EOTech Vudu Scope And The Advancement Of Precision Glass

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Top-shelf optics have come a long way in a short time as demonstrated by the EOTech Vudu scope.

What Are The Major Scope Advancements:

• Lens glass is more uniform with greater clarity.
• Automated grinding and polishing create a more consistent product.
• Advancements in lens coatings allow for more light transmission than ever before.
• Less variability in rings and bases provide a stable mounting platform.

When I was first learning to shoot, the glass you could buy for your rifles (there were no real handgun or shotgun optics back in the Neolithic era) came in three grades: miserable, tolerable and pretty darned good. By the time I was working in gun shops, the grade of the glass had move up. You could by then choose from OK, very nice and dayum.

Today, the world is awash in good optics, and good glass is part of that. I had a chance to realize this when I looked at an EOTech Vudu scope, and I had to re-name the grades of glass again.

Today, we have very-very nice, dayum and “you’ve got to be kidding me” — from now on known as “YGTBKM.”

I recently pulled a rifle out of the rack, one that had a riflescope on it that fell into the “very nice” category of the earlier era. I checked to make sure the rifle wasn’t loaded, and I looked through the scope. Was there dust on the lens? No, it just was a very nice scope from the 1980s. The EOTech Vudu, which falls into the “dayum” category, made the 1980s scope look as if it needed some significant service work done.

Seeing The Light

How has this happened? Well, lens makers have taken advantage of chemical and testing advances to produce the base glass product used in lenses. There are much fewer impurities than in the old days, and the uniformity of the glass — both within a lens and from one lens to the next — is much greater.

Optics are now calculated, and lenses designed by computer. Not that computers know anything about optics other than what we tell them, but they can make changes and predict results right now, not next week.

In the old days, it was still slide rules and desktop calculators, with the finalists in designs getting the serious mainframe computer time. Your smartphone has more computing power than the mainframes used for the 1980s optics.

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Then there is the grinding and polishing. This is automated, and it’s done by machines of utmost precision. My youngest brother used to work for various companies that made and installed multi-axis machining stations. They did aerospace-level work, and the machines were so big, and they required such a stable platform, that they didn’t have foundations — they had piers.

When his company installed a machine, they bolted it not to a concrete slab with footings, but to a 10-foot cube of concrete cast into the surface of the planet. Lacking that concrete block or something even larger, the company refused to guarantee the “tenth” the machines could deliver: a ten-thousandth of an inch precision or less.

The precision of the automated machines that now grind and polish lenses make my brother’s old company’s machines look like wood rasps stapled to a belt sander. Grinding precision is not measured in tenths, but in microns. Or, it can.

Then there are the coatings.

When light strikes a glass surface (any surface of a clear substance, really), most penetrates and is refracted, but some is reflected. In a counter-intuitive result, a particular chemical coating on the surface of the glass can reduce the amount of reflection. A coating is only effective for a small section of the light spectrum, so lens makers will multi-coat their lenses. This reduces reflection in a wider array of frequencies. This coating is the color you see on the front lens of your scope. Those coatings are also applied in a thinner and more uniform layer than ever.

By reducing reflection, scope makers increase the percentage of light that passes through to your eye.

OK, so let’s add it up: We have better-quality glass. We have more-precisely calculated, ground and polished lenses. We have coatings for the important parts of the spectrum, and those coatings are pure, uniform and consistent.
And all of that is mounted inside of tubes that are more uniformly machined that in the old days, with more robust adjustments, and in more solid mounts.

Oh yes, the mounts.

The Mounts Do Matter

Back in the old days, we took two paths: We either used inexpensive mounts, and we mounted an inexpensive scope in them for no-big-deal applications. A $79 scope would be bolted onto a rifle with $20 bases and rings, and that was more than good enough for deer hunting. If you wanted more, you used all-steel rings and bases, hand-fitted to the rifle, and the rings were hand-lapped for uniformity.

And you’d put a “very nice” scope in that, because anything less wasn’t worth the effort.

Today? These days the scope mount manufacturers use the same multi-axis machining technology that everyone else does to produce rings and bases of startling uniformity.

As an exemplar, the Geissele mount, with an EOTech Vudu 5-25x riflescope.

Geissele machines the rings into the mount, and then marks the ring tops: You have not just front and back rings to the mount, but they are marked so you can keep them oriented correctly. If you go and try to lap the rings for a better fit, you reduce the precision. The Vudu is made with the best cost-effective glass to be had. Oh, there is better glass, but when you go up to the YGTBKM category, you aren’t just buying a scope, you are plunking down 5+ house payments just for optics. But if that’s what you want, then do it.

For the more traditional rifle shooters, simply walk to the next aisle and select from the Warne rings and bases.

We do this because we can get all this precision — this fantastic quality — for less money than the “OK” or “very nice” optics cost us back then. The MSRP on the Vudu is $2,100. The Geissele mount, $325. OK, almost $2,500 is not inexpensive. But, you can easily spend twice that for the YGTBKM scope alone.

So, let’s run the inflation calculator in reverse mode. When I began working in gun shops, the equivalent cost would have been $600. I can tell you that the scope and ring/mount setup you could have bought in 1978 for $600 would pale in comparison to the Vudu and Geissele combo.

Going back a few years before then and stealing a song lyric: these are the good old days. It’s true … at least as far as optical quality is concerned.

Editor's Note: This article originally appeared in the February 2019 issue of Gun Digest the Magazine.