90–230mm · f/4.5
The Mamiya/Sekor Zoom SX 90-230mm f/4.5 Auto is a modernized Tokina design from the 1960s, known for being sharp wide-open but prone to color fringing. It focuses closer than the original version (under 2m) and holds focus while zooming. Build-wise, it lacks a manual-auto switch and has an extra pin that complicates mounting on DSLRs, though the pin can be removed or modified. This lens suits users comfortable with DIY modifications and seeking a compact, sharp vintage zoom for M42 mounts.