HD PENTAX-DA 18-50mm f/4-5.6 DC WR RE

JP 2016-6455 A — Tomoya Koga

11 ELEMENTS / 8 GROUPS
18-50mm F4-5.6
0.3m MFD
1 HYBRID ASPHERICAL SURFACE
1 ANOMALOUS-DISPERSION ELEMENT

Focus Mechanism

PUBLISHED: G1b (hybrid L12 + L13) moves objectward from infinity to the patent's 300 mm state; D2 decreases while D7 increases by the same travel at each zoom station. No internal focus reconstruction is used.

Optical Elements (11 physical; 12 modeled media)

ElementTypeGlass
L11Negative Meniscus804466 (vendor unresolved)
L12gBiconcave Negative (Hybrid Substrate)497816 (vendor unresolved)
L12rBonded Aspheric Resin LayerUnmatched (synthetic resin layer; chemistry unpublished)
L13Positive Meniscus805254 (vendor unresolved)
L21Biconvex Positive618634 (vendor unresolved)
L22Biconvex Positive487702 (vendor unresolved)
L23Negative Meniscus847238 (vendor unresolved)
L31Positive Meniscus805254 (vendor unresolved)
L32Biconcave Negative788474 (vendor unresolved)
L41Positive Meniscus618634 (vendor unresolved)
L42Biconvex PositiveS-NSL5 (OHARA catalog equivalent for patent 522598; production supplier unspecified)
L43Negative MeniscusS-NBH55 (OHARA catalog equivalent for patent 800299; production supplier unspecified)