Macro lenses
The best lens is the one I have available.
Seriously I mean, I cannot review lenses and give recommendations. I can judge my lenses and describe their weak points. That might help you to make your own choice.
And then I take the freedom to define my "dream lens", which could exist, even though it does not (yet). Such "dream lens" also helps to benchmark existing lenses...
Dream lens
Focus length
The perfect focus length for my macro photography would be at least 100mm. 150mm or even 200mm would be even better.
In nature photography the subject distance even at a higher magnification is an important parameter.
F-Stop
It makes sense to have a fast lens, offering an f-stop of e.g. 2.8 (like what is available). At the same time the front diameter should be as small as possible to avoid shadowing the subject.
Magnification
The focus range does not need to be optimized up to infinity. It does not even need to offer infinity focus. It would be enough to have 1:10 or higher. The interesting macro world starts at 1:5.
However, my dream macro lens must support 2:1 or even better 3:1 natively.
A magnification of 1:1 is not sufficient!
The lens should be optimized between 1:10 and 3:1 (or 2:1 at least). The standard range of < 1:5 is not really interesting, since up to 1:1 is covered with so many existing lenses...
Picture quality
Of course I would expect the typical optimzation for the macro range, with excellent sharpness and contrast, moderate vignetting and distortiom and no CA.
I would expect no axial chromatic abberation and no longitudinal chromatic abberation - even at wide open aperture!
Especially when stacking photos, the longitudinal CA can cause serious issues in combination with light reflexes.
Autofocus
My macro dream lens must provide autofocus!
Many macro photographers consider the autofocus the least important thing for a macro lens - and for "standard" macro photography I would agree, since I would not suggest to use the autofocus to focus on macro subjects.
However, focus bracketing requires autofocus.
Cost
I would order immediately, if such a lens were available for Nikon Z-Mount, Nikon F-Moun, Sony E-Mount or Canon EF-Mount, even if it costs 3k€.
All the mentioned mounts can be hooked up to my Z6 properly (directly or with adapter) in such a way that the focus bracketing should work.
Laowa 100mm f2.8 2:1 Ultra Macro APO lens
This lens is the only one for full frame format, which offers a native magnification of 2:1.
Its optical perforfmance is really good, i.e. sharpness and contrast is very high even wide open. It shows no visible CA, even no logitudinal CA.
So it would be perfect for macro focus stacking, if it has autofocus.
Unfortunately the Laowa 100m/2.8 Macro does not offer neither autofocus nor aperture control from camera.
It still would be a good choice for stacking, if the manual focus had a wider range.
It is only a bit more than a quarter of a turn, which moves the focus from infinity to 2:1. That makes focusing difficult as such and stacking practically impossible. So stacking requires a macro rail.
This lens come with different mounts, here it is shown with Nikon Z-Mount. It is not water sealed, and the front is only "closed" with a simple filter (included).
What a shame: this lens, water sealed and equipped with autofocus would be perfect!
Laowa 25mm f2.8 2.5-5X Ultra Macro lens
A great lens for specialists, because it can only do macro between a magnification of 2.5x and 5x.
The focus length of 25mm sounds strange, and the subject distance is only a few cm (around 2 inch). However, the front diameter of the lens is small enough, which leaves enough light falling on the subject.
It does not only offer no autofocus, but no focusing adjustment at all.
It only offers a ring to adjust the magnification from minimum 2.5:1 up to 5:1.
It offers no electronics, i.e. supports no EXIF data) and no aperture control from the camera body.
It is optically superb, and the (optional) tripod clamp (as shown in the picture above) is not required, even though the lens is heavy and feels like "metal build", but it is small enough.
Focus stacking only works with a macro rail, ideally an automatic one, which offers a good resolution. Freehand shooting is possible but extremely difficult!
Nikon 200mm f4 D Micro Nikkor 1:1 (old)
Unfortunately this beautyful lens does not offer autofocus - at least not an electronic one (which is required to execute focus bracketing). So focus bracketing is not supported. The focus length of 200mm is quite nice for photography in the free nature.
Even the "manual focus bracketing", using the focus ring manually, I have never managed successfully.
The lens is heavy, but feels well balanced.
Extension tubes do not make a lot of sense at 200mm focus length, and even more the autofocus extension tubes for Nikon F-Mount introduce a heavy vignetting at close focus.
For focus stacking I cannot recommend this lens.
Sigma 105mm f2.8 D 1:1 (from ca. 2001)
This quite old lens is surprisingly sharp and good with very little CA.
Except the Laowa 100mm this is optically my best macro lens. Unfortunately it does not offer (electronic) autofocus, so stacking needs to be done manually.
So manual focus bracketing takes a little longer, but works very precisely with this lens. The lens is small and light-weight compared to modern versions of the same focus length.
This lens is not my overall first choice due to the missing focus bracketing feature, but is excellent otherwise. As long as subjects do not move, and you take your time, this lens is a lot fun to use.
Nikon AF-S VR Micro-Nikkor 105mm f2.8 IF-ED 1:1
This lens is not worth the money, I think. It is too expensive for the limited optical performance.
At the edges the sharpness is limited, and the very strong longitudinal CA makes it difficult to produce a clean focus stack.
The picture to the left shows the CA at wide open: The purple fringing in front of the focus and green behind the focus can clearly being seen.
I recognized those CA in a normal photo, and only then made the test. I only made a handful of photos before disappointed returning this lens.
VR (vibration reduction) is nice, but useless in macro photography to my experience, even if I shoot freehand.
Sigma 105 f2.8 EX-DG Macro-OS 1:1
This lens is the cheaper pendant to the previous one. It is sharper, but only a little better in terms of CA.
It is the best compromise, especially considering the much lower price.
Unfortunately the magnification is limited to 1:1 (which is true for the huge majority of macro lenses).
Since this lens is my only macro lense with electronic autofocus, it is currently my first choice, when doing a natur macro photo session.
Together with the Raynox 250 (close up lens) the magnification is almost 2:1 (considering the automatic crop due to the stack).
For normal macro the lens is sharp enough even wide open (effctive aperture = f5.6), so I do really use it wide open for a stack.
Together with the Raynox 250, I close the (indicated effective) aperture down to f10 or f11 to improve the contrast.
(Remark: that corresponds to a set aperture of f5.6.)
That closing of the aperture slows down the process of stacking, especially since for every exposure the aperture closes, and opens up afterwards. So the example above took 91 seconds. That makes 0.9 exposures per second, not an exciting value. However, the whole stack causes the aperture to close and open 168 times...
Remark: Sometimes the focus bracketing seems to "hang", when using extension tubes and starting at 1:1. The combination with Raynox does not hang at all.
Ansel Adams:
„Twelve significant stacks in any one year is a good crop.“
Sigma 300mm f4 APO Macro 1:3 (old)
A 300mm macro lens?
Yes, the old Sigma tele lenses were designed to support macro up to a magnification of 1:3.
That sounds not too much, but but with the 300mm it is attractive from wildlife photography. Many small subjects like small birds or dragon flies are good subjects for this lens.
It does not offer autofocus, so no focus bracketing. Its optical performance is much better than expected, but 300mm are large and heavy. With extension tubes the magnification can be slightly increased, but not much, and it becomes even more bulky for a macro lens.
So only for macro photography I would nor buy it, but if you can grab it somewhere by chance, it might be a bargain. Normally the price of this old and underrated lens is low.
Sigma lenses from that period do not have a good reputation and there are some (mainly the ones without "APO"), which are weak. But the Sigma 300mm/f4 APO Macro is worth it!
Nikon Medical-Nikkor 200mm f5.6 1:15 – 3:1 (age-old)
This lens is exoctic: it was designed in the 1960s and sold in the 60s and 70s. A successor with 120mm focus length as build later.
This lens was used - as the name already suggests - in the medical area. Dentists used it often.
It is a pure macro lense with adjustable magnification, using different small lenses, which need to be screwed to the front.
The highest magnification is 3:1, there is no focusing and no electronic connection to the camera body - except the flash light cable.
The lens contains a build-in ring flash. On the picture on the left, you can see the power cable hanging down). The flash is driven by a large battery box, which requires 8(!) batteries of the size D (not shown on the picture).
The trigger cable for the flash fit into the D700, but not anymore into the Z6.
Amazing: with the D700 the lens including the flash works without any problems.
The optical performance does not satisfy electronic sensors to be honest. This lens was innovativ, when it came out, but more for a museum nowadays. It is understandable if todays manufacturers do not design and build such exotic lens anymore. It is sad though, too.
Raynox M-250 close-up lens
This close-up lens extends the magnification of standard lenses or macro lenses.
I have disdained this lens for a long time, but use it quite often in the mean time.
It is the only way for me to use focus bracketing at a magnification > 1:1.
There are a few of these lenses available, but this Raynox 250 offers the best price / performance ratio in combination with a "normal" 100mm 1:1 macro lens. It is available with a snap adapter, which fits in front of the most macro lenses.
Microskope lenses
There are a few excellent microscope lenses available, partly even ready to be used with a camera. I can recommend the Traumflieger-Shop form more details.
My largest magnification was 14:1, which already requires a steady and stable setup - and an automatic macro rail. A standard tripod normally is not good enough, and a manual rail does not provide enough resolution and accuracy.
However, I am concentrating on macro in the range around 1:1, maybe up to 3:1. Especially in free nature this is by far challenging enough. Therefor the magnification in that range is not part of this "workshop".
Summary
For the Z series, more than 2 years after introducing the Z-Mount, Nikon has not even a single macro lens available in their portfolio. Either you use third party products or you use the F-Mount lenses with the FTZ adapter.
This indicates the (missing) significance of macro photography at a manufacturer like Nikon. It might indicate the overall difficult situation of the camera market as such.
Even manufacturers like former Olympus, who focus a lot more on macro photography, do not have a macro lens in their portfolio, which covers a magnification of >1:1.
(However, to be fair, the MFT already gains the factor 2 due to the sensor size...)
So I hope that in the near future one manufacturer closes this gap, and - instead of releasing the 99th bad standard macro lens - develops a reasonable high quality macro lens, which covers my requirements (see above).
Laowa seems to be the most promising candidate - if they manage to come up with electronic control.
