinner and cheaper than the one accompanying the Laowa 60 mm.
The user manual starts with the same picture of the Laowa 60 mm (sic!) as on the box. The Laowa brand is not visible in the picture, but there is no possibility of misinterpreting this picture. This picture is not of the Oshiro 60 mm lens. A drawing of the lens later in the manual is schematic, but closer to the Laowa lens than to the Oshiro.
The full name of the lens in the user manual, just above the picture of the Laowa lens, is "Oshiro 60 mm f/2.8 2:1 LD UNC Ultra Macro Lens". The lettering on the box uses a slightly different ordering.
Perhaps the Oshiro people think that buyers will be so easily fooled by the pictures, in spite of the fact that they are going to open the box and see for themselves that they got a different lens? If so, Oshiro may be right. Some owners of the Oshiro lens have indeed commented online that their lens is somewhat different than in the pictures, but these owners apparently did not bother to ask themselves why, and just assumed that the external lens design had been tweaked and that the box reflected an earlier design.
The Oshiro web site shows no less than four different pictures of the Laowa lens. Nowhere on the Oshiro web site or literature you can see the actual Oshiro 60 mm lens. I have seen online reviews and posts about the Oshiro lens that also show the Laowa lens, except for a couple of videos that show somebody handling an Oshiro lens in the distance.
The actual appearance of the Oshiro lens seems to be a great mystery. Give a good look at the pictures of the Oshiro lens on this page, because they might be among the few you will ever see.
Mechanics - This lens is perceptibly lighter (421 g) than the Laowa 60 mm (517 g). My specimen of the Oshiro lens has a Nikon F mount, which has a lower diameter than the Canon EOS bayonet, and the barrel in Nikon mount is slightly shorter than the Canon equivalent because of the different registration distance. These differences do not fully explain the different weight. The use of a rubber sleeve mounted on the magnification ring (machined metal in the Laowa) makes some difference, as well as the use of an apparently thinner barrel in the Oshiro and the presence of a thick round baffle at the rear of the Laowa lens. The front of the inner optical subassembly in the Oshiro seems to be injection-molded plastic, with a broadly conical built-in lens shade. Nothing in the Oshiro barrel and controls is identical to the Laowa. There are differences in size and placement of all visible mechanical parts.
The front baffle is also different. While the Laowa baffle is a thin metal plate with a cutout, the baffle of the Oshiro is painted in black on the back of thin glass plate permanently mounted behind a retaining ring in the filter mount. The glass is AR-coated, but exposed to ambient light. In some illumination conditions, it may invite flare and lower contrast. On the other hand, this glass protects the mechanical innards of the lens. The transmission of the aperture control is longer in the Oshiro, and the internal optical subassembly is rotated half-turn within the barrel, compared to the Laowa.
Given the short working distance of these lenses, something might drop through the open front baffle of the Laowa lens and into the lens barrel, and cause some mischief. Dust entering the baffle may get stuck to the abundant grease on the inner surface of the barrel and literally "gum up the works". All visible internal surfaces in both lenses are abundantly greased, except the front and rear of the optical subassemblies. Some excess grease is raked up by the edge of the front subassembly and collects around its perimeter.
If you are really worried about contamination of the barrel interior in the Laowa (and no-name) lenses, you can mount a high-quality, AR coated and preferably thin protector or UV filter on the 62 mm filter ring of the lens. You may even extract the glass disk of the filter from its mount, put the glass in the filter mount of the lens and fix it in place semi-permanently with the retaining ring of the filter. This reduces the loss of working distance caused by the metal ring of the filter, and makes the Laowa lens as protected as the Oshiro.
The grating feel when turning the magnification ring of the Oshiro lens is more pronounced than in the Laowa lens.
The aperture ring lacks click-stops.
Optics - Oshiro specifies that the lens uses 9 elements in 7 groups, in two independently moving subassemblies. The rear subassembly appears to contain two air-spaced elements (or cemented groups), judging from reflections of light sources. The similarity with the Laowa ends here. The diameter of the rear element is slightly larger in the Oshiro, and the curvature of the optical surfaces in the rear subassembly (as indirectly indicated by reflections of light sources) is different in the two lenses. The distance between front and rear optical surfaces in the Oshiro at 2x seems to be slightly shorter (by a couple of mm) than in the Laowa. The curvature of the front optical surface is different in the two lenses. The distance between the front and second elements in the Oshiro seems significantly larger than in the Laowa.
The iris seems to have 14 blades. The blades are slightly more reflective than in the Laowa, but I don't think this makes a significant difference.
All lens coatings in this lens seem to be of the same type or similar types, with greenish/bluish reflections, with the possible exceptions of coatings of slightly different colors on one optical surface in the rear subassembly and one in the front subassembly.
No-name 60 mm
My observations on this lens are only based on online illustrations and reviews. Consequently, I am far less certain about features of this lens than of the two preceding lenses.
Packaging - This lens comes in a corrugated cardboard box similar in size to the Oshiro's. A padded pouch is also supplied. Unlike the Oshiro's package, the lens pictures on the outside of the package of the no-name lens are of the actual lens model contained in the package.
Mechanics - The rubber sleeve on the magnification ring seems to sit loosely in a few pictures by sellers of this lens available on the web (not just the pictures of this lens on the Venus Optical Facebook page, which are made specifically to prove this point).
A couple of pictures in ads by sellers show a defective lens specimen with a loose, skewed ring immediately in front of the aperture ring that leaves a broad open gap in the external surface of the barrel.
The cutout on the front baffle is shaped differently than in the two preceding lenses. This is the easiest way to recognize the present lens. The rib sculpture on the rubber of the magnification ring also differs from the corresponding rubber sleeve of the Oshiro lens. The retaining rings on the front subassembly, as visible through the baffle, are more similar to the Laowa than Oshiro lens. A few other distinctive elements might become evident by comparing this lens side-by-side with the other two.
Clones, knockoffs or copies?
On their Facebook page, Venus Optical makes it clear that they are not making or marketing the Bresser/Camdiox/no-brand 60 mm lens, and that they regard them as unauthorized copies of inferior quality. They do not specifically mention or illustrate the Oshiro lens.
The Oshiro is obviously not a rebranded Laowa, given the numerous mechanical differences. Unless I am wrong on each and every of my several observations about the optics, the Laowa and Oshiro lenses also use different optics.
Oshiro is a brand of lenses offering a very limited range of products: five lens models, according to their web site at the time of writing. I am quite sure that their 8 mm f/3.5 fisheye is a rebranded Samyang, in itself quite a good lens, or a clone/knockoff thereof. The Oshiro 500 mm f/6.3 is suspiciously similar to low-price lenses of very basic quality, offered by the boatload on eBay and Chinese sites. The price of this Oshiro lens is likewise low. The Oshiro 35 mm and 135 mm lenses may also be rebranded items, although I do not positively recognize them as such from the pictures on the Oshiro web site.
It is therefore likely that the Oshiro 60 mm macro is not manufactured by Oshiro, and is instead a rebranded item. Albeit, designed and produced by whom?
I am not sure about the Bresser/Camdiox/no-brand 60 mm lens. It is obviously not a rebranded Laowa. It is not a rebranded Oshiro, either. At this time, I don't know if the no-brand lens uses the same optics as either of the above lenses, or yet a different, third optical formula.
With modern software for lens design, like Zemax, in principle it is possible to read in the optical formula of a lens, published e.g. in a patent description, and then tweak and re-optimize it with slightly different parameters to obtain a slightly different design with similar optical properties. This might help to avoid prosecution for patent infringement, since there is in principle an infinite number of ways to tweak the optical formula of a lens. This might also explain while we have two or three lenses from different companies that use suspiciously similar, but not identical, lens schemes (same general scheme with 9 elements in 7 groups and 2 independently moving subassemblies, same focal length, same speed, same focusing capabilities).
If the patented optical scheme (I assume it is Venus Optical's) was originally based on a (perhaps simpler) optical scheme in the public domain, it would be difficult to prosecute the copycats. Their defense may be along the lines that they, too, started their development from the same, publicly available scheme, and that their end result just happens to be similar to Laowa's lens but sufficiently distinct not to constitute patent infringement. I have not seen the Laowa 60 mm patent, and don't know whether it contains a sufficient number of alternative lens schemes to cover most of the easiest design variations.
Before directly comparing the Venus Laowa 60 mm and Oshiro 60 mm lenses, I strongly suspected that one of them was a knockoff of the other, with the Oshiro using the same optics of the Laowa, and possibly cheaper element coatings, mounted in a cheaper barrel.
This, however, is not what I found. All evidence suggests that the Oshiro is instead a copycat using a similar lens design but different optics.
The strangest detail in this strange story is that Oshiro consistently uses pictures of the Laowa lens on its web site, on the box of the Oshiro lens, and in the user manual of the Oshiro lens, despite the visible differences. Why go through the pain of designing and producing a new lens, and then use pictures of somebody else's lens? Are these shenanigans worth a potential market niche of maybe a couple of thousand sales a year, or is there more to this story that we don't know yet?