Автор: kalvados
Дата: 09-12-08 14:53
ptizelov,Георги,asenr,canonio,:ок,явно вложихме малко повече емоции в темата!Извинявам се ако някой се е обидил!Просто цитирах писание от интернет,в което се посочва че ТАКУМАР -ите пожълтяват с времето вследствие на някакъв химикал който е ползван при производството им,а при СУПЕР ТАКУМАР-ите и при 50/1.4 SMC Pentax-M/A/F/FA това го няма Моля погледнете пак текста... The bad news: unfortunately, both versions, and the SMC Pentax 50/1.4
with 52mm filter ring, have an internal element made of material known as "hot glass"
which turns yellowish to brownish with age. The affected lens element contains
thorium, a radioactive rare earth element. Several lens makers including
Pentax, Kodak, Leica, and Canon used this manufacturing technique in the
1940s to early 1960s to lower the index of refraction of specific lens elements.
The yellowing is curable by exposure to ultraviolet or sunlight, as has been
discussed on the Spotmatic Yahoo! Group.The earlier 8-element 50/1.4
Super-Takumar and the various 55/1.8, 55/2.0 and 55/1.9 Takumars do
not turn yellow, nor do the newer 50/1.4 SMC Pentax-M/A/F/FA.
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