The latest issue of the Journal for Occultation Astronomy
https://www.iota-es.de/JOA/joa2026_3.pdf
(24 MB, free to download)
carries a detailed article by Mariusz Krukar (PL) on “Impact of the 2026 August 12 Solar Eclipse on Twilight in the Mediterranean Region and other Parts of Europe”, discussing how the twilight sky will be affected by the extended lunar umbra near sunset, including a section on ‘how to observe’ and a request for images and photometric data.
Also, have a look at the comprehensive website
https://eeq.astro-geo-gis.com/tse-2026/
for the discussion applicable to your observing location.
Alex.