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Forum: General Photography
04-20-2018, 11:03 AM
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I guess I should have been clearer, but yes you are misunderstanding.
I am mainly wondering from the point of design I guess. Why go for f4.5 vs f2.8
Thank you
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Forum: General Photography
04-20-2018, 10:06 AM
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Hi
I'm curious to hear whether anyone hear can explain this one to me.
Aperture is usually given as proportion of focal length and as such it seems rather obvious why telephoto lenses would have smaller maximum aperture numbers, as 400mm lens would have to have 142mm wide aperture at f2.8, 300mm would be 107mm at f2.8 and so forth (even though I suppose lenses with this focal lengths and apertures may exist)
But why would wide angle and ultra-wide angle lenses (8mm to 18mm) be limited to f4 or f4.5 by design as these lenses have usually body diameters that are more than 10-fold the size ofthe maximum aperture, even at f2.8 .
interested to hear from those who know.
regards
K
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