The new Canon EF 40mm f/2.8 STM ($199, click here) is getting very good reviews, so it’s time to compare it to other lenses, in our case to the Voigtländer 40mm f/2 SL-II ($499, click here) lens. The comparison was done by Photo Pensieve.The Voigtlander is a manual focus lens, has faster aperture, better build quality and costs $300 more. Nevertheless, I think the comparison is interesting. The little Canon pancake doesn’t fall short when it comes to positive surprises (as seen in previous reviews, here and here). The review/comparison is fairly exhaustive, with lots of sample images and technical details. From the conclusion:

 […] I did not expect that it beats the sharpness of already excellent Voigtlander 40mm F2.0, but it did. It is also showed more resistance to flare. […]The canon is much cheaper than the Voigtlander, but its built quality is not in the same league as the Voigtlander’s. Although the Canon is built very well, and at least considerably better than the 50mm F1.8 and 35mm F2.0. The only shortcoming that I can see with the Canon is that it does not focus fast, like the Canon 85mm f1.8, for example. But if you compare the autofocus speed on the Canon with “your” manual focus speed with the Voigtlander, it’s a no-brainer.[…]

So all in all, if you need f2.0, shallower depth of field, love the metallic lenses, and are ok with focusing manually, the Voigtlander is the choice. Otherwise, the Canon is a tiny bit Sharper (specifically in the corner, wide open), more resistant to flare, punchier, slightly wider, considerably cheaper and lighter, and it does AUTOFOCUS.[…]