I recently purchased a Sony A9 and took some pictures at a reasonably low ISO (640). I noticed some grainy-ness at 100% crop specifically in the background. Both pictures taken using a Sony 200-600 lens at 6.3 and 640 ISO. I would like to get some opinions what might be driving this:
1. This is typical
2. This is due to some settings I have that need to be changed that I'm not aware of
3. This is an issue with my particular camera
Raw files saved here:
https://www.dropbox.com/sh/lfbgxewtjamha2p/AADUsNd8Y360kdjHq910YTIsa?dl=0