Correction

[Michael Lloyd]

EOS1DsMK3 manual
70-200mm f2.8L IS handheld@ 200mm

ISO 400
1/250s@ f2.8

This is an example of what surveyors call a section line correction. Basically it has to be done because the earth is a sphere and we humans like our property lines to be straight. Straight lines "drawn" on a sphere converge or diverge depending on direction and which side of the equator that you are on.

I'm going to try this again this morning if the light is good

[Roman Kurywczak]

Hey Michael,
Artists have known this for years......we used a vinishing point......all lines in the scene led to it. I haven't seen the diverging lines. even though the road on the left balances the frame.....going vert and offsetting the road leading to the mountain may only further accentuate the converging lines. Pretty cool concept and looking forward to seeing it in better light.

[Roman Kurywczak]

Hi Peter, I was wrong!!!
I thought Michael was trying to show how the road lines appear to converge on the horizon....even though in fact they are relatively equal distant the entire way.....but I'm not 100% sure that is the case and am myself looking forward to the reply.

PS I just Googled it;definition....... A system for compensating for the inaccuracies in the government survey or the rectangular survey system due to the curvature of the earth in which every fourth township line at 24-mile intervals is used as a correction line.
So my guess is the offset road to the left is the "correction"???

[Julie Kenward]

Whatever the reason or point, I love the image! It's got that "roller coaster" feel to it. I'll have to show this to my survey team in the morning and see if they can tell me what you're talking about!

[Michael Lloyd]

Hi Peter, I was wrong!!!
I thought Michael was trying to show how the road lines appear to converge on the horizon....even though in fact they are relatively equal distant the entire way.....but I'm not 100% sure that is the case and am myself looking forward to the reply.

PS I just Googled it;definition....... A system for compensating for the inaccuracies in the government survey or the rectangular survey system due to the curvature of the earth in which every fourth township line at 24-mile intervals is used as a correction line.
So my guess is the offset road to the left is the "correction"???


Good Googling Roman :D The road, property line, fence, whatever... is moved over. If you've ever come to a tee in the road and had to jog left or right to get back on the road then you've encountered a section line correction. The closer you are to the equator the bigger the "jog". Conversely, the closer you get to the poles the smaller the jog. At least that's how my non-surveyor self sees it.