The team over at LensRentals has posted a teardown of the Canon EF 70-300mm f/4-5.6 IS II USM lens.
From the LensRentals Blog:
As with most new lenses, a Canon 70-300mm f/4-5.6 IS II made it’s way back to the repair department for an initial tear-down. I know there’s some randomness as to what we tear down, but we have some reasons for doing these. Sometimes, like with this new Canon, it’s simply because we know Lensrentals is going to stock a lot of them and we need to take a look inside to see what is likely to break and what parts we may want to order. And other times, like with this new Canon, it’s because there’s some new technology inside we want to take a look at.See the entire article on the LensRentals Blog.
And, of course, almost all the time these days, there’s some aphasic marketing terminology that leaves Aaron and I looking at each other wondering “what are they trying to say that is.” This time it was “NANO USM technology.” Did that mean there were little nanobots in there focusing the motors? Or that the focus group only had to move nanometers? The problem seemed to have been compounded because some retail and review sites were claiming it had a stepper motor, a ring USM, or both. That’s what happens, marketing department, when you make up words, nobody understands without explaining what you mean.
Looking inside seemed a good way to clarify that. Though Canon did tell what they meant a little bit, but nobody read it. The NANO USM focusing motor made its debut in the Canon 18-135 f/3.5–5.6 IS NANO USM lens last year, but not many people talked about it. It’s also discussed in Canon’s Knowledge Base NANO USM Article, but not many people read that. The NANO USM motor is a different focusing system for Canon, although manufacturers have used similar linear piezo systems.
And, as always, we wanted to see what engineering goodness Canon had inside that polycarbonate lens shell. We’re geeks. Sweet design pushes our buttons, and Canon lenses have had a lot of sweet engineering lately. Even though this is a consumer price range lens, the new digital focusing meter was cool, and we wanted to see if some of the impressive engineering Canon had put in their new L series lenses was drifting down to the consumer grade models.
So let’s tear up, I mean let’s carefully dissect, the new Canon 70-300mm IS. But first, let’s take a quick look at that nice digital readout. I can’t say it’s all that useful, but the depth-of-field-by-aperture display is a nice touch.