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From: rcd@opus.UUCP (Dick Dunn)
Newsgroups: net.rec.photo
Subject: Re: Depth of Field previewing
Message-ID: <583@opus.UUCP>
Date: Tue, 10-Jul-84 02:28:52 EDT
Article-I.D.: opus.583
Posted: Tue Jul 10 02:28:52 1984
Date-Received: Fri, 13-Jul-84 03:54:16 EDT
References: <393@tesla.UUCP>
Organization: NBI, Boulder
Lines: 20

>Actually, DOF preview on a camera is more misleading
>than useful, and therefore is dangerous.  DOF is a relative matter that
>depends on degree of enlargement and viewing distance...

There are two sides to the use of DOF preview.  You should be pretty
cautious about assuming that an object will be in relatively sharp focus in
the final print just because it looks in focus in the little viewfinder.
You can probably judge for a 3R print; maybe up to a 5x7 if you're really
lucky, but forget it for large prints (or substantial enlargement due to
heavy cropping).

On the plus side for DOF, you can use the preview to see what happens to a
background you're trying to drop out by leaving it out-of-focus.  This is a
much less stringent judgment - what you're trying to decide is whether the
background of a picture will be sufficiently out of focus that it won't be
distracting - and you want to see the scene when stopped down to judge
this.
-- 
Dick Dunn	{hao,ucbvax,allegra}!nbires!rcd		(303)444-5710 x3086
	...Never attribute to malice what can be explained by stupidity.