|André Kertész: Boat at Sunset on the Danube. Esztergom, 1917 (1967)|
What can we actually see in this photograph? At the very first superficial glance this is like a solar halo with its reflection in the river. The light also becomes diffuse around it, so had the photo been modified, this would really be a masterpiece of manipulation from 1917. But Kertész was known for his documentary style not for remaking his photos.
However, if it was a halo, the image must have been taken by a lens with ultra wide focal length, which would not be commensurate with the boat in the foreground. The size of the feature could indicate a corona, but would a corona appear like this in a photograph made with a gelatin silver photographic process and the camera Kertész was using at this time: a Voigtländer Alpin 9×12 cm with a 6.3 lens?
All ideas are welcome.
Nicolas Lefaudeux has given an explanation for the riddle in the comments section. The image (see below) he found of the same Kertész photo with but a different development confirms his point.
The photo appeared in maimanohaz.blog.hu in 2015.