I haven't tried the 20-40, much as I'd like to, but I think your choice comes down to whether you can put up with the additional size and weight of the 16-50 it's wider at the wide end and longer at the long end and faster beyond 20mm. As a working tool that makes it the clear choice for someone who has to choose between these two lenses... *unless* the size/weight factor is important. I suppose the 20-40 could possibly be better optically than the 16-50 but I can't imagine there's enough of a difference to get worked up about: The 16-50 is one of the best lenses I've ever used.
Downsides of the 16-50 are the more "plasticky" feel of the construction (though mine's been kicked around extensively for years without a hiccup, so I don't see any durability issue) and the larger 77mm filter size. -- Mark Roberts - Photography & Multimedia www.robertstech.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.
