Archived posting to the Leica Users Group, 2001/02/08

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Subject: Re: [Leica] Re: DOF
From: "Rob Heyman" <rheyman@bigpond.net.au>
Date: Thu, 8 Feb 2001 23:47:06 +1000
References: <B6A739C2.E0DE%jbcollier@home.com> <3A81FC21.489B069@rabiner.cncoffice.com>

It would only be noticeable if the viewing distance did not change. The
accepted viewing distance for a print is 1.5 times the diagonal. This allows
the human eye to see the entire image without "scanning". If we apply this
to an 10x8 the viewing distance is just under 13". To view a 60"x40" from
the same neg we should stand at around 80". In both cases our eye will see
the same amount of detail  and the same amount of grain. DOF or even
apparent DOF does not change. If we view a large print from a lesser
distance, we are NOT looking at the picture, we are looking at other less
important or irrelevant stuff . Top pictures are not known for their DOF or
their lack of grain or the amount of magnification the negative underwent.
The PICTURE is of utmost importance.

I am sure that some of you learned gentlemen will correct me if I am wrong.

Rob H


> In a huge print or the edges of DOF are going to be more noticeable.
> The more magnification the print goes though the more something that was
> "slightly soft but no big deal"
> In a small print and magnification
> does become "A BIG DEAL."
> in a large print  of large magnification.
> As a 30x40" from a 35mm neg is a 30x magnification
> and from a 4x5" neg is only a 7.5 magnification.
> You'd be about to get away with more on that large neg.
> Am i wrong on this? I think not.
> But dying to find out.
>
> mark rabiner
>

Replies: Reply from Mark Rabiner <mark@rabiner.cncoffice.com> (Re: [Leica] Re: DOF)
In reply to: Message from John Collier <jbcollier@home.com> (Re: [Leica] Re: DOF)
Message from Mark Rabiner <mark@rabiner.cncoffice.com> (Re: [Leica] Re: DOF)