Archived posting to the Leica Users Group, 2020/02/19
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]This is a review that includes a cut-away of the MATE optics here: https://www.stevehuffphoto.com/2010/11/11/the-leica-mate-lens-review-medium-angle-tri-elmar-by-ashwin-rao/ Paul www.PaulRoark.com On Wed, Feb 19, 2020 at 12:43 PM Ken Iisaka <ken at iisaka.com> wrote: > I think there is more to it. > > Tri-Elmar 28-50 is basically a zoom lens with two groups: a positive > focusing lens group closer to the film, and a negative group up front. The > distance between them is what determines the effective focal length of the > lens. > > To have a negative group up front and having a positive group in the back > is the definition of a retrofocus design. > > At 28mm, the centre of the lens is well ahead of the focal plane, certainly > further than 28mm. This indicates that it is effectively a retro focus > lens. At 50mm, it is less so. > > On Wed, 19 Feb 2020 at 11:21, Frank Filippone via LUG <lug at > leica-users.org > > > wrote: > > > It is not considered a retrofocus design. > > > > That's it folks.... Final answer > > > > Frank Filippone > > BMWRed735i at gmail.com > > > > _______________________________________________ > > Leica Users Group. > > See http://leica-users.org/mailman/listinfo/lug for more information > > > > > -- > Ken Iisaka > first name at last name dot org or com > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >