Talk:Einstein radius

I am not familiar with SVG editing but someone who is could modify and complete the "Gravitational_lens_geometry.svg" image to make it clearer by:

- changing the "D"'s in D_LS, D_L and D_S to lowercase & italic "d"'s so that it matches the notations in the articles that uses the image (presently: Einstein radius, Einstein ring);

- renaming α and b to α₁ and b₁;

- adding θ₂, b₂ and α₂ on the lower half of the figure (we could then complete the study of the article with this lower ray...).

Besides, I personally find it a bit misleading that the first part of the upper ray (from the source to the lens plane) happens to be almost perpendicular to the lens plane: I would exagerate α₁ a little so that it doesn't look this way.

Thanks in advance to the person who will take these changes in charge! — Preceding unsigned comment added by 88.141.245.144 (talk) 10:41, 1 February 2013 (UTC)

I agree we should rename α and b to α₁ and b₁. I'll try to edit the svg in inkscape when I have time. In the references I've seen, they use capital D for angular diameter distance, but if this is not standard, I agree we should change it too. How will labelling the lower ray help complete the study of the article?

We also have to remember to update the other language wikipedia articles to match the diagram. Most languages use the same notation as the English article, but the Japanese uses capital D, and the Korean and Galician (Gallego) articles use the notation of the diagram. Note that the Galician article uses a png which is listed separately on Wikimedia commons.

Gneisss (talk) 18:42, 7 August 2019 (UTC)