Archived posting to the Leica Users Group, 2010/03/19
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]The long focus lenses with optical units that disconnect for use on visoflex make fantastic 6x6 lenses. I used my 135mm f/4.5 Hektor in this way on my various Bronicas more than I ever shot with it on my M4. I don't think I ever mounted it on the M8, actually. I still have the adapter for the Hektor-Bronica S system if anyone wants it. Phil Forrest On Fri, 19 Mar 2010 17:00:50 -0700 Richard Man <richard at imagecraft.com> wrote: > 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 > > > > >