The SD series of roof prism binoculars have an objective lens diameter of more than 40 mm. Equipped with the same high-quality coatings of the A-series, perfect image quality is guaranteed. The characteristic of this series is their brightness due to the large objective lens diameter.
The lenses of the S series of binoculars are specially coated with a protective lens coating. This nanotechnology-based hydrophobic protective coating of the outer optical elements deflects water, oil, dust and dirt to permanently prolong visual comfort. This means that these PENTAX binoculars are impressive even under the toughest viewing conditions.