Hmmm. Looks like I need a bit more education on this subject. (Thanks John!)
What most people will agree on is that the (optics-less) extension tube will do less image degradation than anything with another optical element (although the Tamrons are considered high quality in that area). The benefit of the teleconverters is that they will "enbiggen" (increase) your distance from lens to subject, which is often helpful if trying to capture something skitterish or shy. On things that can't fly away (most plants and fungi), the extension tube will generally be a better option. On Fri, Jul 13, 2012 at 2:42 PM, John Francis <[email protected]> wrote: > On Fri, Jul 13, 2012 at 01:48:33PM -0500, Darren Addy wrote: >> That page misses one option (one that I only became aware of recently). >> Tamron also made an Adaptall2 *Extension Tube* specifically for the SP >> 90/2.5 that will get it to 1:1. >> The obvious benefit to the tube is that you don't lose the two stops >> of light that you would with the 01F teleconverter. > > The laws of physics suggest you are mistaken here; if you spread the > light energy out over a larger area it's not going to be as bright, > no matter how that spreading is done. You'll lose a little bit of > the light with an optical TC - nothing is 100% transparent - but to > a first approximation the two ways of getting to 1:1 are equivalent. > > > -- > 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. -- 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.
