thanks. awesome set of links On Oct 23, 2012, at 9:24 PM, David Parsons wrote:
> There are more than 4 basic lens designs, and they are mixed and > matched depending on the lens design. If you really want to know > about lens design, read these articles: > > http://www.lensrentals.com/blog/2011/08/lens-geneology-part-1 > http://www.lensrentals.com/blog/2011/09/lens-genealogy-part-2 > > http://www.lensrentals.com/blog/2011/01/cooking-with-glass > https://www.lensrentals.com/blog/2010/11/the-schott-heard-around-the-world > http://www.lensrentals.com/blog/2011/02/who-invented-the-telephoto-lens > https://www.lensrentals.com/blog/2010/10/from-petzvals-sum-to-abbes-number > > On Tue, Oct 23, 2012 at 10:06 PM, Larry Colen <l...@red4est.com> wrote: >> >> On Oct 23, 2012, at 2:15 PM, Brian Walters wrote: >> >>> Interesting article that uses a K-5 and a Sigma 50-500 mm HSM lens. The >>> article doesn't say what focal length was used in the tests but presumably >>> it was the long end. >>> >>> http://www.digitalversus.com/digital-camera/image-stabilisers-optical-mechanical-a1608.html >> >> Interesting. I assume that they tried it at 500mm, how about at 50mm? >> >> I remember seeing something recently about how there are only about four >> different basic types of lenses, and that the lens formula that works for >> zoom lenses is only good to about f/2.8. I suspect that it takes one of >> those lens formula in order to do optical stabilization. >> >> I also remember reading about how having a moving element in the optical >> path decreases the sharpness of the photo. I note that he doesn't perform >> MTF calculations on the images, so he's not actually quantifying levels of >> sharpness with the different methods. >> >>> >> >> -- >> Larry Colen l...@red4est.com sent from i4est >> >> >> >> >> >> -- >> PDML Pentax-Discuss Mail List >> PDML@pdml.net >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and >> follow the directions. > > > > -- > David Parsons Photography > http://www.davidparsonsphoto.com > > Aloha Photographer Photoblog > http://alohaphotog.blogspot.com/ > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- Larry Colen l...@red4est.com sent from i4est -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
