Leica Summilux-SL 50mm f/1.4 ASPH - 2026 version. Launched alongside the new Leica SL3-P camera, the Leica Summilux-SL 50mm f/1.4 ASPH claims to be the world's most compact 50mm f/1.4 autofocus lens. At just 75.5mm long and with a diameter of 74mm, it is a substantial shrinking of the original Leica 50mm f/1.4 SL lens launched back in 2016. In 2023, Leica introduced a smaller version of its Summicron-SL 50mm f/2 ASPH.