Archived posting to the Leica Users Group, 2005/05/17

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Subject: [Leica] PAW 20 Millenium Bridge and St. Paul's - Try this!!
From: lkhermann at bresnan.net (lkhermann)
Date: Tue May 17 17:32:56 2005
References: <428A64F5.2080904@summaventures.com> <4289F4EB.3090809@summaventures.com> <4289F66A.1080407@gmx.de> <428A64F5.2080904@summaventures.com>

Douglas,
         Sounds like a better case than mine.  With my astigmatism all 
picture frames are slightly larger on one side and one of two glasses of 
wine with equal volumes always appears slightly larger.  I claim that this 
astigmatism accounts for my sloping horizons, the verticals are usually 
OK.  Perhaps it will be better when I get "bionic" lens for my flaring mark 
I models.
Lee


At 12:46 AM 5/18/2005 +0200, you wrote:
>Much better Peter,
>I know I'm a nit-picker, shifts, be they ever so small, just hit me
>right in the optic nerve.
>
>It's a matter of "Seismogram Eyeball", I spent over 30 years having to 
>recognise amplitude and phase differences of seismic signals and logs, or 
>time shifts of around 1 millisecond on seismic profiles (at a standard 
>display scale that's about 0.1mm differences or smaller).Not finding the 
>signal could mean the difference between drilling on a dry prospect or 
>finding a gas reservoir.
>"Sharps Eyes" had quite a reputation in the world of exploration geophysics.
>
>It has a nasty side effect - I turned into a habitual picture frame 
>straightener,BTW my wife is an architect and has the same gift/problem.
>
>I put a narrow grid over the picture to check how much I was out on my 
>first estimate, and I came to 0.4 - 0.85 degrees left correction. 0.85 at 
>the left hand edge (the parapet and windows of the rectangular building), 
>0.5 over the ends of the handrails at each side of the shot, based on 
>putting the spire of St Pauls as a vertical axis dead centre. 0.4 - 0.5 
>also fits the columns of the dome. 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.
>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
>>
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>>Leica Users Group.
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In reply to: Message from pdzwig at summaventures.com (Peter Dzwig) ([Leica] PAW 20 Millenium Bridge and St. Paul's - Try this!!)
Message from pdzwig at summaventures.com (Peter Dzwig) ([Leica] PAW 20 Millenium Bridge and St. Paul's)
Message from douglas.sharp at gmx.de (Douglas Sharp) ([Leica] PAW 20 Millenium Bridge and St. Paul's)
Message from douglas.sharp at gmx.de (Douglas Sharp) ([Leica] PAW 20 Millenium Bridge and St. Paul's - Try this!!)