Overview

The Sigma AF 18 mm f/3.5 is a compact, lightweight wide-angle lens with solid build quality. Optically, it offers good center sharpness but suffers from soft corners and noticeable chromatic aberration, especially wide open. Distortion and vignetting are present but correctable. Its handling is straightforward with a smooth focus ring. This lens suits budget-conscious photographers seeking an ultra-wide option for landscapes or architecture, provided they can manage its optical flaws.