I have PSE 12. Although a total amateur I have had good results manipulating CR2 files from my Canon 60D. I recently bought a Lumix ZS40 for a walk-around camera. The RAW files are RW2 format. I can get good results for color and lighting but if I make ANY changes the images become very grainy. Any idea why this would be? Camera? File format? PSE doesn't like RW2?