Archived posting to the Leica Users Group, 2015/11/17
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Thanks for the tip, George, especially the reminder to test at distances other than infinity. ?howard > On Nov 16, 2015, at 11:08 PM, George Lottermoser <george.imagist at > icloud.com> wrote: > > Digital allows us to check things like IR focus quite easily. > > When I decided to dedicate the M8 + 40 mm Summicron to IR Photography. > I put the rig on a tripod; > focused with the range finder on ROCKS that could not move; > shifted the focus distance to each aperture to the right (up to 5.6). > > I did this for varying distances from around 3 feet out to infinity. > > When I looked at the images on the computer > it became very clear that shifting the focus to the f:4 mark on the 40 mm > Summicron > provide maximum sharpness at the viable working apertures, from f:2 > through f:8. > Results have proven very consistent. > > Variances can generally be attributed to various combinations of camera > and/or subject movement. > > I'll be ordering a 092 soon; > and I'll run a similar group of test photographs with the new filter. > > a note off the iPad, George > > On Nov 16, 2015, at 8:45 PM, Howard Ritter <hlritter at bex.net> wrote: > >> Any thoughts? > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information