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Old 05-16-2008, 10:21 PM
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sk66 sk66 is offline
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Quote:
Originally Posted by vandergus View Post
The f number is the ratio of the focal length to the diameter of the opening that the light enters through. For example, a 50mm lense at f2 has an opening 25mm across.

To be perfectly clear, there is no difference in f-stop number between different formats (sensor sizes) when it comes to how much light the medium is exposed to. F2 is f2 when it comes to exposure. The 35mm equivalent that dimitrz is referring to is the equivalent depth of field. The depth of field is not a function of just the aperture but also of focal length. The dependence on focal length, typically much smaller in a digicam, to have such a large depth of field.
Thanks for the clarification...I was confused on what the f-stop was in relation to (focal length, not max aperture). I probably new that at one time...
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