Just went to the State Gallery Homepage and saw that they had a photo exhibition earlier this year (Tracy Moffat), as well as last year (Candid Camera Australian Docu. Photography 1950's to 70's) so they do show photographs but don't put them on permanent display which is the right decision from a conservatory point of view. I work part time in a museum (with a photo collection my work place) and we rarely show photographs for longer than 2 months with a maximum illumination of 50lx. The Exhibition of the department I work in constantly changes one time watercolours, then waxmodels, then photographs, etc... but never longer than 2 to maximum 3 months.