{"id":36198,"date":"2023-03-07T07:14:52","date_gmt":"2023-03-07T07:14:52","guid":{"rendered":"https:\/\/telescopenights.com\/?p=36198"},"modified":"2023-04-17T04:21:51","modified_gmt":"2023-04-17T04:21:51","slug":"bak4-vs-bk7-and-k9","status":"publish","type":"post","link":"https:\/\/telescopenights.com\/bak4-vs-bk7-and-k9\/","title":{"rendered":"From Bak4 to BK7: Which Prism Glass Is Right for You?"},"content":{"rendered":"
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\"bak4<\/figure><\/div>\n\n\n

When choosing binoculars or spotting scopes, you’ll notice different glass types mentioned. Which glass is better for image quality?<\/p>\n\n\n\n

BaK-4 offers a brighter and rounded image compared to BK-7 but is more expensive of the two. The K-9 type is equivalent to BK-7.<\/p>\n\n\n\n

Prism Glass Types <\/h2>\n\n\n\n

You’ll find different types of prism glass in binoculars, spotting scopes, and monoculars.<\/p>\n\n\n\n

What is a prism? In terms of binoculars and scopes, a prism is a glass component inside the instrument that corrects the image to the right way up (I wrote about the upside down image <\/a>effect elsewhere).<\/p>\n\n\n\n

In such a context, there are two types of prisms: roof and porro…<\/p>\n\n\n

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\"porro
My article on choosing astronomy binoculars<\/a> explains porro vs roof. <\/figcaption><\/figure><\/div>\n\n\n

When I was looking for gear as a newbie I had no idea what the different glass types meant or what they referred to when reading the specifications. <\/p>\n\n\n\n

Like me, you’ll come across the following describing the optics: <\/p>\n\n\n\n