Canon EF 24mm f1.4L II USM Lens has the brightest large-diameter f/1.4 high-performance wide-angle L lens in the 24mm class (as of July 2008)

UD glass and high precision GMo aspheric lenses correct chromatic aberration
Minimal flare and ghosting
Fast and silent AF via high-speed CPU, optimised AF algorithm, rear internal focusing and ring USM drive
Circular aperture diaphragm allowing striking blur effects
Manual focusing enabled even during AF mode
High resistance to dust and water droplets
Only environmentally friendly lead-free glass used in lens construction

Ultra-Wide & Wide Lenses

Professional wide-angle lens with an ultra-large maximum aperture of f/1.4.
Employs a replicated aspherical lens element to suppress distortion and
spherical aberration, and two UD lenses to correct lateral chromatic
aberration. Waterproof and dust resistant properties make this lens suitable
for taking pictures even in harsh weather condition.