The GR lens has been imbued with our unique optical technology that aims to always provide high image quality. The GR III uses a slim optical system consisting of 6 elements 4 groups with a focal length of 18.3 mm (approx. 28 mm in 35 mm equivalent focal length) and aperture of F2.8. The GR IIIx uses a newly developed optical system consisting of 7 elements 5 groups with a new focal length of 26.1 mm (approx. 40 mm in 35 mm equivalent focal length). High-refractive index low-dispersion glass lenses and aspherical high-precision molded glass lenses are optimally placed in the lens construction according to each model’s optical system to suppress optical distortion and chromatic aberration to the absolute limit, delivering a high level of sharpness. This results in images that are sharp and clear across the entire frame even from the full aperture setting.