UV photography is quite a bit more challenging than Infrared on converted digital cameras.
Dr Klaus Schmitt's website
Photography of the Invisible World is an excellent place to start
All the older style UV pass filters leak near IR (U330, U340, U360, UG11, ZWB2 etc) - this wasn't a problem with film which didn't see IR but our Full spectrum cameras are more sensitive to NIR than UV. There are some filters that have been coated to block this leakage (Baader make one) but the price is well outside my budget. A partial solution can be achieved by stacking a IR blocking filter such as BG38, BG39 & BG40 but these reduce the UV portion significantly.
Lenses are another sticking point, glass absorbs UV & many modern lenses are coated specifically to block UV. There are special quartz lenses made for UV photography - but I've never seen any for under £1000, and those that are around are rarely sold. Fortunately some affordable lenses aren't too bad. The 80mm El-Nikkor enlarging lens I brought (recommended by Klaus on the website above) transmits 54% of UV at 350nm the best of any of my photographic lenses. With other lenses fast lenses are typically particularly poor due to the larger amounts of glass present.
UV torches are generally not very power sources (sunlight is better) but you can adapt a flash gun to remove the UV blocking filter & provide a fairly powerful UV source (protective goggles are recommended if tacking this approach).
So far my efforts have never amounted to more than a vague proof of concept with some UV features barely visible - It's high time I had another go! Getting images of UV induced fluorescence has proved much easier, just needing a UV source & visual darkness with normal cameras...
One thing I've been meaning to try is using a single element quartz lens. This will not be corrected for the many aberrations, but hopefully the range of wavelengths being studied will be small enough that chromatic aberration isn't a problem & most of the rest are dealt with by using smaller apertures. I have a LONG list of things to try!