Overview

The SMC Pentax-A 645 120mm f/4 Macro is a manual-focus lens known for excellent build and smooth focusing. Optically, it has no visible distortion and little light falloff, but corners are soft at f/4 and infinity, improving when stopped down. On the GFX 100S at 1:1, it outperforms the Fuji 120/4 GF macro on-axis but remains soft on the right edge. It suits macro photographers who prioritize handling and value, as it is a bargain compared to newer AF versions.