Heh, that didn't occur to me to check
According to the plot there, the peak is 370, that may be achievable with normal cameras just with filters - on a bright day.
edit: i found some information on DSLRs and UV -
Canon DSLR EOS camera’s and Ultraviolet (UV) photography « Mickyj's Mindspillage - it's old, but the situation is probably same or worse. Seems to dramatically prefer old (CCD-based) Nikkons, there are even dedicated lenses. Canons have to be modified, but all CMOS stuff is disadvantaged. Overall seems like a rather difficult job. Maybe I should borrow a CCD camera at work, rig a power source and RPI on it for field use and get a filter and try
edit2: really nice filter discussion here -
Infrared block, broad UV and visible pass filter? - also explains that wjild filters with maximum at 355 are easily available, you'll be getting 380 images due to multiplication of sensitivity and solar radiation curves. Still apparently pretty interesting. I am now pretty convinced to try this with astronomical CCD cameras and see where it goes, will make a more appropriate thread if I get results.
edit3: I know this is quite off-topic, but I have even found a workable filter - the Johnson U filter used in astronomy is basically perfect, the ones that we have have a maximum a 360 and cut at 390, with no IR leak at least until 1200. Those are completely useless for us, but for some reason, we have sets of filters that include them. Tomorrow at work I'll try to find all the pieces and maybe I'll be able to start imaging birds