From the Manufacturer
The Ricoh A12 50mm f/2.5 Macro GR lens uses a 23.6 x 15.7mm (APS-C size) CMOS sensor with approximately 12.3 megapixels. In combination with image processing engine GR ENGINE III, it achieves high-image-quality photography with high definition, low noise, and smooth tonal gradations. A newly-developed GR Lens with an 8-group, 9-element configuration (aspherical lens: 1 element, two surfaces) is featured. Representing a further advancement in the GR tradition of high image quality, the lens thoroughly corrects for various types of aberrations. Despite the compact size, it is also a full-fledged macro lens with a floating lens structure. At shooting distances from infinity down to the 1/2x maximum magnification macro range, it achieves strong imaging power all the way to the edge of the frame. In addition, the low level of vignetting means that the photographer can enjoy rich and genuine bokeh effects. The manual focus ring is perfect for use in macro photography as it makes highly precise focusing possible. It can also be used to make fine manual adjustments to the focus after autofocus is done.
Ricoh Gr Lens A12 50mm F2.5 Macro - Ricoh 170393.