On Thu, 1 Feb 2001 10:07:02 -0600 "William Robb" <[EMAIL PROTECTED]>
writes:
>Har, they updated the old 45mm GN lens, which was also a Tessar
>type (BTW, aren't just about all lenses in the 28 to 85mm focal
>range Tessar types?).
There may not be an exact definition of a Tessar lens. One optics text
does call many of these "Tessar form" lenses, but the classic Tessar lens
is a 4-element lens, with a max aperture of f/2.8 or f/3.5. An example
of a lens that is not a classic Tessar type is the Pentax 40mm f/2.8
lens. The Pentax lens is a 5-element, 4-group design while the Nikkor
and Zeiss Tessar (Contax mount) 45mm f/2.8 lenses are 4-element, 3-group
designs. Once you get beyond f/2.8 or wider than 40mm (for 35mm
cameras), lens designs tend to be very different from classic Tessar
lenses.
The real interesting thing on the web site was not the lens, but a link
to the new Nikon FM3A camera. A completely manual camera with batteries
required only for auto exposure ( like the LX). I think Nikon will sell
a lot of these.
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