Issue with EMEBSDDI in EMsoft 5.0: incorrect quantitative orientations about emsoft HOT 4 CLOSED

Hi @christiankwalters,

based on the orientation maps, your results from EMsoft seem consistent, while there is a slight (systematic?) change in the orientation. Might this be related to your projection center? How did you arrive at y_pc = 13.055? I get y_pc = (Nx * y*) - (Ny / 2) = (311 * 0.551) - (256 / 2) = 43.361. I based this expression on the assumptions listed in kikuchipy's docs. Such a change in PC should cause a change in orientation.

from emsoft.

Thanks, @hakonanes, for your quick reply!

Your suggested value of y_pc was exactly right, and my issue seems to be resolved now. Indexing the same portion of the scan shows good agreement between the EMsoft results and those of AZtec/kikuchipy.

I think I understand the source of my confusion now. In the Pattern Simulation wiki page for EMsoft, the pattern center relations agree with your calculation for y_pc:

pcx = Nx x* - Nx/2
pcy = Nx y* - Ny/2
L = W z*.

In my case, I was performing these calculations based on M. Jackson's 2019 paper, which has the relation as y_pc = (Ny * y*) - (Ny/2) = 256*(0.551 - 0.5) = 13.056.

Maybe the correct procedure has changed since 2019. In any event, I'm glad this orientation issue seems to be fixed. Thanks very much for your help!

Best,
Christian

from emsoft.

Great! I'm glad this solved your issue.

The beta version of EMsoft v6.0 (EMsoftOO) has a new PC conversion program EMEBSDpc (https://github.com/EMsoft-org/EMsoftOO/blob/develop/NamelistTemplates/EMEBSDpc.template). This and the wiki should have the most updated conversions.

An alternative is to use kikuchipy, which I did to check your PC (current version is v0.8.4):

>>> import kikuchipy as kp
>>> det = kp.detectors.EBSDDetector(
...     (256, 311), pc=[0.52, 0.551, 0.659], convention="oxford", px_size=75.88
... )
>>> det.pc_emsoft()
array([[-6.22000000e+00,  4.33610000e+01,  1.55515301e+04]])

from emsoft.

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