What Is Nano USM And Why Should It Matter When Choosing A Zoom Lens?

Canon’s engineers came up with a way to make lenses lighter and more precise, literally by making its components much smaller, and functionally too, because you now only need one zoom lens for both stills and video. Here’s how the magic works.

- Zachary Chan

WHAT’S IN A NAME?

We’re normally more caught up in the advances made to a camera body than the lenses that accompany it, and rightly so, because that’s where all the megapixels, varied autofocuses, and image processors are all located after all. What about lenses then? Are they just the sum of their focal lengths and aperture ratings?

Take Canon’s standard EF-S 18-135mm zoom lens for example. There have been multiple versions of this lens, the EF-S 18-135mm f3.5-5.6 IS from 2009, the EF-S 18-135mm f3.5-5.6 IS STM released in 2012, and the EF-S 18-135mm f3.5-5.6 IS USM released in 2016. You’ll notice that all three lenses have exactly the same optical specifications; 18-135mm telephoto length and f3.5-5.6 aperture. All three lenses have image stabilization, as indicated by the IS designation.