Sigma highlights another problem with plastics, thermal change
In article
,
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.
Sigma's biggest problem is their lying about the crappy technology used
in their overpriced, mediocre equipment.
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