How to get CGI renderings to look like if they were taken with a camera?
Just use one of these free photographic LUTs on top of your renderings with compressed highlights to implement a contrast that resembles what we are used to seeing in photography!
If you are using V-Ray, you can also use one of the Vray 5 VFB Presets in this pack to make things even more easy: Just load the preset and you are done! With an Exposure Layer with Highlight Burn and the LUT loaded in, your rendering should look already amazing on the contrast side. You can also use the presets that don't use an LUT and Curves etc. instead, so you have total control.
You can also use the mP_MagicLogFromVFB to bring your 32bit linear rendering into log-space (just click "Work in log" in the LookupTable layer) and save it out e.g. as a TIF file so you can then edit it in your photoediting software of choice!
Disclaimer: Except for the "Perfect 3D Imperfection Photographic LUTs" and the VFB Presets, these LUTs are not mine. I just want to share them with you after finding them on the Corona Renderer and Chaos Group forums. Kim Amland distributed the Corona Renderer LUTs and created two FStorm LUTs to mimick that contrast. They are freely available on the forums but are kind of hard to find, so I am hear to help out.