Simon Evans wrote:
> Richard Schaetzl wrote:
>
> >> with the
> >> "cut from flat blanks of Schott glass" hype.
> >
> >That's crap, the B+W catalog shows how cyinders are drilled out of the
> >Schott glass and the cylinder are cut into thin discs, polished and
> >coated by B+W.
>
> What I was saying is that B+W are suggesting it is superior to other brands
> because of this fact. Where is the evidence?
I don't meant that your comment was crap, but the idea Schott would
provide "flat blanks". Schott sells only glass, no blanks, other
filter manufactors than B+W use Schott glass as well (Heliopan).
> That it appears in the advert means it is marketing.
> Is optical glass made this way superior to any other?
Some filter maker sell filters made of gel filters placed between two
glass surfaces. This is optical inferior to filters made of coloured
glass. The sandwich construction prevents coating, is most likely not
as flat and the colour will fade with time.
Not all "orange" filter filter the light in the same way. One might be
surprised how different two "81c" filters can be.
B+W and Heliopan inform the customer which Schott glass has been used
so the filter transmission is known. For the convenience of his
customer, Heliopan printed this information in their catalogue. Schott
guaranty that filters with the same glass provide the same colour
rendering.
Hoya is a little bit reluctant to inform consumer about such technical
details, at least in that catalogues I own.
> My comment that such brands were usually more expensive was compared to
> filter manufacturers like Hoya,
One should only compare goods of the same quality, Hoya/Kenko filters
of the same quality as B+W or Heliopan filters are priced at a similar
level. There might be small difference depending on the individual
market, but generally you get what you pay.
Another thing not to forget is that Hoya/Kenko has a wider range of
filters qualities for sale, so one should not compare the price of low
end Hoya with high end B+W filters, but of filters of the same
quality.
Before Hoya started to market their filters under their own brand in
Europe, they were distributed by Hama as Hama-Hoya filters. I have
some of this filters, price was a little below of what B+W had asked,
but quality was far inferior. The filter frame was made of very thin
aluminium and has been easily bend. The blackening of the frame was so
poor, blank aluminium was visible after a short time, the writing on
the frame partial disappeared. Not a good buy. In contrast my B+W
filter of that time are still in a good shape (so far not abused).
> reasons for hefty price tags. I wonder who makes their filters?). Brands
> such as B+W, Schneider, Leica et al have traded for a long time (at least in
> the UK and, I believe, North America) on the idea that their products are
> somehow better because they are German.
Such philo-germanic feelings are surprising. If you have a problem
with "German glass" buy Russian. ;-)
Leica, Schneider and B+W _are_ better than many of their competitors.
Leica and Schneider lenses _regularly_ score higher than many of their
competitors. I dare to say that the average quality of Leica lenses is
higher than that of say N*k*n or C*n*n lenses.
Leica lenses are of better quality even if they are build by their
Japanese competitors. "Stiftung Warentest", an German consumer
protection association, tested in the 80's 70-210mm zooms. That
lenses of Japanese OEM like Minolta, Canon or Pentax fared well and
all scored "good", while third party manufactors couldn't satisfy the
critical tester with the exception of Tamron 70-210mm/3.5 which also
was "good".
The best lens in the test scored "very good", it was the Leica zoom.
Which, at that time, was build and designed by Minolta. So Japanese
manufactors could build excellent lenses if the specs would be tight
enough, at a price: The Leica-Minolta was five times the price of the
Minolta-Minolta. Of course the barrel and all mechanics of the
Leica-Minolta were completely different from the original Minolta
design. Minolta lenses of that time had not a bad build quality but
compared with lens build for Leica the Minolta zoom looked flimsy.
I might add, that "Stiftung Warentest" is considered not to be blinded
by nationalistic prejudices or influenced by advertisers (there are no
advertisers).
Build quality is a factor. Leica use brass-aluminium combinations for
threads like that of the focusing mechnism, because this combination
allows much higher precision. The parts move smooth without much
grease. Most Japanese manufactors use (used) aluminium-aluminium
combinations, but that combination tend to be "sticky". So fitting has
to be more generous and plenty of grease is used.
There is a problem with those "minty" second hand Zuikos that stood
most of the time on the shelf. The grease has "seated" and is no
longer even distributed. While focusing, one can notice an uneven some
times smooth, some times scratchy movement. Were the grease has
disappeared, the aluminium threads move against each other, creating a
lot abrasion. Olympus has coated at least one side of the thread, but
that doesn't help in this situation.
Solution is to move the focusing ring very carefully and slow, so the
grease is redistributed evenly between the thread.
Did I mention that the brass frames of Heliopan filter move so
smooooth into the filter threads of my Zuikos? ;-)
Happy new year
Richard
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