Shel,
I figured it was just an awkwardly-phrased thought. Thanks for the
clarification.
Now, to the sentiment: Stratification of lenses aren't really a new
concept. The K-mount Takumars are widely agreed to be "budget"
efforts, with all the shortcomings attendant with the word, are they
not? How long ago did they appear on the market?
Pentax, according to the info I've read, doesn't use plastic
"elements" in their lenses. What they have done, in efforts to
achieve Aspheric shapes, is to mould a =surface=, which is then
cemented to a regular glass element. This is because, up to recently,
the technology required to mould the optical glass to such a shape
simply didn't exist, and forming the shapes with regular
glass-forming methods would be too costly. Now the word is that the
ability to mould glass to aspherical shapes is becoming more
feasible, from both the technological and financial standpoints.
What that means, of course, is continued stratification, but also the
ability to build aspherical qualities into more consumer oriented
lenses using the plastic surfaces, and including full-glass
aspherical qualities in the higher ticket items.
As to whether the plastics used in lenses can stand the stress and
strains, better ask a Canon shooter. I was told that the first Canon
lens to incorporate a plastic element was the old FD-mount 50/1.8
that came out with the AE-1, and they have regularly used plastic
elements since. That's a quarter of a century of plastic use, so a
good lens repair tech could tell you if there have been any problems.
Doug
At 5:32 PM -08001/27/01, Shel Belinkoff caused thus to appear:
>Doug Brewer wrote:
>>
>> Shel, you don't really think the old
>> Takumars weren't built to a price point,
>> do you?
>
>Right after I sent that I realized that, although I knew what I
>meant, I could have phrased it better. What I was attempting to
>say is that, in the past, there was only one grade of lens,
>appropriate for amateur and professional alike. Some were more
>or less expensive due to their speed, but essentially all were
>built to the same standard of quality and excellence. Now there
>are consumer grade lenses, lenses for amateurs, and lenses for
>professionals. The quality of construction and the quality of
>the optics differ between the grades of lenses.
>
>--
>Shel Belinkoff
--
Douglas Forrest Brewer
Ashwood Lake Photography
[EMAIL PROTECTED]
http://www.alphoto.com
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