Archived posting to the Leica Users Group, 2005/05/18
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Philippe, "Verticals" can be deceiving. This was taken from the other end of the bridge: http://gallery.leica-users.org/album28/StPaulsSteps200505 the building nearest you on the St. Paul's side of the road actually has verticals that DO slant back by 2 - 3 degrees (check against the pillars, the buildings opposite on the left, buildings behind etc). The path is cambered. It would appear that the steps aren't exactly centred on the window (not main entrance. See also: http://www.streetmap.co.uk/streetmap.dll?G2M?X=532057&Y=180754&A=Y&Z=1 where it is very apparent that St. Pauls doesn't run sue East-West (altar at East end, but slightly North of East and the river and buildings run ESE. The plate glass in the original photo means that there are all sorts of deceptive lines and planes and half-mirrored images floating about which also give (and gave the photographer) optical illusions. I was interested in trying to maintain reflections and also to get St. Paul's in place. But in any case, did you like the shot? which after all is what it is all about. Peter Philippe Orlent wrote: > The strange thing with the shot is that if you level the horizon (1.72? > CCW) > it still doesn't look horizontal. If you put the verticals at 90? (as is > the > original), it isn't either. If you level the pavement in front of the > bridge > (0.85? CCW), it starts to look horizontal. But the verticals aren't 100% > vertical any more. > > So it might have something to do with cam tilt. > Then again, if it were cam tilt, the verticals wouldn't be parallel. Which > they are. > > So it might have something to do with your VF frame that isn't 100% > parallel > with your cam body. Which would be strange because it would have shown up > in > other shots, too. > > So it migh have something to do with the fact that (if so) it is a RF: the > main entrance of St. Paul's is slightly of centre, as often happens when > you > try to frame objects behind each other in one axis in the centre of the VF: > the final result is seldomly dead on and plays strange optical tricks with > the eye. But that wouldn't explain everything. > > I'm pretty sure that you saw it dead centre through your VF and that it > looked symmetrical when you shot it. > > So my guess is that the bridge is a bit to the left of the axis of St. > Paul's. Thus, you being in the centre of the bridge and following the > bridge's axis, the horizon tilted a bit CW, keeping the verticals parallel. > This rises an interesting question: did Foster make (apart from the > oscillation issue) an architectural mistake? The bridge sure doesn't seem > out of the axis of St-Paul's at first sight, but it might be. I can't > remember what the situation was when I visited Tate Modern, but I would > have > seen it, though. I suppose he chose to be perpendicular to the Thames, and > St. Paul's is just not parallel to the river. In other words, Sir > Christopher Wren made the "mistake"? > > I seems to be the latter: > > http://www.ph.ucla.edu/epi/snow/1859map/map1859_j-l_19-21.html > Or > http://tinyurl.com/a2fcy > > In any case: I don't think it is possible to get it perfect when shooting > or > by just tilting the horizon: some more Photoshop fiddling might be needed, > if you feel like it :-) > > Hey, this is fun! > > > >>From: Peter Dzwig <pdzwig@summaventures.com> >>Organization: Summa Ventures Ltd >>Reply-To: Leica Users Group <lug@leica-users.org> >>Date: Wed, 18 May 2005 09:18:11 +0100 >>To: Leica Users Group <lug@leica-users.org> >>Subject: Re: [Leica] PAW 20 Millenium Bridge and St. Paul's - Try this!! >> >>Douglas Sharp wrote: >> >> This could infer a tiny bit >> >>>of lens distortion, that the camera was not quite in the horizontal >>>plane, possibly tilted up a bit, or that the scanned negative was not >>>quite flat. >> >>Think I was sober..no seriously since I have a slight astigmatism it's not >>inconceivable that I didn't notoce that I was slightly off level. >> >>Thanks for your help. >> >>Keep looking, >> >>Peter >> >>>cheers >>>Douglas >>> >>>Peter Dzwig wrote: >>> >>> >>>>Douglas Sharp wrote: >>>> >>>> >>>>>An excellent shot Peter, >>>>>love the symmetry! >>>>>but couldn't it take a slight correction of the horizontal? >>>>>I think its about 1 or 1.5 degrees out of kilter. Otherwise perfect >>>>>for me. >>>>>cheers >>>>>Douglas >>>>> >>>> >>>>Douglas and List, >>>> >>>>see which one you you think is straight... >>>> >>>>http://gallery.leica-users.org/album164/MilleniumBridge200505 >>>> >>>>the original >>>> >>>>or: >>>> >>>>http://gallery.leica-users.org/album164/MilleniumBridge200505Rot1 >>>> >>>>I think that it is it straightened...it took 0.4 degrees of rotation. >>>>If that does truly fix it (I am not entirely sure) Douglas you have >>>>very sharp eyes!! >>>> >>>>All the best, >>>> >>>>Peter >>>> >>>> >>>>_______________________________________________ >>>>Leica Users Group. >>>>See http://leica-users.org/mailman/listinfo/lug for more information >>>> >>>> >>> >>>_______________________________________________ >>>Leica Users Group. >>>See http://leica-users.org/mailman/listinfo/lug for more information >>> >>> >> >> >> >>_______________________________________________ >>Leica Users Group. >>See http://leica-users.org/mailman/listinfo/lug for more information >> > > > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information > >