I had that same problem with grain on a shoot here in my studio and I couldn’t figure out why. I reset my camera setting to the default on the menu.
BUT… to answer the question, I used two Boris plugins to fix the problem. One is the BCC Magic Sharp and the other was the BCC Noise Reduction.
It absolutely fixed it. In fact is saved the entire shoot which was for PBS.
Roger Bansemer – PaintingAndTravel.com