Archived posting to the Leica Users Group, 2012/03/05
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Thank you Joh and Tim, it makes sense now. Tim, your reference to the square format particularly helps. Thanks So the Biogon SWC is good - great in fact, but it's still limited by physics :-) On Mon, Mar 5, 2012 at 10:26 AM, Tim Gray <tgray at 125px.com> wrote: > On Mar 04, 2012 at 04:04 AM -0800, Richard Man wrote: > >> Yes, but my question is, how come the SWC Biogon doesn't seem to have the >> distortion of circles becoming oblong on the edges, or am I incorrect in >> saying that? >> > > You are incorrect in saying that. What you are referring to is often > called perspective distortion, and any lens that has a rectangular > projection has it. > > What the SWC doesn't have is barrel, pincushion, wave, mustache, or other > types of distortion that makes straight lines not straight. > > Personally I think the SWC downplays perspective distortion a bit > (relative to 35mm lenses) because of its square format. The diagonal field > of view (FOV) is 91 degrees, similar to the diagonal FOV of 21mm on a 35mm > camera. But the horizontal/vertical FOV is only 72 degrees, which is > slightly less than the horizontal FOV of a 24mm lens for 35mm format. > Lastly, it's vertical FOV is similar to a 15-16mm lens's vertical FOV on > 35mm. So in some senses (diagonally), it's as wide as a 21mm lens, in > other senses (horizontally), it's narrower, and vertically, it's a good > deal wider. Compared to a 35mm lens, it's much more balanced in the FOV it > provides in different directions on the basis of it being a square format. > > When I had an SWC, I wasn't putting peoples heads in the corners of the > frame; if they were near the edge, they were much more likely near the top > or the side, so you get a bit less perspective distortion there. > > > ______________________________**_________________ > Leica Users Group. > See > http://leica-users.org/**mailman/listinfo/lug<http://leica-users.org/mailman/listinfo/lug>for > more information > -- // richard <http://www.richardmanphoto.com>