In this short video tutorial, I will be showing you how to use the new depth of field settings provided by the physical renderer. The physical renderer is new to Cinema 4D (Release 13) and can produce great results if handled properly.
Before we begin, make sure that your project is ready and that you at least have a camera and a object set up in your hierarchy. Now the first step is to enable the physical renderer. To do this, simply click on the "edit render settings" button or just hit "CTRL + B" or "Command + B" on your keyboard. Now that you have your render settings window up, under "Renderer" click the drop down box and click on "physical" instead of "Standard." Now click on physical again (below "Stereoscopic") and check that "Depth of Field" is turned on. If not, do so now. You can also enable indirect illumination if you wish. After you have done that just close the "Render Settings" window.
Now click on your camera and make sure the "object" tab is present, scroll down and look for "focus distance." Adjust the focus distance according to where your subject is. Then simply go to the "Physical Tab" and adjust the "F-Stop." Think of the f-stop as how blurry you want the unfocussed areas to be, f/1.0 = maximum blur, f/22.0 = slightly blurry. Once you have done that, click the "Render Icon" and you're done.