Archived posting to the Leica Users Group, 2012/06/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Hi Jayanand, That is all well and good, but the bee may be gone before the second shot can be made. That is why I like to get the first one right. ;~) Jim Nichols Tullahoma, TN USA ----- Original Message ----- From: "Jayanand Govindaraj" <jayanand at gmail.com> To: "Leica Users Group" <lug at leica-users.org> Sent: Sunday, June 10, 2012 10:52 PM Subject: Re: [Leica] Using M (and R) glass on a Sony NEX-7 Now DATA > Why does all this matter? Look at the histogram and adjust! Digital makes > it so easy to get a good exposure.... > Cheers > Jayanand > > On Mon, Jun 11, 2012 at 1:15 AM, Jim Nichols > <jhnichols at lighttube.net>wrote: > >> Aram, >> >> I will add to the confusion. >> >> After plotting your data on the NEX-7, I became curious about my Olympus >> E-1, which is an early professional model. I compared the companion >> lens, >> which was the Olympus 14-54 zoom, to my Summicron-R and my Elmarit-R 60mm >> Macro. By some stroke of luck, I was able to use a log scale for this >> one, >> which helps with the comparison. I have tried to do the same for my >> first >> chart of your data, but can't find that option again. >> >> If the 14-54 lens, which communicates with the camera, is taken as the >> "standard", then my Elmarit-60 is not too far off this line. However, my >> sample of the Summacron-R 50mm shows that it departs from the norm, >> particularly above f/8. In your data, this departure starts at about >> f/5.6. After seeing this, I would not choose the Summicron-R as a measure >> of performance for a Leica prime lens. My Elmarit-R 60 looks much >> better. >> >> In looking at your data for the Leica zoom, I begin to wonder if there >> are >> too many compromises in zoom lens design. I did not pursue recording the >> 14-54 data at other focal lengths. >> >> 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<http://leica-users.org/mailman/listinfo/lug>for >>> >>> more information >>> >>> >>> >> >> >> ______________________________**_________________ >> Leica Users Group. >> See >> http://leica-users.org/**mailman/listinfo/lug<http://leica-users.org/mailman/listinfo/lug>for >> >> more information >> > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information > >