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I do a lot of GIS work with Alaska data, much of which comes from the State Geo-data Clearinghouse in EPSG: 3338 (NAD83 Alaska Albers), which has a longitude of false origin of -154. Because Alaska is such a large area, making maps away from that longitude results in a skewed appearance where N, S, E, W lines are angled. Here's an example from the northwest part of the state, using the default longitude value (-154) where the black lat/long lines are 68, -163:

enter image description here

In order to make such maps more pleasing to my audience, I often modify the CRS' longitude of false origin to match the longitude of the map center. This can easily be done in either the QGIS Project Properties or ArcMap Data Frame Properties. In the following example, I've changed the longitude of origin from the default -154 to match the map's -163:

enter image description here

I store the data, and do all analysis with the default CRS. Modifying the latitude of origin is only done for final map production and display.

Obviously, the "non-square" effect occurs in other locations and with other CRSs. I use Alaska for illustrative purposes.

AFAIK, there is no drawback to adjusting the longitude of origin for display. To me, what I'm doing is akin to rotating a globe while I look at it, holding my eyes steady. But still, is there something here that is cartographically improper?

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  • There's a difference between a false origin and a central meridian; changing the false origin should not rotate the data. It's not cartographically improper, but it is improper from an IT standpoint to assert an SRID name when your data isn't actually in that spatial reference.
    – Vince
    Feb 28, 2020 at 11:59
  • Good point about the word false. I could swear that I saw the phrase longitude of false origin somewhere in the QGIS project properties. But now I can't find it anywhere. Huh. I now disavow the phrase.
    – Stu Smith
    Mar 1, 2020 at 4:50

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You are free to select the central meridian that you like, but bear in mind that "Alaska Albers" is a projection that is exactly defined, so do not use that name when making maps with CM 163W, instead use "Albers 163W". (Typo edited)

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