Tagged Questions
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0answers
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Digital video cameras optical zoom vs lenses [migrated]
If you read at digital video cameras specifications, you will probably read that camera has 20x optical zoom or even greater.
If you compare this camera with my Nikor 18-200 lens, the lens itself is ...
19
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3answers
1k views
When you zoom in with a lens on an SLR why does the lens go in then out?
I guess this is more a question of optics than photography but I just got an SLR with a basic 18-55 lens. I noticed that when going from 18 to 55 or 55 to 18 the lens physically comes back in and ...
9
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2answers
1k views
Why do zoom lenses and compact cameras have varied maximum aperture across the zoom range?
Why does a camera's maximum (allowed) aperture get smaller when you increase its zoom?
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4answers
3k views
How can a lens like a 18-55mm have more than one focal length?
How can a lens have a range of focal lengths? Shouldn't it be a single number?
Isn't focal length supposed to be fixed for a lens of a particular shape and geometry?
What am I missing?
How many ...
