Canon EF-M 22mm f2 STM user lens review 26 July 2020

Canon introduced the first EOS-M camera in 2012 with two initial lens offerings. These were the 18-55mm kit zoom (since replaced by the 15-45mm) and the 22mm f2 STM compact prime which is the subject of this user review.

The 22 f2 has remained a firm favourite with M users and is often cited as one of the sharpest lenses available for the EF-M mount.

The 22mm focal length is equivalent to 35mm on a full frame camera.

Basically anybody who owns a Canon EOS-M series body and who wants a high quality compact prime lens. The thing is so small it will fit in to any small space in a camera bag or pocket (wrapped in a plastic sleeve please to prevent dust entry) and so inexpensive I can think of no compelling reason not to buy one.

General photography, street, documentary, family and indoor/low light work, landscapes and city scenes.

The focal length makes it very versatile and suited to many photographic challenges.

This is one of the smallest, lightest and least expensive lenses you can buy for any camera even those which use the smaller Micro Four Thirds sensor.

The external styling is minimalist in the usual EF-M fashion, with just one small ring for focussing and no other controls.

The optical design is interesting. There are 7 elements in 6 groups. The front element is very small. 

The rear element is a much larger glass moulded aspheric.

The inner barrel moves in and out with focussing suggesting that the whole optical assembly might be moving together. I can’t confirm this as the lens parks itself in the infinity focus position when the body is powered off.

Length 24mm

Diameter 61mm

Mass 105 grams

Filter 43mm

No lens hood is supplied. One is listed by Canon but as it screws into the filter thread I doubt it would be useful. The RF 35mm f1.8 has a similar arrangement and the hood on that lens is pretty much useless.

The mount is metal.

The lens is made in Taiwan.

I use the lens without hood or filter and have had no problems thus far however if I take the lens near the sea I will fit a protect filter to keep salt spray off the front element.

The corners are a bit soft at f2, less so at f2.8 and sharp from f4.

Otherwise the lens is tack-sharp at f2-2.8 across most of the frame and across the whole frame from f4.

Contrast appears to be high.

The lens delivers pictures with impressively  high resolution,  sharpness and clarity.

Bokeh
With f2 available this lens can render a main suject sharp and backgrounds unsharp. So the character of the unsharp parts of the image becomes important. I find this quite pleasing with softly rendered out of focus elements free from  nasty ni-sen (double-line).   

These are mild to insignificant and where detected are easily correctable in an image editor.

This can be induced by deliberately placing the sun near the edge of the frame but is rarely a problem in practice.

My copy is slightly decentered although this is only evident at f2.

Autofocus is sufficiently fast for most purposes although a bit slower than some of the zooms which use a single small inner element for focussing.

AF on the EOS M50 with Canon DPAF is very accurate and reliable.

Manual focus works OK on the M50 but is rarely needed.

The EF-M 22mm f2 is almost a perfect compact lens. It has a usefully wide aperture, is very sharp, very compact  and inexpensive.

The only downside is it lacks a stabiliser.

The first EOS-M had 18 Mpx. Now the M series has 32 Mpx (M6.2). This means camera shake has a greater effect on resolution.

This means that the 22mm f2 needs to use a faster shutter speed (and therefor potentially a higher ISO setting) than would be the case if either the lens or a camera body had a stabiliser.

There are rumors of a new EOS-M camera coming sometime in 2020 (or maybe 2021) with IBIS.  I hope this is so because a body with IBIS would significantly increase the appeal of the already excellent 22/f2.