The 24mm World Cup
Group C: Regular f2.8 Prime Lenses

Canon 24mm f2.8 v Olympus 24mm f2.8 v Sigma 24mm f2.8 v Yashica ML 24mm f2.8:
Corner Performance at f2.8 (100% Crops)

3 points	3 points
Canon 24mm f2.8 SuperWide at f2.8 (corner)	Olympus 24mm f2.8 at f2.8 (corner)
Sigma 24mm at f2.8 (corner)	Yashica ML 24mm f2.8 (corner)
2 points	1 points

The Canon 24mm f2.8 has a distinctive, almost Sigma-like, yellow cast and is arguably the best corner performer of the bunch. Certainly it retains the best contrast out in the corners, but the resolution isn't quite as good as the Olympus 24mm f2.8. To be fair, none of these are stunning at this aperture. The Sigma and Yashica ML fall distinctly into second and third place behind the class-leading Olympus and Canons.

Centre Performance at f2.8 (100% Crops)

1 points	4 points
Canon 24mm f2.8 SuperWide at f2.8 (corner)	Olympus 24mm f2.8 at f2.8 (corner)
Sigma 24mm at f2.8 (corner)	Yashica ML 24mm f2.8 (corner)
2 points	3 points

Centre frame, the Olympus just outresolves the Sigma and Yashica. The Sigma is a bit unlucky to walk away with just two points from this comparison because in reality it's very close to the Olympus. The clincher is its weakness for chromatic aberration. The Yashica looks well behaved in this regard. Following its nicely rendered corners, the Canon looks much less attractive centre frame compared with the more neutral competition.