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Konstabel
01-22-2009, 03:42 PM
How does the f-stop vary when using a zoom lens?

ex:18-55 f3.5-5.6
Does that mean the f-stop is 3.5 at 18mm zoom and 5.6 at 55mm?

tim11
01-22-2009, 03:50 PM
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Does that mean the f-stop is 3.5 at 18mm zoom and 5.6 at 55mm?

Yes. And everything else in between.

David Metsky
01-22-2009, 05:33 PM
ex:18-55 f3.5-5.6
Does that mean the f-stop is 3.5 at 18mm zoom and 5.6 at 55mm?
It means the maximum f/stop at 18mm is 3.5 and at 55mm it's 5.6.

D Thompson
01-22-2009, 06:51 PM
Yes. And everything else in between.


It means the maximum f/stop at 18mm is 3.5 and at 55mm it's 5.6.
Unless you are Razr! :rolleyes:

Konstabel
01-23-2009, 12:25 AM
So I cannot manually set the f-stop to say 3.5 at 55mm focus and vice versa?

TheWengler
01-23-2009, 12:41 AM
You can set it to 5.6 at 18mm, but not the other way around. It's the MAX aperture.

tim11
01-23-2009, 02:30 AM
Unless you are Razr! :rolleyes:
Yeah I rememeber the thread. :D

tim11
01-23-2009, 02:36 AM
F/5.6 is MAX aperture at full zoom.
F/3.5 is MAX aperture at wide. You can also use smaller aperture (larger number) at wide to whatever the smallest aperture of the lens; normally F/22.
At full zoom the widest Aperture is F/5.6 and impossible to set it to F/3.5, but you can use any smaller apertures possible offered by that lens.
I hope that's clear.