Firstly, we need to unpack what is is meant by poetics. It is broader than poetry in that it implies a creative act that points to something beyond itself. This refers to poiesis or a bringing into being: an unending creative struggle to express that which conditions and informs our worlds of meaning and yet resists being exhaustively articulated in the terms of these worlds.
How does this conception of poetics relate to visual art including photography?
The starting point would have to be Kant, since it was he who first systematically outlined the logical grammar or conceptual machinery of aesthetics though his categorical separation of knowledge /truth as in the natural sciences, morality and aesthetic in modernity into separate domains. In the Critique of Judgement Kant acknowledges that scientific cognition excludes aspects of ourselves from its view of nature and that this must be accounted in other than cognitive terms.
He does this in terms of an aesthetics that is based on the imagination, autonomous art, intuition, aesthetic ideas, taste and the lack of concept. Kant, in other words, in inscribing art with the autonomous domain of the aesthetic relegates art and aesthetics to what is outside truth and goodness. Autonomous art is autonomous from truth and morality.