sorry vince i m abit confuse.
going by the way the discussion is developing, i think it's a matter of courtesy... the agency can use ur photo w/o crediting u, since the photo in the eyes of the law no longer belongs to u. It's a matter of whether they are nice enuff to tell u or not.. they dun have to, but it's good if they do
as quoted by jkaiser, since the photographer sold or work for the magazine agency or model agency issit that the copyright owner is the magazine agency? and if the agency let say let me use the photo, do I still need to seek permission from the photographer?
In this thread, the TS was paid for the shoot with the model and in the absent of a contract stating the condition of sale, it's considered an unconditional sale. This being the case, the model have every right to use the image as she sees fit. The model agency don't need to credit or ask you for permission as the model paid for the copyrights to the image.
In your example, you mentioned that the photographer sold the image to the magazine and you use a page of the magazine. Though you have been given permission by the magazine, you're not sure of the condition of sale between the photographer and the magazine hence Vince suggested you check with both.
If the photographer works for the magazine, than depanding on his term of employment, the copyrights belongs to the magazine.