What's the best way to cite the source of a photo?

Question

My recent answer included a photo for illustration. I had done like I always (try do) do and added a citation under the photo.

However, an edit was made that moved the citation into the photo's alt-text. This made the citation invisible to a casual viewer, although if you were scraping the page it would be in the output.

What's the preferred way to cite the source of a photo?

Answer 1

The alt text, or formally alt attribute, is meant for a short description of the image, to be used when the image cannot be displayed, typically used by screen readers for visually impaired users.

A source citation is not an adequate description of the image and as such should not be put in the alt text, but rather as a separate line underneath the image.