Іван Циба wrote: > Sorry for maybe stupid question, but I don't understand why UV filter is > needed in some cases in reflective media spectro measurement. > When you measure fluorescent paper with UV cut instrument, results will be > only acceptable in non-UV lighting conditions during viewing of that paper? Correct. Some people seem to be under the illusion that a UV filter magically makes FWA/OBE problems go away though. Graeme Gill.