Good point - both the old and new Corona maps are simply for avoiding applying the LUT and tone mapping in Corona's post to the background image. They do not "un-LUT" the image in any way, but simply avoid applying Corona's changes to it. This should mean, though, that you can apply the same LUT to the render, and leave the background as-is (with the LUT already applied) and all should be well... if I understand what you are doing correctly :) This would make "remove the LUT and then re-apply it in Corona" redundant. But, I could be misunderstanding what you are aiming to do.