New Website Reviews Waterproof Binoculars WaterproofBinocularsReview.com is a new site providing reviews from waterproof binoculars buyers taken from many websites to help other consumers take smart buying decisions. Source
WaterproofBinocularsReview.com is a new site providing reviews from waterproof binoculars buyers taken from many websites to help other consumers take smart buying decisions.
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Standard roof prisms have several inherent design difficulties. First, they are not as bright as Porro prisms because they employ mirror surfaces that lose some light. Second, alignment is often more critical than in Porro prisms; an alignment error a fraction of the width of a human hair will degrade the image in a roof prism. Securing them in binoculars is much more of a challenge. Third, images are split and then rejoined slightly out of phase when they pass through such a prism. This produces an image of slightly less resolution than an equal quality Porro prism.Thus we have a trade-off: the slight optical superiority of the typical Porro prism versus the comfort factor of the standard roof prism. Yes, average quality Porro prisms tend to give a sharper image than standard roof prisms. There is a price to pay for comfort.
Better Porro prisms binoculars are made from a high density glass, BAK-4. If you hold binoculars away from your eyes and up to the light, you can see the circular exit pupils in the eyepieces. The less expensive BK-7 prisms will have squared-off, non-circular exit pupils.
It is well worth a step outside the next clear, dark night, despite the late-autumn chill. Even a few minutes with eyes alone will allow you to sweep across half of the universe all at once - given you are in an open field or out on a lake, or maybe on your rooftop.Be sure to allow a few minutes to let your eyes adapt to the darkness; you can do this in the warmth of your home, with the lights off.