Archived posting to the Leica Users Group, 2012/06/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Nice. Thanks, but I am not sure what it exactly means. I wish I had some exposure test taken with my Canon XTi, but I deleted all those tests. Maybe someone with Leica glass on a Canon could post some data to see the difference. As I said, I remember making up to 4 stops of underexposure to make things work. It was much worse than my Nikon D7000. The Olympus does not look that bad. Aram -------------------------------------------------- From: "Jim Nichols" <jhnichols at lighttube.net> Sent: Sunday, June 10, 2012 1:26 PM To: "Leica Users Group" <lug at leica-users.org> Subject: Re: [Leica] Using M (and R) glass on a Sony NEX-7 Now DATA > I finally got your data plotted on a log scale. > http://gallery.leica-users.org/v/OldNick/image003+copy.tif.html > Jim Nichols > Tullahoma, TN USA > ----- Original Message ----- > From: "Aram Langhans" <leica_r8 at hotmail.com> > To: "Leica Users Group" <lug at leica-users.org> > Sent: Sunday, June 10, 2012 11:00 AM > Subject: Re: [Leica] Using M (and R) glass on a Sony NEX-7 Now DATA > > >> That's what I mean, too, except the Nikon D7000 and D300 does not behave >> the same as Howard's D700. >> >> Can anyone make sense of these data? >> >> Lens 1 is Nikon 50/1.2 >> Lens 2 is Leica-R 50/2 Summicron >> Lens 3a is Leica-r 35-70/4 shot at 35mm >> Lens 3b is same lens shot at 50mm >> Lens 3c is same lens shot at 70mm >> >> Subject, an evenly lit patch of grass in my front lawn. Went through the >> f-stops twice for each lens to check consistency. Same reading each >> time. >> >> >> f-stop Lens 1 Lens 2 Lens 3a Lens 3b >> Lens 3c >> 2 1600 1600 >> 2.8 800 1000 >> 4 400 400 640 500 640 >> 5.6 200 100 160 200 320 >> 8 100 40 50 60 100 >> 11 50 25 30 30 50 >> 16 25 15 20 20 20 >> >> As you can see, the Nikon behaves as it should be and meters correctly >> through the f-stop range, halving the shutter speed for each smaller >> f-stop. >> The Leica lenses do not and progressively overexpose as you stop the lens >> down. I am surprised that the zoom did not meter correctly wide open. >> In my field experience, wide open is not a problem, and the overexposure >> only starts to show up as you stop down. >> >> I am also surprised that the overexposure is limited to about one stop. >> In my field experience I sometimes have to compensate about 2 stops. >> >> That said, there is about a one stop overexposure in this test while my >> Canon, when I had it, would overexpose about 4 stops if you stopped down >> enough. >> >> >> >> >> -------------------------------------------------- >> From: "H&E Cummer" <cummer at netvigator.com> >> Sent: Sunday, June 10, 2012 6:04 AM >> To: <lug at leica-users.org> >> Subject: [Leica] Using M (and R) glass on a Sony NEX-7 >> >>> >>> Date: Sat, 9 Jun 2012 16:13:38 -0600 >>> From: Bill Nelsch <photobynelsch at gmail.com> >>> Subject: Re: [Leica] Using M (and R) glass on a Sony NEX-7 >>> To: Leica Users Group <lug at leica-users.org> >>> >>> I have a stupid question: When you say the D7000 is "linear" - what >>> does >>> that mean actually? How does that affect the exposure? >>> >>> Bill in Denver >>> >>> Hi Bill, >>> By linear I mean that as you close down the lens aperture the shutter >>> speed drops by an equal amount in terms of light transmission >>> If you are at f5.6 and 1/500 and then close down to f8.0 the shutter >>> speed adjusts to 1/250 - to f11.0 the shutter speed drops to 1/125 >>> keeping the light transmission the same. That's what happens on the >>> Nikon. On the Canon without Canon lenses that "talk" to the body >>> as you close down a Leica R lens mounted with an adapter that isn't >>> chipped the shutter speeds drift away from the above response and you >>> get more and more exposure variation. >>> Hope this clarifies my point for you. >>> Cheers >>> Howard >>> >>> >>> >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information >> >> > > > >