General Lens ZOOM question....

On 26 Jun 2004 07:29:36 -0700, (Giorgio
Preddio) wrote:

"Tony Spadaro" wrote in message .com...

In general there is a 10% fudge factor on lenses. (ie anything between
270 and 330 would be a 300, but believe me now one ever called a 325mm lens
300. It could be that for these "super" zooms, a lot of the range has more
to do with advertising than fact. I would say that if you need a 1.4 TC to
get 300mms out of it, it's a good lens to send back.

Surely 300mm is 300mm no matter what make of lens..... ?

You will find that the Sigma lenses are the most accurate in terms of
focal length accuracy. I conducted some very thorough testing in this
area last year. My photography students learned quite a bit from the
study. Unfortunately, my sponsors prevented me from publishing the
results due to corporate politics.


Hogwash.


GK

George is, of course, lying. He owns no camera, has no students, has never
tested anything, and is full of shirt.

--
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"Giorgio Preddio" wrote in message
om...
"Tony Spadaro" wrote in message
.com...

In general there is a 10% fudge factor on lenses. (ie anything between
270 and 330 would be a 300, but believe me now one ever called a 325mm
lens
300. It could be that for these "super" zooms, a lot of the range has
more
to do with advertising than fact. I would say that if you need a 1.4 TC
to
get 300mms out of it, it's a good lens to send back.

Surely 300mm is 300mm no matter what make of lens..... ?

You will find that the Sigma lenses are the most accurate in terms of
focal length accuracy. I conducted some very thorough testing in this
area last year. My photography students learned quite a bit from the
study. Unfortunately, my sponsors prevented me from publishing the
results due to corporate politics.