Hi David, The irradiance map uses whatever fidelity settings you have when you do the first render and save it. So, if your settings are producing good low res results, it will translate to high res well. Irradiance maps are an ideal time saving tool for multiple renders from the same scene with changes only in camera position - animations included. You probably now this but I have to say it anyhow: if you add something or move objects in your scene besides a camera, the irradiance map becomes invalid for good results.