Archived posting to the Leica Users Group, 2001/01/08
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Martin, It's not just Leica that would wish to claim superior light transmission for their lenses, so the reality is that maybe Leitz might have a fifth of a stop over some lenses and maybe 2/3rds of a stop over the worse (and maybe lose out to some of the better other lenses, especially if its an old and dirty Leitz lens), this is guessing, not taken from measurements. But the latitude of film and processing means that if we need to be critical we fine tune our working processes. If we aren't critical we say, 'Ah shucks', that's another one down to experience and put the slight difference be down to our technique ... Jem - -----Original Message----- From: Martin Howard [SMTP:howard.390@osu.edu] Jem Kime jotted down the following: > As the film industry noted many years ago, F stops are only theoretical values > of light transmission not the true values actually obtained. For this reason > the professional cine industry works to T stops, (standing for True). I was > often told in my youth by my father that a Leitz lens of F2.8 would equal a > lesser lens of F2, at that time I didn't understand but can appreciate what he > was trying to say now. Then how come incident light meters work with Leica cameras and do not result in overexposure? M. - -- Martin Howard | Visiting Scholar, CSEL, OSU | Shit happens. email: howard.390@osu.edu | www: http://mvhoward.i.am/ +---------------------------------------