this seems to be a subject that we all had a go at (except Brian?). Re-post of an edition being more careful with DxO; now more within my usual range . I don't even seem to have attempted to use the WA end of the lens, being more interested in the unusual purlin support off the arches and only enough of the arches to establish a rhythm.
see also Mark's http://www.pbase.com/46rossi/image/142763867
Martin's: http://www.pbase.com/mjlamoon/image/142789008
John's: http://www.pbase.com/jhaydnreynolds/image/142706242