The antonyms for the phrase "bring to a focus" are varied and depend on the context of its usage. If we consider focus as concentration or attention, then the opposite would be to divert or distract attention. To bring out of focus would be an antonym, which means to blur or to make unclear. Lose focus, scattering, and diffuse are other antonyms that could describe a lack of concentration or attention. Similarly, if focus means to bring into a certain order or point, then antonyms would be disorganize, scatter, or make diffused. In essence, antonyms for "bring to a focus" would point to a lack of concentration, organization, and clarity.