Ken Waller wrote: >Larry, a few of the reviews for this talked about stacking two, one on top >of the other, at right angles to adjust side to side along with fore & aft. > >How do you adjust for nodal point ?
Technically, it's the entrance pupil of the lens that you're adjusting for. (Every one refers to it as the "nodal point", but that's technically a different point within the lens though you'd need a lens designer to explain the difference). Someone's trying to compile an online database of Entrance Pupil points for various lenses, but as of now there's only one Pentax lens listed (the 10-17 fisheye): http://wiki.panotools.org/Entrance_Pupil_Database The Entrance Pupil is there the lens diaphragm *appears* to be when the lens is viewed from the front. In my experience, just looking into the lens and guestimating the distance works for all but the most critical work. There are various ways of being more precise about it, but in general you line up two objects, one very close to the camera and one very far away, and change the position of the camera forward and back on your pano head until the two objects don't change positions relative to each other when the camera is panned left-right (using live view is best for this). -- 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.
