I agree with your comments, including that coatings changed on at least
some SC lenses over their production lifetime. As to the conclusion
based on 'reflection gazing' (Remember waht happened to Narcissus!)
about number of coatings, I'm not so sure. Repeating myself from an
earlier post:
"I've heard lots of people refer to the colors of the reflections, as
though the presence of several different colors shows MC. I don't see
why that would be true. In the case of the design of a lens before MC,
the designer would still want to balance the color response of the lens.
If all surfaces were given the same coating thickness, the lens would
have significantly higher transmittance around the color most effected
by that coating thickness, resulting in a lens with unnatural color
balance. Would not the designer use different thicknesses of coating on
different surfaces to achieve a roughly balanced transmittance across
the visible spectrum? Of course, they must have done so based on the
color characteristics of the lenses produced. Since the color of the
reflection from a SC lens surface is determined by the subtraction of
light around the effective range of the coating thickness, this results
in different colored reflections from different lens surfaces.
It is further true that individual MC coatings are not equally effective
across the whole spectrum. A 2 layer coating can only be even
theoretically fully effective at 3 wavelengths, and possibly only 2 in
many actual applications. So MC lenses continue to have multiple
different colored reflections.
I have gazed into the depths of at least 3 pairs of Zuiko lenses to
compare SC to MC reflections. Although there were some (surprisingly
smaller than I expected) differences in the color of the various sizes
and depths of reflections, the most noticeable difference was the
clearly lower overall brightness of the reflections of the MC lenses,
vs. the SCs."
The earilest SC lenses tend to show overall yellow reflections, while
later ones show a number of different colors. This certainly shows the
results of improvements in coating technology and sophictication, but
not necessarily in the number of coatings. My SC 100/2.8, ser. 110,9xx
shows what seem to be more than one shade of yellow, a pink and a
magenta reflection. The overall brightness of the reflections is clearly
in the SC camp.
Moose
AG Schnozz wrote:
I would suggest that not all silver-nosed 100/2.8s are created
equal. Mine has many more coatings than other single-coated
lenses, but doesn't possess the "green" reflection that
everybody put in to signify that it was a multicoated lens.
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