Archived posting to the Leica Users Group, 2000/11/10

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Subject: Re: [Leica] Re: DOF
From: Mark Rabiner <mark@rabiner.cncoffice.com>
Date: Fri, 10 Nov 2000 11:50:00 -0800
References: <20001110131912.26946.qmail@web4405.mail.yahoo.com>

Brougham wrote:
> 
> Mark Rabiner <mark@rabiner.cncoffice.com> wrote:
> 
> > If you fill the top to bottom of the chair with a 28mm it should give
> > you just as much front to back dof as when you pull way back across
> > the street and fill the chair top to bottom with a 90mm lens.
> >
> > But it doesn't'.
> 
> Why should it be the same?  DOF is based on aperture and distance from
> the lens.
> 
> The larger the aperture opening, the larger the circles of confusion.
> Less DOF.
> 
> The further from the lens, the less relative change in the size of the
> circles of confusion as you move the same absolute distance.  More
> DOF.
> 
I think it's based on magnification and aperture.
Mark rabiner

In reply to: Message from Brougham <brougham3@yahoo.com> ([Leica] Re: DOF)