Archived posting to the Leica Users Group, 2010/04/14

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Subject: [Leica] M Lenses on GF-1
From: jsmith342 at gmail.com (Jeffery Smith)
Date: Wed, 14 Apr 2010 16:48:30 -0500
References: <DC4B73A4105FCE4FAE0CEF799BF84B36052E9B30@case-email.casefoods.com> <EA8C6053-8396-414D-BC4F-4C30C353BF04@gmail.com> <p0623091bc7ebe1223e25@[192.168.1.5]>

I don't really recall Olympus's exact wording. I think the only way to get 
perpendicular light rays to hit would be to have a very large diameter rear 
element, and still they would not be actually perpendicular, but maybe more 
perpendicular. 



On Apr 14, 2010, at 4:22 PM, Henning Wulff wrote:

> The vignetting of the 45-200 is due to the attempt by Panasonic to keep 
> the lens as small as possible, so vignetting appears at wider apertures 
> due to cutoff of off-axis rays. If the vignetting were due to light rays 
> hitting the sensor at a too steep angle, the aperture wouldn't make a 
> difference. Also the latter is an issue with shorter lenses where the rear 
> exit pupil is too close to the sensor. Not an issue with the 45-200.
> 
> As I mentioned before, the vignetting doesn't bother me since the lens is 
> only for digital use, and the software that I use certainly has no 
> problems fixing the vignetting if so desire.
> 
> BTW, that Olympus claim is not true; I'm not sure they actually said that. 
> Their lenses are 'more telecentric' than those of most other 
> manufacturers; true telecentricity causes so many problems that it's 
> really not worth it except for certain industrial uses.
> 
> 
> 
>> Is the vignetting due to the light rays hitting it at less than a 
>> perpendicular angle? One of Olympus's big selling points on their lenses 
>> is that the light path is exactly parallel to the APS-sized sensor behind 
>> the lens.
>> 
>> Jeffery
>> 
>> 
>> On Apr 14, 2010, at 3:05 PM, David Rodgers wrote:
>> 
>>> I don't doubt what you're saying. I'm just a bit mystified how a lens
>>> can vignette on a sensor that's half the size of film that it was
>>> designed to cover. That hasn't been my experience with M lenses on Micro
>>> Four Thirds. I actually have to use Lightroom to add a little forced
>>> vignetting because in many cases I like that look.
>>> 
>>> I'm also perplexed at how Contax G lenses can be materially better on
>>> Micro Four Thirds than are Leica M lenses, or even CV lenses for that
>>> matter. While I haven't used all on Micro Four Thirds I have used them
>>> all on film and for the most part they're all pretty good. Thus I'm
>>> curious as to why the performance would be so different on Micro Four
>>> Thirds. What kind of adapters are you using?
>>> 
>>> The main issues I see in using Lumix lenses versus Leica M lenses on the
>>> GF-1 is that Lumix lenses have AF and Leica M lenses don't. It's easy to
>>> miss focus, particularly with the longer lenses wide open. A focus
>>> assist LED in the viewfinder would be a nice feature to have.
>>> 
>>> Dave R
>>> 
>>> 
>>> -----Original Message-----
>>> From: lug-bounces+drodgers=casefarms.com at leica-users.org
>>> [mailto:lug-bounces+drodgers=casefarms.com at leica-users.org] On Behalf 
>>> Of
>>> Simon Ogilvie
>>> Sent: Wednesday, April 14, 2010 3:03 PM
>>> To: lug at leica-users.org
>>> Subject: Re: [Leica] M Lenses on GF-1
>>> 
>>> I've used a variety of Leica and Voigtlander M lenses on a G1, and
>>> also a couple of Contax G lenses (45/2 and 90/2.8).  Without exception
>>> I found the M lenses disappointing with either smearing, vignetting or
>>> other faults.  The Contax G lenses however are superb on the micro 4/3
>>> format and I much prefer the 90 to the 90 Summicron and the 45 to my
>>> (now sold) 50 Summilux.
>>> 
>>> I've also been a bit disappointed with the performance of the
>>> Panasonic 45-200.  I haven't checked but it's possible most of the
>>> shots I've taken have been at or close to full aperture, so the
>>> vignetting at the long end is very noticeable.  It also doesn't appear
>>> very sharp at the long end either.  Maybe the upcoming 100-300 will be
>>> better - I hope so.
>>> 
>>> _______________________________________________
>>> 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
> 
> -- 
> 
>   *            Henning J. Wulff
>  /|\      Wulff Photography & Design
> /###\   mailto:henningw at archiphoto.com
> |[ ]|     http://www.archiphoto.com
> 
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information



Replies: Reply from imagist3 at mac.com (George Lottermoser) ([Leica] M Lenses on GF-1)
In reply to: Message from drodgers at casefarms.com (David Rodgers) ([Leica] M Lenses on GF-1)
Message from jsmith342 at gmail.com (Jeffery Smith) ([Leica] M Lenses on GF-1)
Message from henningw at archiphoto.com (Henning Wulff) ([Leica] M Lenses on GF-1)