Changelog entry of sorts

README.md

@@ -4,3 +4,15 @@ Tools to calibrate a microscope
 ## Rotation and handedness
 
 See preprint at https://arxiv.org/abs/2403.08538 for a description and https://github.com/LiberTEM/Microscope-Calibration/blob/main/examples/stem_overfocus.ipynb for an example.
+
+### Changelog
+
+### Since deposition https://doi.org/10.5281/zenodo.10418769
+
+* Fix definition of camera length in the simulator to match figure in
+  https://arxiv.org/pdf/2403.08538.pdf, PR
+  https://github.com/LiberTEM/Microscope-Calibration/pull/17. Preciously, the
+  camera length was defined from the focus point, not the specimen plane. See
+  also https://github.com/TemGym/TemGym/pull/33 for the corresponding update in
+  TemGym. Note that the TemGym model used for calculation was correct, only the
+  alternative manual ray tracing implementation was affected.