[click on image to see a larger one]
Visual shot:

Simulated bee vison using XBV3 filter:

Simulated bee vison using XBV2 filter:

Simulated bee vison using XBV5 filter:

UV using Baader-U filter:

UV using Jupiter-U filter:

The idea behind that 2nd set was to get a better estimate of the VIS-UV focus shift (measured 5.8%, VIS is quite larger) as well as to show the effect of out-of-center imaging, to get an idea how the blur develops. I guess that gets pretty clear now.
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