Celestron 71198 Cometron 7x50 Porro Prism Binoculars, Black

Product Information

Thus compared to higher end optics, these will capture and transmit less light and thus produce a less bright image. Field flattener Lenses – the fact that Fujinon has incorporated field-flattener lenses into the Polaris series is a definite indication of their very high quality. Most waterproof binoculars have a fixed focus: this solves the problem of sealing the nitrogen gas within moving parts. Fully Multi-Coated – Every lens surface throughout the entire optical pathway on these Sightron SII Binoculars has multiple layers of an anti-reflection material added to them.

This is used to compare how well binoculars with different size exit pupils can perform under dark conditions: equals the square of the exit pupil diameter. So at high powers, it can be hard to locate a particular star or planet because you lose all your reference points around it.The instrument is fitted with an illuminated compass with distance scale projected into the left hand eyepiece. So, rubber covering is fine to protect from knocks and stop them sliding around, but it’s no guarantee they are waterproof. Their large exit pupil captures brighter images in low light conditions, perfect for stargazing with impressive detail. In addition, the Topas has an integrated illuminated magnetic compass and a reticle for determining sizes or distances with help of the ring scale on the objective barrel.

At dusk and at night we compared them by looking at distant objects: Ryde church tower was a favourite. The compass light was at the right level for night-time viewing, although there was some flare into the line of vision. All models feature high quality BaK-4 prisms and fully multi-coated optics to ensure the very best contrast and light transmission, essential for good astronomical binoculars. There can be no doubt that there are many occasions at sea when the use of a good pair of marine binoculars greatly enhances safety.Prism Glass Glass – These use the cheaper BK-7 prism glass, whereas higher end binoculars will use better quality glass like BaK-4 that has a lower bubble count, fewer imperfections and thus generally delivers a higher quality image. The Weems PRO 7x50 binoculars are loaded with features for discriminating professional sailors and mariners.