Archived posting to the Leica Users Group, 2012/02/04
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Richard, Very nice shot. One reason I've been experimenting with the very wide angle lenses is that they allow me to keep the center of the lens at the horizon (really helps with stitching) but crop the final such that the horizon is not in the center. > Now I want to combine it with focus stacking and Scheimpflug is your uncle. This is where the parallax issue comes in and you are much better off with the rotation point being at the lens nodal point. There is a point at which this becomes rather overwhelming, and you'll wish you'd carried a Canon with it's 24mm Tilt Shift (version 2 only - version 1 was a dog). (Personally, I leave the too-heavy cannon at home and go with a non-stitched, very-wide focus stack to get the near-far sweepers.) I used a Rollei SL66 for years, due in no small part to it's built-in tilt. A huge disappointment with it, however, was the close corner performance of the 50mm Distagon. All retrofocus optics I've used and tested show the same problem of sensitivity to focus. The ZM optics are no exceptions. See the comparison of the 18mm ZM Distagon (retrofocus) and 21mm C-Biogon (relatively symmetrical) at http://www.paulroark.com/BW-Info/Corners-18-v-21mmZM.jpg . This appears to be typical. (I have never tested the Leica 18mm.) I suspect that floating elements are the best and maybe only cure for the focus sensitivity of non-symmetrical designs. Paul www.PaulRoark.com