Macro on dSLR

On Tue, 01 May 2007 17:43:25 GMT, "Jürgen Exner"
<jurgenex DeleteThis @hotmail.com> wrote:

>I'm a bit confused and would appreciate some clarification.
>
>For the sake of argument let's say I have a 60mm macro lens with a minimal
>focus distance of 20cm and a 1:1 magnification. Because of the cropped
>sensor (factor 1.5) this lens has a viewing angle like a 90mm lens would
>have on a film camera. So far, so good.
>
>Now, the minimal focus distance should not change because that distance has
>nothing do to with the sensor. So because of the 50% 'virtual' tele
>effectively this lens should have an even better magnification which would
>correspond to a 1:1.5 on a film camera.

Yeah, seems that way. Isn't it wonderful when you can throw away more
than half the area of the image and end up gaining?

Of course you could do the same thing with 35mm... crop the neg or
slide to 24x16mm; and that fills the frame more fully with small
subjects. So the subject gains size, at least compared to the frame.
But it loses definition.

As poster dennis pointed out, magnification is defined as the ratio of
subject:image sizes, so the max magnification is still 1:1. That's
just optics.

But generally, going to the smaller format makes it easier to do
close-up work. You get more depth of field too. Conversely, the
photographers of yore who shot 4x5 inch or 8x10 inch format had a
harder time of it. No wonder Edward Weston got so much credit for his
pictures of peppers. It also explains why he preferred nudes.

It gets confusing if you are rooted to the old 35mm ways and are
trying to compare. It's better if you can get used to the new format.

KS
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