Each element of a 'single coated' lens may have a single coating of
different thickness than each of the other elements of the lens, so each
element surface may reflect a different hue. I think this would be to keep
the color balance of the lens neutral.
Multi-coating refers to the presence more than one layer on an element
surface in an attempt to prevent reflections at that surface across a
broader range of wavelengths than is possible with a single coating.
The tricky part is that I'm almost certain that Zuiko coating formulas have
changed more than once - i.e. even after they started multi-coating lenses,
the formulations continued to evolve with time. That is why you can have two
otherwize identical multi-coated Zuiko lenses in your hand, and observe very
different patterns of color reflection within them.
However, the presence or absence of a green reflection somewhere within does
seem to demarcate the 'single-coated' line from the 'multi-coated' line with
some reliability.
Chip Stratton
cstrat@xxxxxxxxx
>
> I'm definitely outta my element (pun intended) where Zuikoatings are
> concerned, but what Larry says kinda makes sense. If you see two
> distinctly
> different hues reflected - rose (I guess that's what I called purple) and
> yellow - wouldn't that qualify as multicoating? Maybe not by
> contemporary
> standards, but duocoating at least. I have an older generic T-mount lens
> that's definitely SC and reflects only yellow.
>
>>
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