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luckis11
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luckis11 said:There's blurness behind the lens except a particular distance behind the lens. This means that there's blurness in front of the lens, yes or no? And, why yes, or why no? Obviously no because seeing without an (outside the eye) lens, there's no blureness, but we need a lens to see and to photograph, so...?
DaveC426913 said:Inasmuch as, if you placed an imaging plane there, it would not produce a focused image, yes. Because an image can only form when the rays falling on point X on the imaging plane all came from point X' in the scene (and no rays from points Y' or other - do). Nowhere does this occur except at the focus of the lens. If too many rays from disparate parts of the image fall on a given image point, that point will not decipherably represent the image.
But if this is so, then in these photographs:
http://en.wikipedia.org/wiki/Bubble_chamber
http://en.wikipedia.org/wiki/Cloud_chamber
the "particle track - line of bubbles" shouldn't be able to be photographed so defined, but blureness should be photographed instead, since-if no lens was used! Correct?
Was a lens used?From the most detailed discriptions of the experimental apparatuses, it seems that no lens was used, but actually in all such descriptions it is not clear if lens was used or not.
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