Actually that lens design was developed and used long time as their (former GDR) best wide angle lens, used for their "Reihenmesskammer" for aerial reconnaissance. This lens here is a derivative of its larger brother, with an reduced image angle and most likely a symmetrical 8e/4g design.
Here is a technical article of my friend Marco Cavina, that covers such ultra wide angles nicely with lots of images and diagrams as well as showing never finished prototypes.
[click on image to see a larger one]
UV-VIS differential:
![](http://www.pbase.com/kds315/image/139209978/medium.jpg)
Focus shift? Very small and neglectable!
VIS:
![](http://www.pbase.com/kds315/image/139210057/medium.jpg)
UV:
![](http://www.pbase.com/kds315/image/139210058/medium.jpg)
Closeups:
VIS:
![](http://www.pbase.com/kds315/image/139210245/medium.jpg)
UV:
![](http://www.pbase.com/kds315/image/139210246/medium.jpg)
IR:
![](http://www.pbase.com/kds315/image/139210380/medium.jpg)
well, no complaints I would say..
[unfortunately also that flower has already started its decline, which UV shots reveal so easily...]
Stay tuned, more will follow on that fascinating subject...
More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos