Cartridge setup experts: Azimuth critique

@ketchup  IMO you're way ahead of many of the posters here. First, you recognize that lighting is a factor, and that it's tricky. Second, you realize that perpendicularity is a matter of degree in the real world. Third, you know enough to ask for advice. Fourth, you know your tonearm and how repeatable the adjustments are, and how hard it's going to be to improve on what you have.

I say, play something. If the channels sound more or less equal, that is volume and distortion, leave it alone.

Just my opinion.

Perhaps it is indeed a placebo effect, but, when I use adjust + to set the azimuth I am consistently impressed by the more lifelike imaging.  I also notice that very small adjustments on my Kuzma arm result in better electrical results.  No way I would be able to visualize these differences with my USB microscope.  The stylus looks good both at reference levels parallel to the surface (love the Wally Reference Tool) and at the final Adjust + optimal settings. 

These are not night and day differences but its enough to motivate the effort. And much more of a pain in the butt with a Jelco style headshell.

You are right on, @karl_desch - tiny changes to azimuth are easily measurable and audible. Of SRA, VTA (different things and important for different reasons, actually!), zenith correction and azimuth, the azimuth angle is most sensitive to angular changes. This is not only borne out subjectively, but there is a mechanical reason to it as well.

If more people understood the purpose of the stylus’ major radius, perhaps they’d be less intent on visually aligning the azimuth angle and pay attention to what really matters - an orthogonal relationship between the 45 degree groove wall and the coils (discounting any left/right variation in the magnetic flux field, of course).

Below is a link to an image of a PROPERLY aligned cartridge on the azimuth axis. 2.6 degree tilt! While this is the product of less than attentive assembly, it is certainly where this cartridge performs its best. Its ~50um major radius allows for this kind of angle without causing one contact edge of the stylus to meet the record land/groove junction. Both contact edges remain properly seated in the groove.

You can't optimally  align a cartridge visually. You can get it close but you will never get it right... you need tools. The Wally way is one approach.

I use Analog Magik. Can't believe I went all these years without it. 

bottom line, visually may be a starting point, but it is never an end point