Hi All, John Carmichael wrote:
> But I discovered that by using digital editing, you can stretch or > compress a photo so that it appears that camara was directly over the > dial! I discovered this while using the "perspective" and "distort" > features of Adobe Photo Delux. I sometimes apply the same trick, using Paint Shop Pro. Starting with a picture of a rectangular dial face taken at an arbitrary angle, this involves 4 steps: the horizontal and vertical perspective tools are used to make the sides parallel, then the horizontal and vertical skewing tools are used to make them parallel to the picture frame. My question, however, is: does this procedure guarantee to yield the correct result? That is: is the resulting height/width ratio equal to that of the original? If not, angles between hour lines would be distorted. As a consequence, it would be impossible to check the correctness of the hour line layout, or to calculate the latitude for which the dial was designed. Kind regards, Frans ===================================== Frans W. Maes Peize, The Netherlands 53.1 N, 6.5 E www.biol.rug.nl/maes/sundials/ =====================================
