>From : "Piers Hemy"
Subject : [OM] Re: Tamron 300
Three points Graham (sorry, not quite enough for you, the collective, to
have one each)
Terrestrial 'infinity' - the most distant point to be focused upon - might
only be 500 meters away, or four or five miles away. The longer the lens,
the more apparent the difference between the two 'infinities'
Ambient temperature can affect the critical focusing performance of a lens,
which is more noticeable with a longer lens.
'Beyond infinity' is shorthand for "racking the focusing mount into the
camera body further than the point at which the lens is accurately focused
at infinity" (where the definition of infinity is subjective anyway, asi
indiacted above!). It doesn't mean that there is (or is not) anything
beyond infinty (as defined).
And, as Jim Brokaw has usefully pointed out, maybe you don't want to focus
at infinty anyway! Oops, four points.
Piers
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Thanks Piers I think we got it now :-)
Graham
www.geebeephoto.com
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