Pentax Binoculars UP 8-16x21 Black Review

The binoculars of the UP series are compact, lightweight and highly mobile while maintaining good optical qualities. Among all binoculars of the PENTAX UP 8-16x21 series, it stands out for having a variable optical zoom (zoom). All lenses of the binoculars have proprietary multi-coating and provide high image contrast. The design of each binocular lens includes 2 elements in 1 group. The eyepiece has 4 elements in 3 groups. The optics of the PENTAX UP 8-16x21 uses a PORRO prism to normalize the image and shorten the binocular lens length. Large binocular magnification is achieved by increasing the focal length of the telescopes. If there were no prisms, then the binoculars would be much longer, and the prism, making a break in the rays, lengthens their path, thereby making it possible to make the same optical instrument shorter. In addition, if there were no prisms, we would see the image inverted horizontally and vertically. With such an image, it is very difficult to follow the object of observation. Two prisms inside the binoculars unfold the image in the form familiar to us. The PORRO prism makes the binoculars wider and enhances the 3D effect of the image in the binoculars due to the greater distance between the front lenses of the binoculars. Due to the greater binocularity in binoculars with a PORRO prism, it is more convenient to determine the distance to the object of observation. When using a PORRO prism, the optical elements are not on the same axis, so such binoculars must be handled more carefully so as not to disturb the alignment. Due to the type of prism, binoculars with a PORRO prism initially give a contrasting and sharp image, since they do not have ROOF problems of prisms that require correction. center, but also along the edges of the image. Focusing systemPENTAX UP 8-16x21 binoculars are focused by the central focusing ring. It is large enough, and has a corrugation so that it can be easily found by touch, without looking up from the eyepieces. PENTAX UP 8-16x21 binoculars can be adjusted to your vision in a wide range, diopter correction +/-4 D. Using the ring on one of the eyepieces, you adjust the diopter for your eye, and the central ring, which is located between the two telescopes of the binoculars, you focus on the object itself. Central focusing is a very accurate and convenient type of focusing, which makes it possible for PENTAX UP 8-16x21 binoculars to aim at an object at a distance of 3 m and up to infinity. Such a minimum focusing distance is a great advantage in work. It is possible to use PENTAX UP 8-16x21 binoculars with glasses. To do this, the eyepieces of the binoculars are retractable, having intermediate positions (feet) for more precise individual adjustment. But the binoculars have a small eye relief (14-11 mm),