One way of celebrating 40 years of such a vulnerable enterprise might be to invite all those who have so generously put their work on show here. Yet nostalgia and extolling the great deeds of the pastmight not be appropriate for the Rencontres, whose history is made up of creative ventures, photographers pushing back the boundaries of the still image and uncertain periods of transition. This history has never been so effervescent. Even so, the temptation to invite back some of the guiding spirits has been too strong, and the programme for 2009 falls into two parts. 40 Years of the Rencontres brings together the artistic directors who helped the idea develop over time and 40 Years of Radical Change shows photographers whose initial Rencontres exhibitions were controversially at variance with the accepted standards of the time.