Archived posting to the Leica Users Group, 2012/06/11

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Subject: [Leica] Using M (and R) glass on a Sony NEX-7 Now DATA
From: mark at rabinergroup.com (Mark Rabiner)
Date: Mon, 11 Jun 2012 03:45:09 -0400

Its no surprise to me that the 60 is performing better than the 50.

- - from my iRabs.
Mark Rabiner
http://gallery.leica-users.org/v/lugalrabs/springdays/


> From: Jim Nichols <jhnichols at lighttube.net>
> Reply-To: Leica Users Group <lug at leica-users.org>
> Date: Sun, 10 Jun 2012 14:45:47 -0500
> To: Leica Users Group <lug at leica-users.org>
> Subject: Re: [Leica] Using M (and R) glass on a Sony NEX-7 Now DATA
> 
> 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 for more information
>> 
>> 
> 
> 
> 
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information




In reply to: Message from jhnichols at lighttube.net (Jim Nichols) ([Leica] Using M (and R) glass on a Sony NEX-7 Now DATA)