----- Original Message ----- From: "John Francis" Subject: Re: Pentax K28mm 3.5 shift
>> >> With a perspective shift lens you're using a larger-image-circle lens >> and those generally (though not always) have lower resolution than >> standard 35mm lenses. And by using the shift capability you are, by >> definition, using more of the edge of the image circle, which is >> virtually always lower resolution than the center. > > While that's true for a normal lens, it isn't necessarily so for a > shift lens - it gets the increased image circle by means of the shift. Ummmm, no. Without the larger image circle available, the shifting can not happen. The 28/3.5 allows for 11mm of shift. Presuming this is 11mm off each axis, it has to have 74mm of good image circle to to this, 63mm if the lens only shifts horizontally (I don't know if it has vertical shift). Contrast this to a lens that only needs to cover the 35mm frame at 43mm of good image circle. William Robb -- 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.
