Archived posting to the Leica Users Group, 2011/11/02
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Remember that the labeled aperture values are all conservative estimates. Depending upon the age, wear, mechanical tolerance and general sloppiness of the labeling, the indicated aperture values could be off by 1/3 stop easily regardless of what lens by any maker. A precision measurement of the opening and a calibration of the true transmission of light by the lens at a particular distance is what will give you the real value. outside of that it's just estimation and estimation has been good enough for the still photography community (for the most part) so it'll continue to do so. Negative film usually doesn't care about 1/3 of a stop in most scenes. Phil Forrest On Wed, 2 Nov 2011 21:12:04 -0700 Quan Tran <quantran101 at gmail.com> wrote: > Hi Mark, > > I think the website meant round to the third. So the different is in > the rounding. > > > On Wed, Nov 2, 2011 at 8:47 PM, Mark Rabiner <mark at rabinergroup.com> > wrote: > > > 2/3's as a decimal is 0.6666. > > 0.7251 - 0.6666 = 0.0585 > > Cant figure out what fraction that would be. > > > > Bottom line a 1.4 is for sure faster than a 1.8 not by an > > incremental amount > > like I thought. > > > > > > > > > > -- > > Mark R. > > > > > > > From: Quan Tran <quantran101 at gmail.com> > > > Reply-To: Leica Users Group <lug at leica-users.org> > > > Date: Wed, 2 Nov 2011 19:36:00 -0700 > > > To: Leica Users Group <lug at leica-users.org> > > > Subject: Re: [Leica] 1.8 vs. 1.4!?!? > > > > > > I found this: http://imaginatorium.org/stuff/stops.htm > > > > > > When I select "precised", it show 0.7251 stops > > > When I select "third", it gave me 2/3 stops. > > > > > > -Quan. > > > > > > On Wed, Nov 2, 2011 at 3:32 PM, Mark Rabiner > > > <mark at rabinergroup.com> > > wrote: > > > > > >> I looked up f 1.8 vs. 1.4 thinking it was between a half and a > > >> quarter > > of a > > >> stop and they are saying its 2/3rds!?!?! Anybody know that > > >> that's true? > > >> > > >> Where is there a photo calculator that tells you these > > >> things?!?!? > > >> > > >> -- > > >> Mark R. > > >> http://gallery.leica-users.org/v/lugalrabs/ > > >> > > >> > > >> > > >> _______________________________________________ > > >> Leica Users Group. > > >> See http://leica-users.org/mailman/listinfo/lug for more > > >> information > > >> > > > > > > > > > > > > -- > > > Quan Tran. > > > blog: http://fluxlux.blogspot.com/ > > > > > > _______________________________________________ > > > 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 > > > > >