Thx belly, I'll give it a try right now. I do have the denoiser on, i'll swithc it offPROH, it can be my last resort ;)
Can something like that be implemented into Corona?https://docs.chaosgroup.com/display/VRAY3MAX/Rendering+Very+Large+Images
Was not able to render in one shot, did 8 fragments(using crop in 3ds max), attached in PS later.