The Laowa 25mm f/2.8 2.5x-5x Ultra-Macro (LW25) lens is a compact macro lens aimed at the photomacrography community and people who are not satisfied with the conventional macro lenses that usually only offer up to 1:1 life-sized reproduction ratios .
The lens itself retails for $399 USD, not inclusive of shipping. It is a little cheaper on the Chinese market, which is ¥2498. Laowa also offers two optional add-ons, a small LED ringlight and a lens collar. These are ¥168 and ¥150 respectively. These can be chosen as add-ons on Venus Optic’s website. The tripod collar is $30 and LED ring light is $39.90. I will talk about these two later.
When this lens was announced in April 2018, I approached Laowa asking for specifications. He kindly pointed me to a foreign distributor, and I was sent a copy of the lens for reviewing. They did not ask for anything in return. I simply used it and shared my thoughts with Laowa. I was also sent the small lens collar. I did not ask for the LED right light because it was not available at that time and I did not need it. I still use this lens up to this day.
Everything shared in this post will be my personal thoughts.
The box is presented nicely, with a piece of abstract artwork showing the lens. Inside the box, the lens and its collar sits nicely in specifically designed foam cutout, this is quite pleasing. The box doubles as a storage device, or the foam can be taken out and placed into say, a Pelican case .
The lens is very compact, it fits in my hand. I also grabbed some other lenses I had at the time for a size comparison.
Below is the size comparison:
As we can see, the lens itself is quite small when retracted. It does get longer as one “zooms in” or rather extends the reproduction ratio.
Also included in the box is a nice little booklet with some basic information and China’s complementary “passed” certificate thingo.
The lens is only intended for higher magnification macro and does not focus to infinity.
To illustrate the magnifications, this humorous photo can be found on the webpage:
The illuminati is completely exposed at 5x. If I use my Mitty 10x, we will surely see their globalist agenda, their crimes of putting fluorine in the water to turn the frogs…, and plans to hide the fact that the Earth is flat and all politicians are actually reptiles. Xp0s3d!
The Laowa 25mm lens is fully manual designed for a fullframe sensor, and weighs about 400 grams. It has 8 elements arranged in 6 group, one which is an extra-low dispersion (ED) element.
The lens features 8 aperture blades and does not allow front filters. It is offered in Nikon F, Canon EF, Pentax K, and Sony E mounts. A similar lens, the Canon MP-E 65mm f/2.8 1-5x is obviously only available for Canon EF mounts. Since the canon lens does not focus to infinity, it is actually possible to adapt it to a system with a longer flange distance, such as the Nikon F mount. A dummy adapter can be made with Ebay extension tubes. Aperture can be changed using a crude method where one presses down the depth of field preview button and immediately dismount the lens. This will cause the lens to be stuck at whatever aperture it was set to. The magnification will increase a bit and one is required to have two cameras if aperture is to be changed often.
An modular transfer function (MTF) curve is also available on the website. Unfortunately, only 2.5x at f/2.8 is available. For higher magnifications, we will be looking at higher resolutions (more lp/mm being resolvable). Please be aware that there are really no standards for MTF curves. Different manufactures use different display methods, and some (which I will not name) simply use the theoretical MTF curve generated by the optics software. Whilst the MFT curves can tell us a lot, the lens’ performance ultimately depends on the photographer and the techniques. An absolutely optically perfect lens will not be good in the hands of a person who does not know how to use it.
The lens feels very well built. The zoom ring is nicely damped and tight. It does not creep in vertical orientations. Aperture can be changed easily by fiddling with a small rotating dial at the front of the lens. This means there is no aperture linkage with the camera body, the camera does not know what the aperture is.
The lens cap is a bit weird, it is a twist lock type which is how lens hoods are usually attached. Grab the cap and twist it a bit to take it off. This means the cap is firmly held onto the lens. Laowa’s optional LED ring light add-on also mounts using the same method.
Magnifications are nicely marked on the lens barrel. A working distance  of about 45mm at 2.5x and 40mm at 5x was measured, this is adequate for lighting. The Mitutoyo 5x Mplan Apo objective lens has a working distance of 34mm.
Since the lens is light weight, it feels nicely balanced on a DSLR or mirrorless camera body. This makes the lens collar a redundant accessory. It is necessary for something as big as Canon’s MP-E 65mm lens but not for this lens. The lens collar features a nice arca-swiss compatible dovetail mount, but it is just too thin and does not grip onto the lens well enough. When mounting via the lens collar, the lens inadvertently tilts up a bit. This means the collar cannot adequately support the weight of the camera. Luckily the lens itself is small and light enough to get away without using the collar.
The lens does not accept any filters, and frankly, forget about using filters. I mounted a polariser onto the lens using some optomechanical components and the result was very bad. All kinds of weirdness was introduced. I will not recommend using this lens with a filter, it is better to focus on improving lighting and framing. A method with shortcomings cannot improve poor pictorial results that ultimately stem from bad techniques. This can be a problem if one uses ring flashes. Lack of filter threads will mean there is no simple way to attach the right flashes conventionally.
The lens is fully mechanical, no electronics are involved. Nikon’s ai and ai-s lenses can still communicate with the camera  through an aperture coupling prong, this lens however lacks that feature. Implementing something like that would require a more complicated design and thus increased price and potentially degrading image quality. This can be extremely problematic if one shoots in the field. At f/2.8, the viewfinder is already dark, when one increases the magnification, the viewfinder becomes darker because the “effective” aperture increases in numerical value. If the lens is set at f/5.6, or even f/2.8, it is practically unusable in the field. The viewfinder is far too dark. There are many LED flashlights (not speedlights) on the market that has 1/4”-20 threads. Buy one of those and a hotshoe accessory ballhead, the flashlight can be used as a focusing light to brighten up the viewfinder. This will have little to no effect on the use of speedlights in the field, since the shutter speed is usually somewhat high, at 1/200 or so. I have not used this lens in the field, so I am just speculating based on the little experience I have with reverse mounting certain lenses in the field.
Luckily Laowa offers a small LED ring light that can be used to assist focus. From what I can see, the ring light connects to an external battery bank which is kind of a hassle for someone like me. Unless I am on an extended trip, I do not bring one of those. Having the ring light built in will also increase the cost of the lens. The Laowa 24mm relay lens has that feature. An idea I have if I ever shoot in the field is a DIY ring light using fibre optics. I will use one of those readily available objective ring shaped optical illumators and mount it to a handheld flashlight. I always carry one with me for self-defence. The Klarus XT12 I use even has filter threads.
Setup and Subject
I mainly shoot under studio settings when it comes to photomacrography. I have built a stable vertical setup using various industrial surplus components imported from the USA.
For magnifications of 2x-5x, I primarily focus on mineral specimens from my personal collection and interesting objects around the house. Sometimes I find dead insects, which makes a good photographical interest after cleaning. I have found the Laowa lens to be the perfect candidate to showcase details in mineral specimens.
I use a technique called focus stacking. The software I use to combine the various images is Zerene Stacker. Depending on how deep the stack is, anywhere from 20 to 300+ images may be required for a stack. This hobby is definitely a shutter killer unless the camera has electronic shutter capabilities. One aspect that not everyone is aware of is raw output using the electronic shutter, some camera models do not produce lossless raw files when this mode is used. This fact is usually simply omitted by the manufacturer. Whether there is a difference between 12 bit and 14 bit can be another debate (there is). Programs such as Rawdigger can be used to determine the bit depth of raw files. Now, if manufactures pull a Hasselblad X1D, using funky interpolation algorithms to “fill in gaps” to achieve 16-bit… this is getting too complicated. Bottom line is, solely just looking at the images produced by a D850 under the different modes, I cannot see a difference.
I will not bore you with photos of resolution charts and gridded lines. On a D810, diffraction kicks in at f/5.6 for all magnifications. At f/2.8, there is slight softness. The optimal aperture to use this lens at is f/4. I wish the aperture ring is declicked, and there was a way to lock the aperture dial like industrial line scanner lenses.
At f/4, the corners are just slightly softer than the centre. This does not translate to much difference for me, as I usually focus stack anyway. The difference is really small. This is true for all magnifications between 2.5x and 5x.
The resolution of this lens is pretty good. At 2.5x, it resolves 250 lp/mm. At 5x, the lens resolves 360 lp/mm just fine. This is plentiful for field use and focus stacking. I do not have the photos of the resolution charts anymore, they are lost. I might retake the photos if people really wants to see it. It is not interesting at all, just a piece of quartz glass with various lines printed on.
What I do have is a set of comparisons created by a photomacrography hobbyist 一丈法師. He compared the Laowa 25mm lens to a Mitutoyo 5x Mplan Apo lens. The subject was a piece of silicon wafer.
The Mitutoyo 5x Mplan Apo lens is purchased new, which means this test is valid. A problem with used objectives is quality. The objective is usually salvaged from old disused or nonfunctional equipment with no guarantees of image quality. One would not know what kind of conditions the lens have went through prior to being offered on auction sites with the “as-is no returns” caveat. There is a reason why most of these used objectives comes out of either China, Korea, or the USA. The former two accepts a lot of industrial waste from labs and facilities that go bankrupt or upgrades their equipment.
Looking at the test results, it is abundantly clear that the Mitutoyo 5x objective wins the comparison. By winning, I mean it simply beats the Laowa 25mm configured at 5x in all pictorial aspects. The Mitutoyo 5x objective is slightly sharper, has greater resolution, and it is far better corrected for chromatic aberration. It will be hard for a consumer conventional zoom lens to beat a dedicated microscope objective. The test also illustrates the fact that the Laowa 25mm is sharper at f/4 than f/5.6. I will write a followup article comparing various apertures in detail, and comparing the Laowa 25mm to other options.
If one only wants to shoot at 5x, the Mitutoyo 5x Mplan Apo objective is the better choice. It is offered new at Thorlabs for $708.90. It can be imported new from Japan for cheaper prices. One problem will inevitably be transit. I purchased a Laowa 12mm f/2.8 D-Dreamer a while back, and it arrived decentered. The lens was tossed over the fence. Precious and delicate objective lenses cannot stand such torture. It is far better to have someone else physically bring the lens through, or just visit the country, source the objectives! Take the boxes away, toss the invoice (or *cough* inspect element and make a pdf out of it…) and mail the empty boxes to oneself, get one of those Pelican  cases (or similar) to protect the objectives during the flight. To be safer, the boxes can be mailed to a forwarder such as “shipito” which allows the user to declare the worth of the package, you know what I mean.
Since I do not own a Canon MP-E lens, I cannot compare the two. I have not seen a well controlled comparison either. From what I can gather, the Laowa 25mm lens wins. The MP-E however starts at 1x rather than 2.5x and has electronics to communicate with Canon camera bodies. Aperture can be set on the camera body and when metering, the lens is wide open at default, providing the brightest view possible. The Laowa 25mm lens is still good alternative for Canon’s discontinued MP-E lens.
Let us now talk about aberrations. This is where there is a shortcoming of the lens. The Laowa 25mm has some longitudinal chromatic aberration (LoCA) at all apertures, this is also referred to as “bokeh fringing”. The LoCA is not a problem if one decides to focus stack, but be aware if the stack consist of out of focus elements such as this one:
Above is a crop from the full resolution image zoomed in to 100%. Some clear green fringes can be seen. The full resolution photo can be found here.
The Laowa 25mm f/2.8 Ultra-Macro lens is packed with both versatility and quality. It serves as a great gateway to higher magnifications and adopting photomacrography as a serious hobby. The variable reproduction ratio provides access to a large range of photographical opportunities and allows different framing setups.
There are subjects that are more suited for higher magnifications, such as the scales of butterfly wings or eyes of a fruit fly. However, I have found that subjects such as minerals, shells, and small jumping spiders are better done with lower magnifications of around 3x to 5x. The idea that higher magnifications is always better is fallacious.
The most important aspect of photomacrography and photography in general will always be the human behind the camera, following by lighting techniques, and then equipment.
Find some subjects and give it a go under higher magnifications, something as mundane as chia seeds or sand may turn out to be absolutely amazing.
What I like about the lens:
- Competitive price
- Good build quality
- Great resolution and sharpness
- Long working distance
- Small size
What I do not care about (but others may find it to be a deal breaker):
- Lack of coupling/communication with the camera
- Manual focus 
- Lack of filter options  for mounting accessories
What I would like to see improved:
- LoCA performance
- Flimsy lens collar feels like an afterthought
I would like to thank the folks at Laowa for loaning me a copy to play with. I have been busy throughout the year. It is finally time for me to enjoy the summer, Christmas, and shooting!
All the stacks were shot on a Nikon D810, ISO 64, the aperture is set at f/4.
: There is no standard for magnifications. Some manufactures claim 1000x magnifications, turns out it is the real size VS size displayed on a monitor. Here, the reproduction ratio is determined by how large the subject is with respect to the camera sensor. A fullframe sensor is 36x24mm. If an object that is 24mm fills the fullframe sensor vertically, it is 1:1.
: Pelican cases are the carrying cases provided by the American company Pelican.
: Here, working distance is the distance from the subject to the front of the lens.
: This depends on the model. professional Nikon DSLR bodies have the aperture prong necessary to communicate with historical glass. Prosumer cameras such as the D7000, D7100, D7200, D300, and D300S has the mechanism as well. Nikon foolishly removed the mechanism on their D7500 “upgrade”, probably because they want people to justify buying the D500 which in all honesty is not much more expensive. The existence of the D7500 is weird. I personally cannot see why one would buy that over the D500.
: A camera needs sufficient light to auto-focus. Moreover, the auto-focus is useless for macro distances anyway. At such magnifications, any tiny movement will render the area of interest out of focus.
: A DIY idea is to ask Laowa for a spare lens cap, drill the middle section out, and forcibly push it into a filter step-up ring, then welding it on.