Originally Posted by RobertP
The major difference is the light source itself. The V-28 uses a metal halide lamp, the ULF-28 a Continuous Wave Xenon. The advantage of the latter is immediae re-strike capability, very useful if you need to make multiple exposures in a short perod of time. With metal halide lamps you must allow the bulb to cool for a period of time before they will strike again.