The Canon EF-M 28mm f/3.5 Macro IS STM fills a macro-sized hole in the range of native mount lenses for Canon’s APS-C format EOS M system cameras. With an effective focal length of 45mm in full-frame terms, it also works well as a ‘standard prime’ for general shooting, while also delivering full 1.0x macro magnification for extreme close-ups, boosted to 1.2x in Super Macro mode.
Mount: Canon EF-M
Lens construction: 11 elements in 10 groups
Angle of view: 52 degrees
Diaphragm blades: 7
Minimum aperture: f/22
Minimum focusing distance: 0.093m
Maximum magnification ratio: 1.2x
Filter size: 43mm
Although small, the lens packs in a lot of useful features. STM autofocus is highly effective for both stills and video capture, and there’s a hybrid image stabilizer which corrects for x-y shift as well as the more usual angular vibrations. Stabilization is highly effective in general shooting but less so for close-ups, and no real substitute for a tripod in full macro shooting. Speaking of which, the lens features an additional Super Macro mode, which boosts the maximum magnification from 1.0x to 1.2x.
The working distance at maximum magnification is just 13mm between the front of the lens and the subject. The forward end of the barrel is chamfered to reduce shadows but the lens can still block out ambient light. It therefore features a built-in LED Macro Lite, for which you can select one side or the other, or use both sides simultaneously, along with two selectable brightness levels.
The incredibly close working distance can make full macro shooting quite tricky but the LED Macro Lite comes in useful. In our tests, it enabled exposure levels equivalent to 1/15th of a second at f/8 (ISO 200). That’s a stop faster than Canon’s similar EF-S 35mm f/2.8 Macro IS STM that’s designed for APS-C format EOS DSLRs. Sharpness is pretty good and there’s not too much in the way of color fringing or distortion, which can be automatically corrected in-camera.
We run a range of lab tests under controlled conditions, using the Imatest Master testing suite. Photos of test charts are taken across the range of apertures and zooms (where available), then analyzed for sharpness, distortion and chromatic aberrations.
We use Imatest SFR (spatial frequency response) charts and analysis software to plot lens resolution at the center of the image frame, corners and mid-point distances, across the range of aperture settings and, with zoom lenses, at four different focal lengths. The tests also measure distortion and color fringing (chromatic aberration).
As with most Canon EF-M lenses, sharpness is good rather than entirely great. A little disappointingly for macro shooting, sharpness drops off quite noticeable at very narrow apertures, often favored for gaining a little extra depth of field when shooting extreme close-ups.
Color fringing is very minimal, even towards the extreme edges and corners of the frame, and can be effectively eliminated with in-camera correction.
There’s just a touch of pincushion distortion but, as with lateral chromatic aberration, in-camera correction is available in current EOS M system cameras.
This is Canon’s one and only dedicated EF-M macro lens for EOS M cameras, and it has a surprisingly short focal length, equivalent to shooting with a 45mm lens on a full-frame camera. Typical of EF-M lenses, it’s wonderfully compact and lightweight, tipping the scales at just 130g and featuring a retractable design to reduce stowage size. Even so, it gives a mighty 1.2x macro magnification factor and has a built-in LED light to illuminate the subject.