Olympus Zuiko Auto-Zoom 50-90mm f3.5 Focal Length: 50mm Aperture: Open f3.5@‘S‘ฬ‘œA’†‰›E‰E’[Eถ‰บ’[‚ฬŠg‘ๅ‘œ‚ฬ‡‚ษ•\Žฆ –Žฉ“ฎi‚่Œฬแ@˜Io‰฿่’ˆำ@Kenko PRO ND-4 FilterŽg—p