Archived posting to the Leica Users Group, 2008/04/20
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]I wonder if someone (maybe Tarek, Len) would suggest a very simple formal test setup (the most basic) for this purpose, to run a few lenses thru...? my own testing is at best rudiimentary, as I test by actiually shooting, but I'd like to do a limited amount of formal testing, thanks, Steve On Apr 20, 2008, at 7:17 AM, Tarek Charara wrote: > I must be lucky... All of my lenses did fine wide open with the M8... > > All the best from the south of France! > > Tarek > > ------------------------------------------------- > Tarek Charara > <http://www.pix-that-stimulate.com> > > NO ARCHIVE > > > Le 20 avr. 08 ? 16:15, Steve Barbour a ?crit : > >> >> On Apr 20, 2008, at 6:46 AM, Leonard Taupier wrote: >> >>> This is a very interesting issue. I don't know if anybody has >>> mentioned what happens to the depth of field of the Noctilux, or >>> any other lens, in a Leica film camera versus the M8 digital >>> camera. It seems that nobody complains about the focus on a film >>> body but all kinds of complaints on the M8, especially the >>> Noctilux, Summilux Asph and the 75mm Summilux. Is there a >>> difference? Yup, there sure is. I tested 16 leica lenses for depth >>> of field at a distance of 8 feet. I tested 13 of the lenses with >>> film using a .85 MP and compared the results to those taken with >>> an M8 and a 1.25 Leica magnifier. >>> >>> In every case the DOF shifts away from the camera with the M8. In >>> other words the lens appears to back focus. The worse lens for >>> this shift is the Noctilux. But even on a film camera it is barely >>> in focus. The typical back focus shift of any 50mm Leica lens is >>> about 4 to 5 inches at 8 feet with the M8. The backward shift of >>> the Noctilux is between 8 and 9 inches. This puts the focused >>> point of the rangefinder outside the depth of field of the lens. >>> The other thing I noticed is the DOF is better centered on the >>> older LTM lenses then on the newer lenses. I don't know if this is >>> a quality control problem now or if the focus point test has >>> changed. I tested 7 LTM lenses, the Xenon, Summarit, Summitar, >>> Summicron Coll, 50 Elmar RS, 90 Elmar and 135 Hektor. The focus >>> point nicely stayed within the DOF on both cameras. Of the M >>> lenses the best is the 1st 50mm Summicron rigid version followed >>> by the current 50mm Summicron. >>> >>> I verified my results with a second M8. The MP body is one year >>> old and purchased new. I also sent my Noctilux and 75mm Summilux >>> to DAG for focus adjustment even though the lens is still in >>> warranty. I'm also shooting more with film these days. >> >> hi Len, >> >> is it appropriate to send a Noctilux to DAG for focus adjustment, >> without the body... >> >> does that work out OK? >> >> I agree that with film (bodies) I did fine with the Noctilux wide >> open, with the M8 much less so... >> >> Steve >> >> >>> >>> >>> Len >>> >>> >>> >>> _______________________________________________ >>> Leica Users Group. >>> See http://leica-users.org/mailman/listinfo/lug for more information >> >> best, Steve >> >> >> "I never wanted to be famous" >> http://www.blurb.com/bookstore/detail/186890 >> >> >> _______________________________________________ >> 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 best, Steve "I never wanted to be famous" http://www.blurb.com/bookstore/detail/186890