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| One does not usually photograph birds with a lens like this but the lorikeet was sheltering from some bad weather so he came in close. EOS-M6.2, EF-M 28mm f3.5 Macro. |
Canon is one of the more adventurous lens makers and the subject of this post shows that Canon’s designers can think out of the box with interesting results.
What is the EF-M 28mm f3.5 macro ?
It is a multipurpose prime lens exclusively for cameras with the EF-M lens mount.
It is a true macro, offering 1:1 and even 1.2:1 reproduction in super macro mode, when most Canon lenses labelled “macro” can manage at best a 1:2 reproduction ratio.
It even has two built in LED lights which are handy when the front element of the lens is very close to the subject.
It is a versatile and capable general purpose lens with a focal length equivalent to 45mm in full frame terms.
It focusses quickly and accurately, it does have an image stabiliser and it delivers commendably sharp pictures.
On top of all this it is very compact, light and inexpensive.
Reviewers tend to wax lyrical about Canon’s “big gun” lenses which are large, heavy, expensive and offer excellent optical performance.
But I think the measure of a lens maker is its ability to deliver small, light, low cost lenses of high optical and mechanical quality, good enough for the vast majority of photos most enthusiast photographers will likely want to make.
The EF-M 28mm f3.5 fits this bill perfectly.
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| Mounted on EOS-M50 |
Description
The usual sleek, minimalist EF-M styling is seen again here in gunmetal grey color.
There are two rings, one at the front for focus and a wider one to unlock the inner barrel after pushing forward a little slider switch like that on the kit lens.
Super macro mode is obtained by twisting the control ring to the second marked click position. This works like a built in extension ring.
Construction is all plastic including the mount. Some reviewers decry this but I find plastic very suitable for small lightweight lenses like this one.
There is a cover piece which when unscrewed from the front of the lens reveals the LED macro lights, one on each side of the front element. These are controlled via a little press button giving three lighting conditions, both full, both half, both off.
These low power LED lights are only useful when the subject is very close to the front of the lens.
Dimensions:
Length with front and rear caps, 71mm. This extends 15mm when ready for use.
Diameter of outer barrel 61mm (as are all EF-M lenses to date)
Mass with caps, 163 grams.
The optical construction is interesting.
The front element is only 11mm in diameter. The fixed rear element appears to be flat, like a clear filter, resumably to reduce the risk of dust entry.
The lens proper has 10 elements in 9 groups, all congregated near the front of the inner barrel.
Unusually, the elements in the middle of the construction are larger than those at the front and rear.
There are two aspherics and one UD element. IS operates on the third element from the front. Canon says this is a hybrid type stabiliser apparently optimised for macro work.
It appears likely that the whole optical construction moves when focussing, I am not sure about that and of course the lens cannot focus when it is off the body.
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| Block diagram EF-M 28mm f3.5. The front element is on the left |
Mechanical functions
The twist-to-open action is nicely smooth. The front ring actuates focus by wire which works well.
Some reviewers have complained that it is too easy to twist the lens barrel past the normal operating position onto the super macro position.
Autofocus is noticeably faster and more positive than we find on the EF-M 32mm.
On my tests IS allows me to hand hold at 2.5 EV steps slower shutter speed than without IS. This is in line with Canon’s specifications. This might not sound like much when Canon is claiming 8 stops for its latest full frame models but 2.5 stops is still useful and allows me to hand hold down to 0.3 seconds and still get sharp pictures.
Centering on my copy is good with a just detectable difference between right and left sides at f3.5.
I tested for shutter shock using the mechanical shutter on the EOS M6.2 and found no significant problem in the shutter speed range 1/30-1/400sec. There was perhaps some slight loss of acutance at 1/100 and 1/125 second but it was very subtle at most.
Optical performance
Sharpness/acutance. The 28mm is commendably sharp at all apertures with mild softening in the corners at the widest apertures.
It is not in the same class as the amazing 32mm f1.4 at the widest apertures but neither is any other lens I have used or tested.
By f5.6-f8 the 32mm f1.4, 22mm f2 and 28mm f3.5 are quite evenly matched for optical capability although the 32mm still has a slight edge across the frame.
Close-up sharpness is good across the frame as you would expect from a proper macro lens
Sharpness starts to decline due to diffraction at the aperture diaphragm from about f10.
Bokeh is nice and smooth.
Distortion is barely detectable and of pincushion type.
Flare can be a problem with the sun at or near the frame edge (inside or outside). It pays to keep sun off the front element.
Peripheral shading is moderate at f3.5, becoming less as the aperture is closed.
Color fringing can occasionally be seen at high contrast edges near frame boundaries but is rarely a problem and is easily managed in post processing.
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Summary
Although Canon’s inventory of lenses for the M system is limited in number it does include some interesting, adventurous and practical designs of which the 28mm f3.5 macro is one.
It works well either as a real macro or as a general purpose lens, with good sharpness and other optical characteristics, useful IS and fast, accurate autofocus.
I find that although the 32mm f1.4 has slightly better ultimate sharpness I prefer using the 28 macro for general photography because of the IS and fast, confident focussing.
Recommended.