Archived posting to the Leica Users Group, 1997/12/17
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It never actually reaches 0, but mathematically speaking you would say that
the limit of y as x approaches infinity is 0.
Thus, it is possible to be focused on "infinity" even though there is
no number that actually represents this distance. --Marc Turner
- --------------------------------------------------------------
Marc,
The next inevitable question is: When a lens is focused to the infinity
symbol, what distance is it really mechanically focused on? An actual lens
isn't a formula. It must be focused to a particular point in space. That is
the ultimate question as it concerns photographers.
For example, we would like to know at what distance the lens designer invokes
infinity; after, say for a 50mm lens does infinity begin at 500', a 1000',
etc. I would like to know that number. But nobody who should know tells me
what is is. Why? Is it the last number before Infinity marked on the focusing
collar? Or is it an undisclosed number that is arbitrarily assigned the
Infinity symbol?
Once and for all, let's nail this thing to the wall.
Bob