Lens review
Canon EF 40 mm f/2.8 STM
11. Summary
- a nifty, compact casing,
- excellent image quality in the frame centre,
- good image quality on the edge of the APS-C sensor,
- right correction of chromatic aberration,
- slight distortion,
- practically no astigmatism,
- moderate vignetting on the APS-C sensor,
- very good work against bright light,
- silent and accurate autofocus,
- good price/quality ratio.
Cons:
- huge vignetting on full frame.
The results of the Canon EF 40 mm f/2.8 STM are a very nice surprise. Preparing myself for testing this “pancake” I expected a lot of problems on the edge of full frame sensor. There were some problems but not very serious ones – you can easily wave them aside. The mere comparison of the cons and pros lists proves this device is really worth your interest.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
You can also wonder why the producer didn’t implement a bit faster aperture. The combination of f/2.8 and 40 mm focal length is available for every user of 24-70 mm f/2.8 class lens or a 17-55 mm f/2.8 device for smaller sensors. Still you should remember that such constructions are expensive and optically they can fare worse than the “pancake” tested here. Full frame has also a bigger potential so the Canon 2.8/40 will be able to provide a shallower depth of field than the Panasonic G 20 mm f/1.7 ASPH, so praised and valued in the little world of mirrorless devices.
Sample shots



