Flickr API returning duplicate photos

Question

I've come across a confusing issue with the flickr API.

When I do a photo search (flickr.photos.search) and request high page numbers, I often get duplicate photos returned for different page numbers. Here's three URLs, they should each return three sets of different images, however, they - bizarrely - return the same images:

http://api.flickr.com/services/rest/?method=flickr.photos.search&api_key=ca3035f67faa0fcc72b74cf6e396e6a7&tags=gizmo&tag_mode=all&per_page=3&page=6820
http://api.flickr.com/services/rest/?method=flickr.photos.search&api_key=ca3035f67faa0fcc72b74cf6e396e6a7&tags=gizmo&tag_mode=all&per_page=3&page=6821
http://api.flickr.com/services/rest/?method=flickr.photos.search&api_key=ca3035f67faa0fcc72b74cf6e396e6a7&tags=gizmo&tag_mode=all&per_page=3&page=6822

Has anyone else come across this? I seem to be able to recreate this on any tag search.

Cheers.

Answer 1

After further investigation it seems there's an undocumented "feature" build into the API which never allows you to get more than 4000 photos returned from flickr.photos.search.

So whilst 7444 pages is available, it will only let you load the first 1333.