CollinB wrote: >>The DA* 16-50 can be superb, but many of them have element alignment >problems. You have to test and insist on a good copy or correct repair. >>Paul > >What does one look for in the image? Coma? Corner softness?
Just take a photo of a flat surface (the classic brick wall test, for example) perpendicular to the camera/lens. Focus in the center with the lens wide open. Look at the resulting image and check that the left and right edges are *equally* sharp; do the same for the top vs. bottom. I thought that the decentered lenses were just in the early production runs of this lens (though I could be mistaken). I have a good one and it's a totally superb lens. -- Mark Roberts - Photography & Multimedia www.robertstech.com -- 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.
