So all of you expert render guru's here is a question for you.

Say for example you just completed a long hi res rendering and you notice just one part that has the wrong material.

How can one render an image to a file of just that section around the part at the exact same camera angle, perspective and resolution? Then with PS it could be placed over the previous rendering? This should save significant time.

I have had some success in changing the background to none, isolate a few parts and then save out as a PNG but this does not always work well due to reflections and the location of problematic areas.

I have not tested it out yet but I wonder if a solution could be found in creating a new camera with the same distance and  output resolution and only change the camera view? I will post some of my results.

Any suggestions are welcome.

Thanks,

Jonathan