PENTAX HD DA 55-300mm f/4.5-6.3 ED PLM WR RE

Focus Mechanism

G4 (L41 and L42) moves toward the image for closer subjects, as the patent describes: d22 grows and the back focus shrinks by the same amount. The patent tabulates infinity focus only. The close spacings are paraxial solves for Ricoh's 0.95 m minimum focus distance, with G4 travel of 0.91 mm at 56.5 mm, 4.04 mm at 132.1 mm and 11.82 mm at 291.2 mm (about 0.30× at the long end). Eight finite focus positions are solved at every zoom position; the slider interpolates between them.

Optical Elements (14 physical)