Discussion in 'Photography Beginners' Forum' started by gundy74, Jan 3, 2007.
i was just wondering why the aperture on zoom lenses is reduced when zoomed.
The actual aperture isn't really reduced...but the F number is. The F number is a ratio of the focal length and the diameter of the aperture. So as you increase the focal length but don't increase the size of the aperture...then the F number changes.
It's a lot more expensive to make and design a lens that allows the aperture to increase in size as it zooms out...so for cheaper lenses...they make the aperture able to open to a certain size...and that's the maximum for both the short end and the long end of the zoom.
Does that make sense?
yes and thank you
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