Canon EF-M 18-55mm f/3.5-5.6 IS STM

SLRgear Review
March 4, 2013
by Andrew Alexander

Canon announced its EOS-M mirrorless camera in July of 2012, and the EF-M 18-55mm ƒ/3.5-5.6 IS STM was one of two lenses to be released with it.

The 18-55mm ƒ/3.5-5.6 IS STM was designed specifically for the EF-M lens mount, and is incompatible with other Canon bodies. The EF-M mount is designed around an APS-C sensor: in 35mm film terms, the effective field of view is approximately 29-88mm. Be sure to check out our review of the EOS-M at Imaging Resource.

The lens does not ship with the EW-54 lens hood - this is an optional accessory that retails for around $30. We had a little trouble tracking it down, and found it can be purchased from Adorama here. The lens itself takes 52mm filters and is available now for around $300, or as part of a EOS-M camera kit.

Sharpness
The Canon EF-M 18-55mm ƒ/3.5-5.6 IS STM provided surprisingly sharp results. When used wide open at ƒ/3.5, there is some slight corner softness, but the majority of the frame is very sharp. Stopping down to just ƒ/4 (or after 24mm, ƒ/5.6) provides very sharp images - for practical purposes, we would say it's tack-sharp from corner to corner. According to the raw numbers you'll have to stop down to ƒ/8 or ƒ/11 at 55mm to see the sharpest results, but to the naked eye I doubt you would see the difference.

If there's a weak point for this lens it is the 55mm focal range setting, where sharpness isn't quite as impressive as the other settings: that is to say that between 18-45mm, the lens can be stopped down 1-2 stops to get an improvement in sharpness. At 55mm there's an upper limit to the improvement that's obtained, which is still quite decent, just not as good as the other focal lengths.

The lens is sharp all the way to ƒ/8, where diffraction limiting begins to set in, but there isn't a significant impact on sharpness until ƒ/11, and even then it's just a slightly overall decrease. Images start to lose their sharpness at ƒ/16, and become quite soft at the smallest apertures across the focal range (ƒ/22-36).

Chromatic Aberration
The Canon EF-M 18-55mm ƒ/3.5-5.6 provides acceptable performance between 24mm and 45mm, but we note some obvious chromatic aberration present in the extreme corners of the frame at the wide and tele settings (18mm and 55mm - take a look at our sample images for further detail). It's most noticeable at the 18mm setting, showing up as magenta-cyan fringing in areas of high contrast. In the center of the frame, it's not an issue. Stopped down to ƒ/8, it's less prominent but still visible in the corners: again, the center of the frame is fine.

Shading (''Vignetting'')
There is some slight corner shading with the 18-55mm ƒ/3.5-5.6 IS STM: used at the ƒ/3.5 (at 18mm) setting, the corners show up around a half-stop stop darker than the center of the frame. This is alleviated as the lens is stopped down, and at focal lengths of 35mm or greater, there's no corner shading of significance at all. It's worth noting that our still life shots (found in the sample images) are done with default settings, which means that the Peripheral Illumination is enabled, so you can see how the camera can correct for corner shading.

Distortion
Zoom lenses usually have to contend with distorted results, and the EF-M 18-55mm has its share of issues. Distortion is manageable, but noticeable - at the wide end, there is a full 1% of barrel distortion in the corners, and 0.5% throughout the image. As the lens is zoomed in this distortion is alleviated until it reaches a zero point at the 28mm mark. Zooming further towards 55mm, we begin to note pincushion distortion in the corners, at its worst at the 55mm point, where we see 0.4%.

Autofocus Operation
Canon employs a STM motor on this lens, providing near silent operation. Unfortunately it's not especially speedy, taking well over a second to go through its range of focus.

Macro
The lens, while not specifically built for macro, offers some usable close-up capability. Maximum magnification is 0.25x, with a minimum close-focusing distance of around four inches.

Build Quality and Handling
The EF-M 18-55mm ƒ/3.5-5.6 IS STM lens is small and light (210 grams, 7.4 oz): it comes finished in a dark gray color. The lens may be small, but it's not small enough to let you put this lens and camera combination in a large coat pocket; however, you could carry the two separately for attachment in the field.

The lens has eleven elements in thirteen groups, with three aspherical elements, and has a rounded aperture with seven blades. There are no switches or control surfaces other than the manual focusing ring, so its simple design matches nicely with the EOS-M.

The focusing ring is a scant 1/8'' in width, plastic with a cross-hatched pattern for texture. The focusing design is electrical, so the ring will turn in either direction without stopping. There is a no lens extension as the lens is focused. The front element (and any attached 52mm filters) will not rotate during focusing operations.

The zoom ring is a bit larger at 5/8'' in width, also plastic with a cross-hatched pattern for texture. The zoom rignt takes about 75 degrees of turning to go through its range of focal lengths. There is about one inch of lens extension as the lens is zoomed in to 55mm. The zoom action is nicely cammed and takes only about two fingers of pressure to move. There is no zoom lock switch, but we doubt a lens of this size will need one.

The EF-M 18-55mm is equipped with Image Stabilization, which works quite well for this lens. See our IS Test tab for more details.

The optional EW-54 lens hood is available for the lens, but does not look to provide a huge amount of shade for the lens.

Alternatives
There aren't a lot of alternatives at the time of writing, owing to the young age of the EF-M mount.

Canon EF-M 22mm ƒ/2 STM ~$250
The 22mm prime is slightly sharper overall than the 18-55mm, and provides slightly better performance for CA and vignetting; there's also zero distortion.

Conclusion
For a small and relatively inexpensive lens, the Canon EF-M 18-55mm ƒ/3.5-5.6 IS STM provides very good results, typically of kit zoom lenses.

Product Photos

Sample Photos

The VFA target should give you a good idea of sharpness in the center and corners, as well as some idea of the extent of barrel or pincushion distortion and chromatic aberration, while the Still Life subject may help in judging contrast and color. We shoot both images using the default JPEG settings and manual white balance of our test bodies, so the images should be quite consistent from lens to lens.

Still Life shot

VFA target

As appropriate, we shoot these with both full-frame and sub-frame bodies, at a range of focal lengths, and at both maximum aperture and ƒ/8. For the ''VFA'' target (the viewfinder accuracy target from Imaging Resource), we also provide sample crops from the center and upper-left corner of each shot, so you can quickly get a sense of relative sharpness, without having to download and inspect the full-res images. To avoid space limitations with the layout of our review pages, indexes to the test shots launch in separate windows.