For those photographers who do not want to use digital tools, it's maybe useful to remind the existence of special objectives used mainly for architectural (exterior and interior) pictures, with the ability to correct the perspective by sliding the lens in any direction.
One such objective is the PC Nikkor (28mm f/3.5) by Nikon, where PC stands for Perspective Correction. The focal length is short, and probably better adapted to buildings than to details, unless the position of the sundial allows for getting relatively close, but it can be useful for horizontal dials. Another by Nikon is the PC Micro Nikkor (85mm f/2.8), which is maybe better adapted to the sundials task. A comparison of digital vs optical correction could be interesting too? Thierry vs [EMAIL PROTECTED] wrote: > Willy, Frans, et.al., > > Willy suggested: > > > ... Photograph a drawing of a vertical sundial > >and compare the drawing with the corrected photo. > .... . > > Might I suggest a test photo of a Cartesian grid > (or a checkers-, or chess-, board? The analysis > would then be simpler and more generalized. > > Also, this subject is covered in textbooks on use > of aerial photography for mapmaking. In English, > the topic is called 'photo-rectification'. > > Sciagraphically, > Bill Maddux > > Frans, > >
