I beg to differ. I bought my first zoom vivitar one around 20 years back.
It was a fixed aperture one. Now here in US I bought my new camera systems
and all I am getting are variable aperature ones. In fact, I was initially
surprised to note that aperature varies depending on focal length while
zooming and had to do a little work to understand why it was.
I really miss that constant one.
>From: Todd Stanley <[EMAIL PROTECTED]>
>Reply-To: [EMAIL PROTECTED]
>To: [EMAIL PROTECTED]
>Subject: Re: SMC A 35-105 vs. SMC FA 24-90
>Date: Tue, 26 Jun 2001 10:54:10 -0500
>
>At 05:43 PM 6/25/01 +0200, you wrote:
> >
> >And a different, general question:
> >
> >Why do newer lenses offer inferior aperture values? I thought that new
> >materials and forumlas could permit for brighter lenses?
>
>They do. Zoom lenses have been around for a while, but the constant
>aperture F2.8 such as 80-200mm F2.8 are more recent. But these lenses are
>terribly expensive. The typical SLR buyer would rather pay $150 for a
>slower, variable aperture zoom than $1000 for the fast, F2.8 aperture zoom.
> Also, with newer SLRs, constant aperture zooms are less important. For
>something like manual flash, thyristor flash, or using an external light
>meter, knowing the exact aperture value is important (something not
>possible at all focal lengths on a variable aperture zoom). With better
>built in light meters and TTL flash, a constant aperture zoom is not as
>important to most people.
>
> >
> >In fact I was told that the maximum aperture does not depend on the
> >quality or groups of the lenses, but only on geometry (front lense,
> >length)?
>
>True.
>
> >
> >I do not get this point, since the 35/105 is labeled 'f/3.5' for the full
> >range.
>
>There are a few tricks involved in doing this, that's why these lenses are
>more expensive than variable aperture lenses. One of the tricks is using
>the aperture blades. At the shorter ends the 35-105mm F3.5 lens is
>actually stopped down just a little bit - otherwise it would be something
>like a 35-105mm F3.0-F3.5 lens.
>
>Todd
>-
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