Archived posting to the Leica Users Group, 2010/04/14
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]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