Ricoh made both a XR version without the zoom pin, and the P version which has it. Rikenon 24 mm f2.8 (52 mm filter)XR Version Rikenon 28 mm f2.8 (52 mm filter)XR Version Rikenon 28 mm f3.5 (52 mm filter)XR Version (probably a renamed smc PENTAX-M 28mm f/3.5, very sharp wide-open) Rikenon 35 mm f2.8 XR Version Rikenon 50 mm f2 (52 mm filter)XR Version Rikenon 50 mm f2 L (52 mm filter)XR Version Rikenon 50 mm f2 S (52 mm filter)XR Version Rikenon 50 mm f1.4 (52 mm filter)XR Version Rikenon 50 mm f1.7 (52 mm filter)XR Version Riconar 55 mm f2.2 (52 mm filter) Rikenon 55 mm f1.2 (58 mm filter)XR Version Rikenon 135 mm f2.8 (55 mm filter)XR Version Rikenon 200 mm f4 XR Rikenon 50 mm f2 (52 mm filter)P Version Rikenon 600 mm f8 Reflex XR Version Rokinon This lens uses the Ricoh KR-mount version: Rokinon 500 mm f6.3 Reflex (catadioptric) Sakar Sakar is a commercial American company that used to sell K-mount lenses. 80–210 mm f1:3.8 macro MC (58 mm filter) 85–210 mm f1:4.5 macro MC 500 mm f/8 macro mirror (catadioptric) Samyang Samyang is an optical manufacturer located in South Korea. Many of their lenses are also sold under the Rokinon and Bower brand names. Samyang 8 mm f/3.5 UMC Fish-eye CS II Samyang 10 mm f/2.8 ED AS NCS CS Samyang 12 mm f/2.8 AS NCS Fish-eye Samyang 14 mm f/2.8 ED S IF UMC Samyang 16 mm f/2.0 ED AS UC CS Samyang 20 mm f/1.8 ED AS UMC Samyang 24 mm f/1.4 ED AS IF UMC Samyang Tilt/Shift 24 mm f/3.5 ED AS UC Samyang 35 mm f/1.4 AS UMC Samyang 50 mm f/1.4 AS UMC Samyang 85 mm f/1.4 AS IF UMC Samyang 100 mm f/2.8 ED UMC Macro Samyang 135 mm f/2.0 ED UMC Samyang 100–500 mm f5.6-7.1 Macro Tele Zoom Lens Samsung All these lenses had been marketed by Samsung and present on Samsung's GX-series DSLRs. Schneider-Kreuznach is a traditional optics maker that do still make specialised glass and lenses (today mainly high-quality large-format lenses, enlarger lens and photographic loupes), but not for Samsung. They license their name to Samsung granted that certain minimum quality requirements are fulfilled. All the Schneider branded glass from Samsung is manufactured by Pentax and corresponds directly to Pentax lenses. Schneider-Kreuznach D-Xenogon 10–17 mm F3.5-4.5 ED (2007- ) (rebadged Pentax DA 10-17mm