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Sigma highlights another problem with plastics, thermal change
On 17/06/2012 3:44 a.m., RichA wrote:
Heat expansion and contraction, which effects optical performance. So they've introduced something else to compensate for it. Because aluminum and magnesium don't suffer nearly as much thermally-related shape changes as plastic, older lenses and new high-end principally metal lenses do not have the problem. http://www.dpreview.com/news/2012/06...superzoom-lens Thom Hogan sums it up nicely in his website: "Of course, if they didn't use black they might not absorb so much heat in the first place" |
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Sigma highlights another problem with plastics, thermal change
On 2012-06-18 19:22 , Me wrote:
http://www.dpreview.com/news/2012/06...superzoom-lens Thom Hogan sums it up nicely in his website: "Of course, if they didn't use black they might not absorb so much heat in the first place" This goes back to a discussion (in rpe35mm) from long ago. Large lenses should be white. OTOH, Nikon don't seem to agree and we don't hear much of the issue with their lenses. -- "Civilization is the limitless multiplication of unnecessary necessities." -Samuel Clemens. |
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