This is a test shot to illustrate the actual difference between a very expensive lens ($5000 +) and another, very cheap one which I paid less than $30 for. Captures are 100% crops from the peripheral parts of the frame, where the performance differs the most.
UV done with my modified Z6 and the Baader U filter. Illumination by 2*800 Ws studio flash and exposure is the same in both cases, thus the UV response level-wise is about equal. Alas this was to be the only comparison shot as one of my flashes literally exploded soon thereafter with a bang that made me deaf for hours. All fuses blew of course. It must be the condenser that failed. Until the studio flash is repaired I have to postpone other testing, or wait until I can break my C-19 quarantine and seek the big outdoors.
It is easy to see the difference here, but do keep in mind the enormous price difference and the fact that also the cheap lens was almost
parfocal visible to UV, which is a feature very rarely observed apart from the expensive specialist UV lenses. In case one wonders, yes the infamous UV striping of the Z6 is present as I did not run the NEFs either through a dedicated plugin (Topaz) or a raw converter capable of dealing with the issue (RawTherapee). This was done in Photo Ninja.
I keep the lens identities under wraps for now. Suffice it to say I paid more for the dedicated adapter for it to Z6 mount than for the lens itself