Archived posting to the Leica Users Group, 1998/02/04
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Henning, In the interest of gaining a better understanding of the complex issues we're discussing, I wish you wouldn't be brief. I have tried to explain my points in detail in the interest of both, teaching something and offering to learn. >> 1) In an ideal (fully corrected) lens, used on flat film, perspective rendition is the same for all lenses, no matter the construction type and focal length. As the field of view increases, the corners of the image relate less and less to our usual visual interpretation, and we call that perspective distortion. << I've been looking for a written proof of this for a very long time, but when Sidney Ray or Stroebel/Zakia write about perspective distortions, their examples are always entirely based on true wide angle and long focus designs; never retrofocus or telephoto versions. Information about the telephoto effect is very scarce and what is available is vague enough to teach little of its severity (or lack of severity). This retrofocus effect I'm arguing is something that I (and many others) have noticed in practice. I've tried to explain many reasons that it can (and to my mind, does) exist. I realise (now at least) that you strongly disagree, but isn't your assertion (of perspective rendition being equal per focal length, whether emulated or not) more a question of interpretation of the texts than it is of a steadfast optical rule? Regards, Danny Gonzalez