Archived posting to the Leica Users Group, 2012/06/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search];~))) Jim Nichols Tullahoma, TN USA ----- Original Message ----- From: "Nathan Wajsman" <photo at frozenlight.eu> To: "Leica Users Group" <lug at leica-users.org> Sent: Sunday, June 10, 2012 3:33 PM Subject: Re: [Leica] Using M (and R) glass on a Sony NEX-7 Now DATA > Guys, how about taking some pictures and checking if they look nice? > > Cheers, > Nathan > > Nathan Wajsman > Alicante, Spain > http://www.frozenlight.eu > http://www.greatpix.eu > http://www.nathanfoto.com > PICTURE OF THE WEEK: http://www.fotocycle.dk/paws > Blog: http://nathansmusings.wordpress.com/ > > > YNWA > > > > On Jun 10, 2012, at 7:06 PM, Jim Nichols wrote: > >> Aram, >> >> I tried putting your table of data into Excel, and plotting it. When I >> saved it as a tiff file, the scales were stripped off. However, with >> shutter speed as the vertical scale, and f-stop as the horizontal scale, >> you can see the variations. There are definitely some spreads in the >> data, but it is hard to say whether it is just hardware variations or >> some sort of correction that is applied to the Nikon inputs. >> >> http://gallery.leica-users.org/v/OldNick/image001+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 >>> >> >> >> >> _______________________________________________ >> 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 > >