Good answers above. I usually use 1200 dpi even on 35mm film with the Epson V600 scanner with good results. Skies are trouble in film and digital. The 'Luminous Landscape' has some excellent information in their videos in Lightroom on noise reduction, grain in film. Exposure and development matter. I always used Kodak's HC110 based on Arnold Gassan's 'Handbook for Contemporary Photography' suggestions. Primarily TriX or PlusX films. Rule of thumb, overexposure added grain and overdeveloped enlarged grain. Using LR I can smooth old grainy images but it is often at a loss of sharpness. The thing that has amazed me most now that I am into digital printing is how easy some of the old tasks like spotting, and dodging and burning have become. You may also want to check out: