The 11-22mm bears more than a passing resemblance to Canon's EF-M 18-55mm kit zoom, and shares all of the same design cues. So the entire 'skin' of the barrel is made of metal, including the zoom and focus rings which have finely-patterned grips. The mount is metal, and the extending portion of the barrel is plastic. Both zoom and focus rings operate satisfyingly smoothly - the overall impression is of a nicely-made product.
The lens uses a similar retraction mechanism to that pioneered by Olympus on its original Micro Four Thirds kit zoom, and now used by several other manufacturers including Samsung and Nikon. To extend the lens from its collapsed position, you simply rotate the zoom ring to the 11mm mark or beyond, and shoot away as normal. At this point a catch mechanism comes into play that prevents you from inadvertently rotating the zoom ring back past 11mm. To retract the lens, you first have to push forward the sprung lock switch on the side of the barrel.
In the view above we've shown the lens in its collapsed and longest 'operational' positions (at 11mm). The barrel retracts slightly in the middle of the zoom range before extending again at 22mm, which means that the length saving in the collapsed position is about 13mm. This isn't quite as impressive as some other lenses, but worthwhile nonetheless.
On the camera
The 11-22mm balances nicely on the EOS M, and operates almost identically to the 18-55mm kit zoom. The wide zoom ring falls nicely to hand, and when the lens is retracted, the overall package is impressively compact. In fact it's probably the smallest available option for pairing a wideangle zoom with an APS-C sensor (although the Micro Four Thirds Olympus PEN E-PM2 and M.Zuiko Digital ED 9-18mm 1:4-5.6 is smaller still).
With its existing firmware the EOS M can't recognise when the lens is in its retracted position, and will allow the shutter to release. Canon recommends updating the firmware to the co-announced Version 2.0.0 for full compatibility, which as a bonus promises faster autofocus with all lenses.
Size and design compared to existing Canon EF-M lenses
Here's the 11-22mm sitting in between the EF-M 18-55mm f/3.5-.6 IS STM kit zoom and the EF-M 22mm f/2 STM pancake. The family resemblance is immediately obvious - in fact owners of both zooms may well struggle to tell them apart at a quick glance. The main visual differences are the 11-18mm's wider zoom ring and lock switch.
Size compared to other wideangle zooms
There's the 11-22mm nestling between Canon's EF-S 10-22mm f/3.5-4.5 USM for APS-C SLRs, and the Olympus M.Zuiko Digital ED 9-18mm 1:4-5.6, which is one of the smallest wideangle zooms currently on the market (the Nikon 1 Nikkor VR 6.7-13mm f/3.5-5.6 is even smaller). The 11-22mm has neither the range nor the brightness of its EF-S stablemate, but it's clearly a lot smaller (and barely more than half the weight). It may not be quite as tiny as the Olympus lens, but it covers a larger sensor, and packs in optical image stabilisation too.
Compared to EF-S 10-22mm f/3.5-4.5 USM - on the camera
One of the biggest advantages afforded by mirrorless systems is that not only can the cameras be made smaller, but lenses often can too, with the biggest advantages generally gained with wide zooms. Here's the EF-M 11-22mm on the EOS-M compared to the EF-S 10-22mm on Canon's smallest SLR, the diminutive EOS 100D (Rebel SL1). The 11-22mm may not offer quite as wide a view, but it does include image stabilisation. Of course mirrorless systems come with a other compromises (and advantages) too.
Here we're comparing the EOS M fitted with the EF-M 11-22mm, to the EF-S 10-22mm on the Mount Adapter EF-EOS M. Here the 11-22mm is less than half the weight, and little over half the length; not surprisingly it also autofocuses much better.
The 11-22mm uses a very similar AF system to the 18-55mm kit zoom, and our initial impression using an EOS M running Firmware 1.0.6 is that the autofocus speed is very similar too. That is to say, it's acceptable for many purposes but not breathtakingly quick, especially in comparison to the extremely high bar set by Olympus and Panasonic in particular. Of course the really big unknown is how much of an improvement Canon delivers with Firmware 2.0.0.
Lens body elements
The EF-M 11-22mm f/4-5.6 IS STM is Canon's third lens for its mirrorless EOS M camera, and adds a useful wideangle capability in a package that's impressively compact - especially considering that it's got optical image stabilisation too. Our initial feeling is that it's a rather nice little lens that's pretty well-built, and a good match for the EOS M. It could well offer an interesting alternative for landscape or travel photographers who want a wide zoom, but wish to reduce the weight of the kit they're carrying.
Arguably the bigger question, though, is whether Firmware 2.0.0 will improve the EOS M's focusing performance to make it a more credible contender in this market. Because, however good the 11-22mm turns out to be, at the moment it only works on a single camera that's just a little underwhelming compared its peers - especially in terms of autofocus performance. If Canon really wants to compete seriously in this increasingly popular segment, it'll surely have to get up to speed sooner rather than later.