Pentax K28mm 3.5 shift

John Francis johnf at
Mon May 19 02:17:20 EDT 2008

On Sun, May 18, 2008 at 07:03:29PM -0400, Mark Roberts wrote:
> John Francis wrote:
> > On Sat, May 17, 2008 at 08:23:22PM -0700, Bob Blakely wrote:
> >> To do perspective correction in photoshop or any other imaging software, you 
> >> must loose pixels, synthisize pixels or both. Shift is still the way for 
> >> digital purists.
> > 
> > That's possibly true (but watch out for those loose pixels :-)
> > But unless you're printing on a device with native resolution that
> > exactly matches your original image, you're going to end up with
> > lost and/or synthesized pixels, anyway.
> 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.

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