When looking at a bird (Corvis Cornix?) on a tree against a white sky through my Leica Binos today, which are 7x42 Ultravid HD, I realised the bino view was about 2/3 brighter than the direct view.
From there I expect that 7x42 or 8x42 when adopted was historically a lens dimensioning where with older coatings and prism treatments one would have a roughly similarly bright image through a set of binos and direct view.
Today, coatings have got much better, and so if the top bino designs can do 2/3 of a stop better than daylight in 8x42, then similar designs and glass will do roughly equivalent brightness in 8x32.
Which is why people can't be bothered to drag around the 8x42 anymore - in strong sunlight they can dazzle -try the Noctivids to see what I mean- and after dusk they don't really provide a huge advantage. 8x32 on the other hand provide daylight-equivalent brightness at a much smaller size and weight point, at least when they are made by the top brands.
Edmund
BTW. The problem with getting binocular advice from a bird forum is one gets the bird bug. That's now my 3d bird. Boohoo.
From there I expect that 7x42 or 8x42 when adopted was historically a lens dimensioning where with older coatings and prism treatments one would have a roughly similarly bright image through a set of binos and direct view.
Today, coatings have got much better, and so if the top bino designs can do 2/3 of a stop better than daylight in 8x42, then similar designs and glass will do roughly equivalent brightness in 8x32.
Which is why people can't be bothered to drag around the 8x42 anymore - in strong sunlight they can dazzle -try the Noctivids to see what I mean- and after dusk they don't really provide a huge advantage. 8x32 on the other hand provide daylight-equivalent brightness at a much smaller size and weight point, at least when they are made by the top brands.
Edmund
BTW. The problem with getting binocular advice from a bird forum is one gets the bird bug. That's now my 3d bird. Boohoo.
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