Canon EF 40mm f/2.8 STM Review

4.5
June 26, 2013 | Mark Goldstein |

Introduction

The Canon EF 40mm f/2.8 STM is a pancake prime lens for APS-C and full-frame DSLR cameras. Offering continuous AF while capturing video with compatible cameras, the ultra-slim Canon EF 40mm f/2.8 STM retails for just £229.99 / €279.99 / $199.99. Read our in-depth Canon EF 40mm f/2.8 STM review complete with full-size sample images to find out if it's worth the modest outlay.

The EF 40mm f/2.8 STM is Canon’s first ever EF pancake lens. Featuring a fixed focal length of 40mm and bright f/2.8 aperture, Super Spectra coatings that minimize ghosting and flare, a circular seven-blade aperture, a newly developed stepping motor for smooth and quiet continuous AF while capturing video, and a short minimum focusing distance of only 0.98ft/0.30m, the ultra-slim Canon 40mm f/2.8 lens is ideal for portrait, reportage, travel and landscape photography. The Canon EF 40mm f/2.8 STM is available now for £229.99 / €279.99 / $199.99 in the UK, Europe and the USA respectively.

Ease of Use

Canon EF 40mm f/2.8 STMThe Canon EF 40mm f/2.8 STM lens

Canon EF 40mm f/2.8 STMThe Canon EF 40mm f/2.8 STM lens

Canon EF 40mm f/2.8 STMThe Canon EF 40mm f/2.8 STM lens

Weighing a mere 130g and measuring 22.8cm in length, the Canon EF 40mm f/2.8 STM is one of the tiniest lenses that Canon offers. You can use it on a Canon EOS APS-C body like the 700D that we tested it with for a short-telephoto 64mm equivalent angle of view, and it also balances well on a full-frame camera like the EOS 6D, providing a more "normal" field of view.

Canon EF 40mm f/2.8 STMSide of the Canon EF 40mm f/2.8 STM lens

Canon EF 40mm f/2.8 STMSide of the Canon EF 40mm f/2.8 STM lens

Canon EF 40mm f/2.8 STMTop of the Canon EF 40mm f/2.8 STM lens

As you would expect from such an inexpensive lens, build quality is good rather than outstanding. The Canon EF 40mm f/2.8 STM feels solid in your hand, despite the all-plastic construction, with a metal mount adding to the solidity. The focusing ring is very narrow but has a ridged, rubberised grip band that assists with the finger-tip operation.

Canon EF 40mm f/2.8 STMFront of the Canon EF 40mm f/2.8 STM lens

Canon EF 40mm f/2.8 STMFront of the Canon EF 40mm f/2.8 STM lens

Canon EF 40mm f/2.8 STMRear of the Canon EF 40mm f/2.8 STM lens

The only other control on the lens barrel is a focus mode switch with the usual AF/MF settings. Note that this lens offers full-time manual focusing even when AF is selected.

Canon EF 40mm f/2.8 STMFront of the Canon EF 40mm f/2.8 STM lens

Canon EF 40mm f/2.8 STMRear of the Canon EF 40mm f/2.8 STM lens

Canon EF 40mm f/2.8 STMThe Canon EF 40mm f/2.8 STM lens in-hand

The lens doesn't ship with either a lens hood or a protective bag. It accepts 52mm filters.

Focal Range

At the 40mm focal length the angle of view is 57°30'.

 Sigma 35mm F1.4 DG HSMField of view at 40mm

Focusing

Given its tiny size, the Canon EF 40mm f/2.8 STM lens understandably has a very narrow focusing ring. Manual focusing is of the electronically-driven, 'focus-by-wire' type, more typically found on compact system cameras. There are no hard stops at either ends of the range, making it more difficult to set focus at infinity. Polariser users should be pleased that the 52mm filter thread doesn't rotate on focus.

When it comes to auto-focusing, the Canon EF 40mm f/2.8 STM zoom is a fairly slow performer, taking about 0.3 seconds to lock onto the subject when mounted on the Canon EOS 700D that we tested it with.

We didn't experience too much "hunting" though, either in good or bad light, with the lens accurately focusing almost all of the time. It's also a quiet performer, thanks to the built-in STM (Stepping Motor), which makes this lens well-suited to video recording.

Chromatic Aberrations

Chromatic aberrations, typically seen as purple or blue fringes along contrasty edges, are impressively well controlled with this lens - the examples below show the worst-case scenario.

Canon EF 40mm f/2.8 STM Canon EF 40mm f/2.8 STM

Light Fall-off

With the lens wide open at f/2.8, you can't really see any light fall-off in the corners, and distortion is also very well controlled.

Canon EF 40mm f/2.8 STM

Macro

The Canon EF 40mm f/2.8 STM is not really a macro lens, but the close-focus point is a useful 30cm from the film/sensor plane, and Canon quotes a maximum reproduction ratio of 0.18x for the lens. The following example illustrates how close you can get to the subject, in this case a CompactFlash card.

Canon EF 40mm f/2.8 STM Close-up performance

Bokeh

Bokeh is a word used for the out-of-focus areas of a photograph, and is usually described in qualitative terms, such as smooth / creamy / harsh etc. One of the reasons to buy a fast lens is to be able to isolate the subject from the background, and the Canon EF 40mm f/2.8 STM has an iris diaphragm with 7 rounded blades for a pleasing rendering of the out-of-focus highlights. Below you'll find some examples, but you are also encouraged to check out our sample images.

Canon EF 40mm f/2.8 STM Canon EF 40mm f/2.8 STM
   
Canon EF 40mm f/2.8 STM Canon EF 40mm f/2.8 STM

Sharpness

In order to show you how sharp this lens is, we are providing 100% crops on the following page.

Entry Tags

lens, canon, f2.8, prime, standard, telephoto, ef, normal, pancake, stepper, stm, stepping, 40 mm, 40mm, Canon EF 40mm f2.8 STM Review, 64mm

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