It toook me some time to get the hang of it. Lots of eye-strain. As Yip advices, patience and rest are very important as well as excellent lighting. I set my turntable on a desk right next to a window with bright northern light. My revelation came when I realized that to get the cantilever parallel to and between the lines at the two null points, it was a matter of rotating the cartridge in the headshell ie. zenith or off-set angle and NOT azimuth. After I figured this out, everything lined up perfectly with a degree of precision that is incredible. The improvement in sound - details, air, and bass definition - were well worth the $110 and set-up frustrations. It is a wonderful tool and definately the best bang for the buck I have ever spent on my system. Very highly recommended.
Peter
Peter