[MF3D.FORUM:811] Re: Viewer magnification vs negative enlargement

["don lopp" <dlopp@xxxxxxxxxxxxxxx>]

Not exactly correct as the Viewing area is normally masked down to 2inches
by 2 inches or less but the answer is good minus my nitpicking Don.
----- Original Message -----
From: "David Lee" <koganlee@xxxxxxxxxxxxx>
To: "Medium Format 3D Photography" <MF3D.Forum@xxxxxxxxxxxxx>
Sent: Monday, June 19, 2000 9:44 PM
Subject: [MF3D.FORUM:800] Re: Viewer magnification vs negative enlargement


>
>
>
> > When we say that our 80mm FL MF viewing lenses are a 3x
> > magnification, how does that compare to negative enlargement
> > calculations?   Are enlargement and magnification measured
> > the same way?  Is viewing a 2-1/4" chrome with 80mm FL
> > lenses roughly equivalent to viewing a 6-3/4" print? (In
> > terms of evaluating sharpness, for example.)  Or is it
> > like viewing a 9" print (1+ method)?  Or something totally
> > different?
> >
> > Paul Talbot
> >
>
> Depends on how far away from the print you are when viewing it. Simply
> divide the size of the print (say 10") by the size of the negative (2.25")
> equals 4. Multiply 4 by the focal length of the taking lens (say 3")
equals
> a viewing distance of 12" for that particular size print. In 2D parlance
> this is called "the proper viewing distance" and in 3D it is orthostereo.
> You can calculate the proper viewing distance for any print using this
> method and it will be the equivalent of viewing in a viewer with a focal
> length the same as the taking lens.
>
> David Lee
>