I recently was privileged to visit Chartres Cathedral with my group of Paris photographers. The upper two images were made inside Our Lady of Chartres with a fisheye lens and the camera on a tripod. You can see that the inside has been cleaned and looks almost new. On my previous visit, in 2013, some parts had been cleaned but the ceiling was untouched, and scaffolding was still up for cleaning and restoring the rest (as shown in the bottom image).
Click here for the blog story from my 2013 visit to Chartres.