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dagewa / DIALS_for_ED_paper

Collaborative manuscript preparation
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R1Q4 wavelength/parallax #16

Closed dagewa closed 6 years ago

dagewa commented 6 years ago

Page 12: What was the electron wavelength used? Parallax correction – what was the effect of the Ewald sphere curvature at the end of the 1k detector (how many z-pixels)? Could that be neglected / missed?

The wavelength is given in Max's paper but it could be made clearer that it is 200 keV here as well.

Definitely worth a short mention of the Kabsch transform

dagewa commented 6 years ago

Reply: Following discussion with co-authors, it is better to remove the sentences about parallax correction from this section. It is brought up because of how the distortion correction could interfere with parallax correction (by which we mean offset of spot centroids due to penetration depth along an oblique ray path), if it were being applied. However, the parallax correction itself is negligible for other reasons: high-energy electrons deposit energy along an unpredictable, meandering track that starts at the point of impact, whereas X-rays penetrate linearly to deeper levels of the detector before releasing their energy all at once, but the precise location along their linear track is unpredictable. That’s why for X-rays is is important to include the obliquity, but far less for electrons.