[Leica] Image circle

[richard at imagecraft.com (Richard Man)]

Well, covering 24x36 is without a doubt, the question is, how much more does
it cover :-)

For example, I know 50/2 Summicron R covers 80% or so of the 645 format!!

On Fri, Mar 19, 2010 at 4:35 PM, Geoff Hopkinson <hopsternew at 
gmail.com>wrote:

> Yes! It is just a better corrected circle. ;-)
> FWIW all of the M lenses produce an image circle sufficient to cover all of
> the 24x36 mm rectangle and Peter Karbe (Optics department head at Solms)
> recently said that the S system lenses provide an image circle sufficient
> for that camera's 30x45 mm sensor (but no larger)
>
> Cheers
> Geoff
> http://www.pbase.com/hoppyman
>
>
> On 20 March 2010 08:40, philippe.amard <philippe.amard at sfr.fr> wrote:
>
> > Is the circle really a circle when using ASPH lenses?
> >
> > Sure?
> >
> > Phx
> >
> >
> >
> > Le 19 mars 10 ? 23:34, Mark Rabiner a ?crit :
> >
> >
> >> Richard,
> >>>
> >>> The size of a lens image circle is not absolute but depends on your
> >>> criteria. Most lenses are sharp and relatively distortionless in the
> >>> center of the image. Quality and illumination fall off as you move
> >>> away from the axis. You have reached the edge of the lens image circle
> >>> when the image quality no longer meets your photographic requirements.
> >>> That being said, the easiest way to determine the approximate size of
> >>> the image circle is to hold the lens in front of a ground glass. Adjust
> >>> it so that it focuses a distant scene and simply measure the
> >>> illuminated circle on the ground glass. Most normal lenses have a
> >>> reasonable quality of image in a circle with a diameter approximating
> >>> their focal
> >>> length. Symmetrical lens designs tend to have a bigger image circle and
> >>> are frequently used for wide angle lenses.
> >>> Larry Z
> >>>
> >>>
> >>
> >> And your image circle gets better when you work closer.
> >> That you learn from view camera work.
> >>
> >> [Rabs]
> >> Mark William Rabiner
> >>
> >>
> >>
> >>
> >>
> >> _______________________________________________
> >> Leica Users Group.
> >> See http://leica-users.org/mailman/listinfo/lug for more information
> >>
> >>
> >
> >
> > _______________________________________________
> > Leica Users Group.
> > See http://leica-users.org/mailman/listinfo/lug for more information
> >
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
>



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