The modern Copal 3 is a perfect match for both my meters-gossen luna -pro,gossen ultra spot. the#5 Ilex has a different scale that only crosses over at 2,the same as all other IX shutters I have seen. The question is this Are the shutters the same having simply selected different stops? Is 4 on the meter one notch under 5 on the shutter and 8 midway between 5 and 10? Have not had a chance to mount the IX yet ,it is going of for a CLA first.