The 'fun' aspect of the Laowa Probe 24mm f/14 is undeniable. However, the sibling Laowa 25mm f/2.8 Ultra-Macro 2.5-5X is a true workhorse if you are into studio photomacrography. The range 2.5 to 5X life-size is very useful for many natural subjects and I have used the lens very extensively for the last 5-6 years, in conjunction with my Aquatic Plant Project.
The lens is quite small, but extends significantly when the magnification is increased. There is no focusing as such, only a collar to change magnification. The lens is *not* parfocal across its magnification range thus needs to be carefully focused for a given shoot, preferable mounted on a sturdy focusing rail or suchlike setup. Getting the required depth of field at these magnifications is futile just by stopping down the lens, thus focus stacking is the obvious approach and the one used exclusively in my work with the 25 Laowa. At the short end of focusing, f/4 delivers excellent sharpness, whilst at 5X it is preferred to set the aperture to f/2.8. The sharpness is quite good to excellent and despite the lack of ED elements, chromatic nasties are rarely an issue. However, for motifs that are partly submersed such I often encounter, the refractive properties of the air-water surface will introduced some visible colour fringing. Judicious placement of the light source(s) can mitigate the CA to some extent, though, but retouching may be required later. One cannot really blame this on the lens as it is the physical nature of the subject, rather than the optical properties of the lens, that bring forth the chromatic issues. Any lens in the same situation will encounter a similar problem.
So far, so good. Below is the setup I use with the Laowa 25 mm f/2.8 lens. There is a (cheap) cute LED ring light that can be added to the front of the lens and powered by USB (PC or powerbank). However, due to the danger of added reflection in the water interface, I rarely use the ring light.
As shown, the camera + lens is at an angle to the subject. More often I use the setup in a vertical orientation, many times with the fibre optic cables proving backlighting to the subject. Working distance is several cm and the narrow snout of the lens makes lighting the subject easy.