I was looking forward to testing the Canon EF 40/2.8 STM: I’m partial and fond of pancake lenses, and Canon doesn’t often indulge its thrifty users with new products.
| Optical construction: 6 elements in 4 groups, including 1 aspherical element |
| Aperture range: f/2.8 – f/22 |
| Number of aperture blades: 7, rounded |
| Light filter diameter: 52mm |
| Minimum focus distance:30 cm |
| Maximum magnification: 0.18x |
| AF motor: STM motor |
| Dimensions: 68.2*22.8mm |
| Weight: 130 grams |
Package Contents
Funny the difference in the size of the boxes the Canon EF 40/2 is sold in.8 STM and EF 50/1.8 II: the novelty obviously tries to assert its seriousness at once – the lens is smaller and the box is larger. The package doesn’t correspond to the box dimensions: lens, front and back covers, standard set of papers – manual and warranty card. Canon ES-52 hood is optional.
Boxes
Set
Quality of materials and workmanship, ergonomics
No complaints about the quality of the materials. The plastic is nice, the manual focus ring is covered with rubber, the body mount is metal. No backlash, all tightly assembled.
Controls are limited to the manual focus ring and focus mode switch. The manual focus ring at the front of the lens is a convenient and logical solution. It is easy to find without looking and without fear of jabbing your finger at the front element: it is very small and its visible part has a diameter of only 19 mm.
Canon EF 40/2.8 STM uses “electronic manual focus”, which is traditional for blinx lenses of recent development: the manual focus ring has no mechanical connection with the focusing elements, the rotation of the ring only gives a signal to the autofocus motor to move the elements accordingly.
Front view
Back view
Canon EF 40/2.8 STM uses a stepping motor which is new to STM lenses and is discreetly mentioned in the name of the lens. Let’s leave aside the claims of “smoothness, noiselessness and special adaptability of such drives for video mode”: the main argument in favor of this solution is seen in the possible miniaturization of such motors and less complicated mechanics of the focusing drive.
Front element does not rotate in focus, but lens resizes by pushing the optical unit forward 7mm to the position of the minimum focusing distance. Canon EF 40/2.8 STM focuses by moving all the optics at once. There is practically no play in the forward extending trunk.
Canon EF 40/2.The 8 STM is fun and handy to use, no major complaints about ergonomics and looks funny and unfamiliar on the camera.
Geometric distortions
Canon EF 40/2.The 8 STM passed the test with flying colors and a very slight barrel distortion of 0.7%, an excellent result. Especially considering the fact that geometry is a sore subject for pancake lenses and most of them have a tendency to have an increased level of distortion.
Distortion
Resolution and sharpness
This metric is usually the most correlated with the price of a lens besides the quality of materials and workmanship , which is why the EF 50/1 is so popular.8 II is a compromise lens in general, but offers very good sharpness.
Canon EF 40/2.I really liked the 8 STM, so I was cautious when it came to the resolution test – I didn’t want to be disappointed. Not only did the lens not disappoint, but it exceeded expectations: everything is just fine and the Canon EF 40/2.8 lets you use it without hesitation at all working apertures, including the fully open one.
Center is excellent at all apertures, approaching the resolution of the Canon EOS 5D mark II sensor at f/4 and f/5.6. The edges and angles are naturally different, but not beyond “very good” even at f/2.8.
A serious consideration when choosing from 3 relative competitors – the hero of the review, the Canon EF 50/1.8 II and Canon EF 35/2.0 is excellent at the f/2 aperture.8 certainly don’t eliminate the lag in aperture ratio completely, but they level it out seriously – at f/2.8 STM and 30 STM have worse edge and corner impressions.
Overall, the most convincing results without regard to the price of the lens. The Canon EF 40/2.8 STM is able to compete with much higher-priced lenses.
| f/2,8 | f/4,0 | f/5,6 | f/8,0 | f/11 | f/16 | |
| Center | 86% | 100% | 99% | 96% | 85% | 77% |
| Middle | 76% | 85% | 87% | 86% | 78% | 72% |
| Angle | 73% | 83% | 84% | 84% | 77% | 70% |
| 87% | 100% | excellent |
| 73% | 86% | very well |
| 60% | 72% | well |
| 46% | 59% | acceptable |
| 45% | bad |
Vignetting at f/2.8
Vignetting
Canon EF 40/2.8 The STM is fairly conventional: vignetting is present at all apertures, the effect diminishes as the aperture gets closer.
At full open, darkening in the corners of the frame reaches 2.7 stops, which is frankly not great, but not much different from the performance of peer lenses. Already by f/4.0 Vignetting is reduced to a relatively non-irritating 1.1 stops, but is then present at acceptable values of 0.9 to 0.7 degrees.
Autofocus drive
Focusing
The STM motor feels and prefers to be somewhere in the middle between a USM motor and a conventional micromotor: the autofocus speed is clearly inferior to the USM motor and comparable to the autofocus speed of lenses with conventional motor drives. The quietness of the STM drive is a bit exaggerated: it’s definitely quieter than a normal micromotor, but the sound of operation is present and audible.
It has been suggested that the Canon EF 40/2.8 STM slower than the competition – EF 50/1.8 II and EF 35/2. It’s not: it takes about 1 second to go from infinity to the closest focusing distance. I think the great “smoothness” of the process compared to sharp and loud, e.g. Canon EF 50/1.8 II leads to a subjective feeling of slowness. I have no complaints about the sharpness and most importantly the accuracy of the autofocus.
The specimen we tested had no focus shift when changing the aperture, which has been mentioned in several reviews. Manual focus is possible regardless of the enabled mode, however, in AF mode only when the shutter/exposure metering button is half-pressed.
The ring is positioned as comfortably as possible for a lens of this size. The stroke is smooth, almost 180 degrees enough for comfortable operation. The slight delay in response inherent in lenses with electronic manual focus is present.
CA at f/2.8
Chromatic aberration
Canon EF 40/2.8 STM is frankly a delight. I was waiting for a catch – excellent sharpness, very little distortion, non-criminal vignetting – I was kind of expecting an ambush from a $200 lens. But it did not disappoint here either: at the fully open aperture the chromatic aberration width at the edges of the frame was 0.85 pixels. CA may be noticeable in critical situations, but the index is very good.
At f/4.0 0.75 pixels wide
0.72 pixels at f/5.6
0.85 pixel at f/8.0
Out-of-focus area coloring
Out of focus area coloring
No complaints: some green/magenta blurring at f/2.8, but extremely slight. Already at f/4.0 – no trace. That’s a great result.
Conclusion
Add to the test results good contrast already at fully open aperture, confident performance in difficult lighting conditions it is almost impossible to catch artifacts regardless of the light source location even without lens hood , very good color reproduction, extremely friendly weight, size and price – you get an undoubtedly “honest” lens.
Complain about somewhat sluggish focal length? It’s more out-of-focus than out-of-focus. From my point of view as a person who is cracked by Poltinas it’s a great focal length for “everything” both on full frame cameras and on APS-C models where Canon EF 40/2.8 STM will match64 mm. A great lens at a great price – highly recommendable. I think it will take potential buyers away from the Canon EF 50/1.8 II, EF 35/2, and the 50/1.4 has a serious competitor.
I would like to know how the Canon EF 40mm f/2.8 STM lens performs in terms of image quality and focusing speed. Are there any noticeable aberrations or distortions? How does it handle low-light situations? Is it suitable for both photography and videography? Additionally, I would be interested in hearing about its overall build quality and durability. Any insights on its performance and value for money would be greatly appreciated!