It's pretty common for new users to Log Gammas thing that it means they no longer have to light anything...because "all that dynamic range", and try to "treat" Log like RAW. While C-log does give the user a RAW like experience (the ability to shift exposure in post), it's still a highly compressed 8 bit codec, and the limitations are obvious...noise in the shadows is a very common "new user bug" when shooting LOG. Here's another grade of your image...this one is probably closer to what you'd want it to look like. Notice now I've pushed the highlights up so the walls are reading white, and that's pushed most of the detail out of the window..the shirt and skin look better, but super graining still...this shows you what you should be doing with your exposure...if you want the walls to be white, and don't care about what's out the window...add 1-2 stops of exposure and your shadows will start to fall into line...or add some light to the subject. Good luck. You're well on your way to a real video camera