Seems to me that it's more a lightning problem than a camera problem. When I'm lazy, i use my phone to take portraits and they look great. Try to stand next to a window to get all the benefits of outside light, avoid direct sunlight, clear curtains are great diffusers. The grainy pictures are typical from underexposed shot and ****py sensor pushed to their limits.
Edit : i don't see my quote for some reason :/


