This is one of the advantages of shooting at a higher resolution than the intended target delivery resolution. When downscaling an image, the noise gets 'averaged' out of the image. For HD 1920x10280, a 2.7K resolution was a good choice before having to jump all the way to 4K. There's other technical reasons as well for shooting larger than intended use, but just re-enforcing the 'noise removal' process of downscaling an image.