Super images, especially considering the size and price. On an APS-C body, it's a 60mm "normal" lens that's biting sharp wide open, edge to edge. Keep it in your front pocket. On full frame it's a little soft wide open, but still charming. I hope Canon continues to make lenses like this.

Awesome "normal" lens for APS-C

Focus a little slow

Bought for my 6D so I could take it to work, have a compact light package but still being full frame. People might sniff at the fact the lens is only 2.8 but for most every day uses this is all you need.

The 40mm is always ready for use, it is so thin it is almost a mirror cover, but whip it out and snap snap away, yes it may not be the best lens in canons line up, but sheer conveinence it wins hands down. It has good bokeh and can get quite close to a subject without distortion of the lines.

A low-profile lens for street photography, suited for full-frame cameras...

Extremely slim and lightweight; Excellent optical quality

Unsophisticated focus system; Thin manual focus wheel

Canon is the only major Japanese camera manufacturer who has been shy of entering the mirrorless market (as of the time of this review). So far their reps always argued that it is possible to design smallish APS-C DSLRs that are also able to compete on the size and weight side.

It's impressive what Canon has managed to pack into a very small package here. Excellent results for sharpness, CA and distortion, and only some corner shading when used wide open on full-frame - which you could call the "character" of this lens. For the price, it's well worth the money.

The EF 40mm F2.8 STM offers excellent image quality in a tiny, well-made package. For APS-C users it provides a great carry-everywhere complement to a kit zoom, and for full frame shooters it's an excellent general-purpose 'normal' lens. The STM motor means that autofocus is almost completely silent, but it's not super-fast.

Canon SLR owners who want the image quality of a prime in a tiny, relatively inexpensive package.;

Photographers shooting in really low light or aiming for maximum background blur. They'll do better with a faster lens like the EF 50mm F1.8 II;