Re: Newbee Question Regarding Lens Magnification

Sidney Friedman <counsel2@xxxxxxxxxxxxx> wrote:

> I have two AF Nikon zoom lenses for my Nikon D70s, 18mm-70mm and 70mm-300mm.
> What exactly do these numbers represent?
>
> For example, does 300mm mean a magnification of 300 times? Does 70mm mean
> only 70 x magnification? Or....

It's the lens focal length -- technically the distance from the optical
center of the lens to the image plane (sensor). It is not the physical
distance, because this is modified by the lens elements; conceptually,
it is what the physical distance *would* be if there were no lenses at
all, that is, a pinhole "lens" at that distance would project an image
of that size.

The relation to magnification is direct; 70mm is 2x magnification over
35mm, for example.

--
Jeremy | jeremy@xxxxxxxxxxx
.

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