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Old 30-03-2016, 12:48 PM
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barx1963 (Malcolm)
Bright the hawk's flight

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Join Date: Nov 2008
Location: Mt Duneed Vic
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Quote:
Originally Posted by Finite View Post
I also saw written recently that the way f ratio works in a telescope is different to how it works in a camera. I'll have to look that one up, as I'm pretty sure it's the same principle.? Both are effectively lenses.
I could be wrong, but my understanding is that they are exactly the same, focal length divided by aperture. The main difference is that in most cases, the f ratio is fixed in a telescope, while it is variable in a camera lense.
There is a discussion here https://en.wikipedia.org/wiki/F-number

Malcolm
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