Archived posting to the Leica Users Group, 2001/02/09

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Subject: Re: [Leica] Re: DOF -Optical vs Apparent -- Part 1
From: "R. Saylor" <rlsaylor@ix.netcom.com>
Date: Sat, 10 Feb 2001 02:38:05 -0500
References: <B6A9F7DB.5AAF%howard.390@osu.edu>

What amuses me is that this whole issue is more over semantics 
than the real issue.  Theoretical DOF is a mathematical/physical 
determination based on a perfect lens.  What appears to be "in 
focus" or "out of focus" (in a real image) will obviously depend on 
the relative absence or presence of lens aberrations (and maybe 
something else which I'm forgetting).  To take an extreme example, 
the effective "DOF" of a disposable camera can be zero or even 
negative, in that the COC is unacceptably large even in the plane of 
focus.

My apologies to Mr. B. D. Colen (a.k.a. Dr. Black Tape) for further 
extending this absurd thread.

Richard

In reply to: Message from Martin Howard <howard.390@osu.edu> (Re: [Leica] Re: DOF -Optical vs Apparent -- Part 1)