Vanishing points & wide angle lens.
I've been practicing the fundamentals tonight. After working on linear perspective, I came across a photograph on Wikipedia that I wanted to use as a study.
I began extending parallel lines to vanishing points and estimated a horizon line. Keeping in mind that all parallel lines have the same vanishing point, I was surprised to see that different structures, though likely to have the same orientation, had clearly different vanishing points. I'm not a photography guy, though I wondered if the appearance of a very wide angle field of view had something to do with this. Also, the photo appears to be cropped together from two separate photographs, or perhaps pages of a book.
I've looked through photography websites and I've only learned that vertical lines converge sharply, when viewed down field, in a wide angle shot. I've also attempted the same process with other wide angle photos and found similar, though not as extreme, results.
So what's the take away lesson from all this? This doesn't reconcile well with what I've been practicing and understand about linear perspective. Did I make a fundamental mistake in drawing these parallel lines or setting up vanishing points? Or am I to understand there is something different in this view, something creating an exception to the rules?
Two point perspective & wide field of view?
I've been working on the fundamentals; drawing cubes and spheres with attention to values, figure studies and drawings that emphasize perspective. Coming across an intersting photograph on Wikipedia, which you can find here, I felt compelled to extend parallel lines to vanishing points and approximate a horizon. Attached is that product.
Well, I've somewhat confused myself. Everything I have read about linear perspective is that all parallel lines share a common vanishing point. In this photograph, individual structures that I would expect to be oriented in the same direction sometimes vanish to very different points. I can see that the picture is distorted, possibly cropped together, potentially scanned from a book and maybe taken with some kind of wide angle lens. Can those circumstances achieve the noted effect? What I'm seeing here doesn't reconcile with what I have been learning, and I'm just trying to develop my understanding to explain why.
I did some reading on photography websites about wide angle lenses, though didn't find much relevant to the matter at hand. I did play around with some other photos that were said to be taken with a wide angle lens. Ultimately, I wasn't able to find such extreme outcomes. So have I made a fundamental error, or does this photograph bend the rules of linear perspective?
Thank you for any wisdom, experience or advice!
** Edit 2-10-12 8:50 pm EST - I understand the statement that "all parallel lines share a common vanishing point" is not accurate. I wanted to mention this and spare the time of a well-intentioned reader from posting a detailed explanation that lines drawn in linear perspective that appear parallel to the viewing plane of the observer will not converge towards vanishing points.