I do not believe the amount of light that lenses and tube size allows through, has anything to do with the amount of adjustment that is available. Different lenses allow different amounts of light through. Same as the coatings. One of the reasons Leupold calls their 30mm LR(Long Range)is due to the fact that is has more elevation adjustment than a standard 1 inch scope. But this adjustment has nothing to do with the quality of lenses, and amount of light transmission. IMO, Tom.