Overview

The Viltrox AF 40mm F2.5 is a budget-friendly full-frame prime ($150–$158) with solid build using engineered plastics and a metal mount, though lacking weather sealing. Optically, center sharpness is very good wide open, with soft corners that improve by f/5.6; lateral chromatic aberration affects corner sharpness. Distortion is moderate pincushion (~2%) without profile correction. Autofocus is fast and quiet via STM motor. It suits street and everyday photographers seeking a compact, affordable 40mm lens that bridges 35mm and 50mm perspectives.