Archived posting to the Leica Users Group, 2005/03/19
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 5:18 PM -0800 3/19/05, Frank Filippone wrote: >Thanks Henning, that helped a lot..... > >So for a specific lens FL is there a point of Iris size and nodal placement >where this is no longer an issue? ie, are ALL F2 50mm Lneses equally bad? >( Put in your own brand, FL and Max F stop here... it does not >matter...).... Are the specs on a given FL about the same, regardless of >brand name? > >This is now getting really interesting.......there is a lot to learn.....and >a lot more to understand..... > > >Frank Filippone >red735i@earthlink.net The variables are too many, Frank. Some lenses with the same max. aperture that look the same and act the same on film might have widely different rear nodal points, and also the size of the rear nodal plane is not the same for a given aperture and FL. Then come the sensor variables.... You just have to try and see. A couple of months ago I posted various vignetting patterns with wideangle lenses on the R-D1, all taken at f/8. You can see the different amounts of vignetting on different lenses, like the 12mm Cosina was better than the 15, and the 21ASPH was a lot better than the 21VC (all at f/8, remember). This shows that the differences might be more due to lens design than the apertures per se. http://www.archiphoto.com/Various/RD1vignette/index.htm -- * Henning J. Wulff /|\ Wulff Photography & Design /###\ mailto:henningw@archiphoto.com |[ ]| http://www.archiphoto.com