In my opinion, it kind of depends on what the pictures show, and on what descriptions are given. I don't want 50 similar pictures of the tower of Pisa. I do want 50 pictures if this one is taking at sunset, that one shows the surroundings as well and the third one is from an unusual direction.
I agree with you each picture should bring some information, it unuseful to have 30 time the same picture. I think that it's very useful to have many picture (and detailed one) of the same object. Picture ofen bring more information than a long text. Currently I have also a problem on how to incorporate those images in an article. Currently I m creating a gallery where I m putting all the images with a short comment on each picture. see for instance: http://fr.wikipedia.org/wiki/Cath%C3%A9drale_de_Lausanne/galerie http://fr.wikipedia.org/wiki/Notre-Dame_de_Paris/galerie
Greatpatton