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Message: <blockquote data-quote="Red_Shoulder" data-source="post: 3200103" data-attributes="member: 130635">I think the largest view I've heard of in  binoculars is 26° or something over 20° on a low power 2.5x pair. Not enough for birding,  really,  imo.Old 7x35's got 11°+, some Swift and tasco, others. Steve was saying 116, 118, 400 Tasco. I have some Montgomery Wards and JC Penney that claim to be that wide. But I don't think the width of field listed on binoculars is that accurate. I don't think you could calculate it realistically,  seems like you would have to know a lot about optics,  maybe the focal lengths of the components,  etc. Not sure how you would calculate field of view. I estimate with stars. I got 2.77° for Orion's belt, but that's setting, Big Dipper might be good.  I took calipers to a star map trying to figure out distance.  Taki's 8.5 star map is good. Free programs like Stellarium & carte du ciel could possibly do the calculations for you,  not sure</blockquote>