On Mon, 17 Jan 2011 14:59 -0500, "Igor Roshchin" <[email protected]> wrote: > > > The rear lens cups for Pentax and Tokina lenses are made so that > can be attached in all three angular orientations (corresponding to > the three tabs). > I have a Tamron lens (70-300) that has a cap that is "polarized", > and can only be attached in one position. Just recently I discovered > that several Sigma lenses come with the same sort of rear caps. > > So, the question is why do they "polarize" the cap? It makes > it so much more inconvenient to put the cap on with one hand... > > Any insights? >
I don't know about the Tamrons but I have a couple of Sigma caps that are designed to fit both the Pentax KPA and Sigma SA mounts. There's a mark on the cap to indicate where you should line up the cap for each mount, so they will only attach in the one location (unless you modify the cap by cutting off some of the plastic tabs). Maybe the Tamron caps are also designed for two different mounts. Cheers Brian ++++++++++++++++++++++++++++++++++ Brian Walters Western Sydney Australia http://lyons-ryan.org/southernlight/ -- -- http://www.fastmail.fm - A no graphics, no pop-ups email service -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
