One problem is the light intensity range, another is the ammount of UV generated, I would make a filter using welding filter glass, the shade depending on the current, you might try shooting in segments, first with a dead stick and no filters to show setup position, then use a couple of flood lamps and the filter to show the strike and pulling the arc, running the bead and puddle. Using the welding filter will remove any UV problems from overloading the CCD, I would also use manual settings on the iris control and change as necessary, you can try a lower number filter if too dark, conversely a higher number if too bright and out of the cams ND and iris adjustment, using a gold coated filter may help.